USB hard drive I/O slow speeds











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I have several Mediasonic ProBox HF2-SU3S2 with 4 drives - all with the same symptoms - extremely slow I/O (at best, about 10MB/s write). Each unit is configured with a software RAID 5 using mdadm with 4 drives.



It does appear it is connected to a USB 2.1 port and I expect it to be slower than USB 3.0 but 10MB/s seems suspiciously and ridiculously slow to me.



I can post smartctl -a output for each drive - but none of the drives appear to be failing and no errors are being logged into syslog related to the drives.



Here are the drives in the first unit:



Device Model:     ST2000DL003-9VT166
Device Model: ST2000DM001-1ER164
Device Model: ST2000DM001-1CH164
Device Model: ST2000DM001-1CH164


Drives in second unit:



Device Model:     ST2000DL003-9VT166
Device Model: ST2000DL003-9VT166
Device Model: WDC WD20EADS-00R6B0
Device Model: ST2000DL003-9VT166


Kernel version:



3.16.0-6-amd64 #1 SMP Debian 3.16.57-2


Output from mount:



/dev/md2 on /mnt/nas type ext4 (rw,relatime,stripe=256,data=ordered)
/dev/md3 on /mnt/nas2 type ext4 (rw,relatime,stripe=384,data=ordered)


Output from /proc/mdstat



md3 : active raid5 sdg[5] sdj[4] sdi[6] sdh[1]
5860150272 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]
bitmap: 0/15 pages [0KB], 65536KB chunk

md2 : active raid5 sdc1[0] sdf1[4] sdd1[6] sde1[5]
5860141056 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]


Tests using dd:



root@talon:/mnt/nas2# dd if=/dev/zero of=/mnt/nas2/testfile bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 71.1888 s, 15.1 MB/s

root@talon:/mnt/nas# dd if=/dev/zero of=/mnt/nas/testfile bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 80.8867 s, 13.3 MB/s


Output from mdadm --detail



/dev/md2:
Version : 1.2
Creation Time : Wed May 1 22:26:29 2013
Raid Level : raid5
Array Size : 5860141056 (5588.67 GiB 6000.78 GB)
Used Dev Size : 1953380352 (1862.89 GiB 2000.26 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent

Update Time : Wed Dec 5 21:29:12 2018
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 512K

Name : dev-vm01:0
UUID : dc4e42f6:3c3eb2f7:d6137927:51e328ef
Events : 21688

Number Major Minor RaidDevice State
0 8 33 0 active sync /dev/sdc1
5 8 65 1 active sync /dev/sde1
6 8 49 2 active sync /dev/sdd1
4 8 81 3 active sync /dev/sdf1

=-===-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

/dev/md3:
Version : 1.2
Creation Time : Sat Mar 10 11:08:14 2018
Raid Level : raid5
Array Size : 5860150272 (5588.67 GiB 6000.79 GB)
Used Dev Size : 1953383424 (1862.89 GiB 2000.26 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent

Intent Bitmap : Internal

Update Time : Wed Dec 5 21:23:31 2018
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 512K

Name : dragon:0
UUID : 70d8f410:462c6714:50231e20:b08aca81
Events : 151906

Number Major Minor RaidDevice State
5 8 96 0 active sync /dev/sdg
1 8 112 1 active sync /dev/sdh
6 8 128 2 active sync /dev/sdi
4 8 144 3 active sync /dev/sdj


More detailed information



root@talon:/mnt/nas# lsusb
Bus 009 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Bus 001 Device 002: ID 2109:3431
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

root@talon:/mnt/nas# lsusb -v -s 3:2

Bus 003 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 USB Mass Storage
bmAttributes 0xc0
Self Powered
MaxPower 50mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6 MSC Bulk-Only Transport
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 22
bNumDeviceCaps 2
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000002
Link Power Management (LPM) Supported
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 2047 micro seconds
Device Status: 0x0001
Self Powered


=-=-=-=-=-=-=-=-=-==-=-=-=-==-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

root@talon:/mnt/nas# lsusb -v -s 1:3

Bus 001 Device 003: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 USB Mass Storage
bmAttributes 0xc0
Self Powered
MaxPower 50mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6 MSC Bulk-Only Transport
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 22
bNumDeviceCaps 2
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000002
Link Power Management (LPM) Supported
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 2047 micro seconds
Device Status: 0x0001
Self Powered



"It does appear it is connected to a USB 2.1 port ". How did you confirm that?




See the output from lsusb.



bcdUSB               2.10



What motherboard or PC model is in use, and which USB port is used?




Motherboard: GA-78LMT-USB3
I will have to verify the revision and exact port.




Have you tried other ports on that PC, and if so, did you get the same result?




Yes - 2 units are plugged into the same desktop in different USB ports.
I even get these speeds from a Raspberry Pi.




USB 2.0 is very much slower than USB 3.0. A hard disk directly connected through USB 2.0 will hardly ever go above 20 MB/sec, whereas on USB 3.0 even small 2.5" disks reach 100 MB/sec.




The size of the disks don't matter. And I don't buy that - there are many resources that state the speed will be slow but faster than 10MB/s.




  • https://www.speedguide.net/faq/what-is-the-typical-usb-20-external-hard-drive-403

  • https://askubuntu.com/questions/41397/external-usb-hard-drives-what-speeds-should-be-expected

  • https://superuser.com/questions/664397/usb-3-0-vs-usb-2-0-for-external-hard-disks-drives


I plugged one of the units into a known USB 3.0 port:



Bus 002 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 3.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 9
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000


Now I am getting 3x the transfer speed but no where near what it should be:



root@talon:/mnt/nas2# dd if=/dev/zero of=/mnt/nas2/testfile4 bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 32.2737 s, 33.3 MB/s


Output from fdisk:



Disk /dev/sdc: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xe3b023b3

Device Boot Start End Sectors Size Id Type
/dev/sdc1 63 3907024064 3907024002 1.8T 83 Linux


Disk /dev/sdd: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x580e98e6

Device Boot Start End Sectors Size Id Type
/dev/sdd1 2048 3907029167 3907027120 1.8T 83 Linux


Disk /dev/sde: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x000d19a7

Device Boot Start End Sectors Size Id Type
/dev/sde1 2048 3907028991 3907026944 1.8T 83 Linux


Disk /dev/sdf: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc16a55ab

Device Boot Start End Sectors Size Id Type
/dev/sdf1 2048 3907029167 3907027120 1.8T 83 Linux

Disk /dev/sdg: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc91d9f27

Device Boot Start End Sectors Size Id Type
/dev/sdg1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdj: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x65cd7624

Device Boot Start End Sectors Size Id Type
/dev/sdj1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdi: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x03221dd4

Device Boot Start End Sectors Size Id Type
/dev/sdi1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdh: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc91329ab

Device Boot Start End Sectors Size Id Type
/dev/sdh1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect









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  • "It does appear it is connected to a USB 2.1 port ". How did you confirm that? What motherboard or PC model is in use, and which USB port is used? Have you tried other ports on that PC, and if so, did you get the same result? Please click on edit and add that to the original post, so all may see it. Also, on very long posts, it's OK to put the long text up somewhere others may see it and provide a link to the detail.
    – K7AAY
    2 days ago






  • 1




    USB 2.0 is very much slower than USB 3.0. A hard disk directly connected through USB 2.0 will hardly ever go above 20 MB/sec, whereas on USB 3.0 even small 2.5" disks reach 100 MB/sec. This being said, is there any chance that those Seagate drives have 4 KiB physical sectors, and if so, have you aligned data structures correctly?
    – AlexP
    2 days ago

















up vote
1
down vote

favorite












I have several Mediasonic ProBox HF2-SU3S2 with 4 drives - all with the same symptoms - extremely slow I/O (at best, about 10MB/s write). Each unit is configured with a software RAID 5 using mdadm with 4 drives.



It does appear it is connected to a USB 2.1 port and I expect it to be slower than USB 3.0 but 10MB/s seems suspiciously and ridiculously slow to me.



I can post smartctl -a output for each drive - but none of the drives appear to be failing and no errors are being logged into syslog related to the drives.



Here are the drives in the first unit:



Device Model:     ST2000DL003-9VT166
Device Model: ST2000DM001-1ER164
Device Model: ST2000DM001-1CH164
Device Model: ST2000DM001-1CH164


Drives in second unit:



Device Model:     ST2000DL003-9VT166
Device Model: ST2000DL003-9VT166
Device Model: WDC WD20EADS-00R6B0
Device Model: ST2000DL003-9VT166


Kernel version:



3.16.0-6-amd64 #1 SMP Debian 3.16.57-2


Output from mount:



/dev/md2 on /mnt/nas type ext4 (rw,relatime,stripe=256,data=ordered)
/dev/md3 on /mnt/nas2 type ext4 (rw,relatime,stripe=384,data=ordered)


Output from /proc/mdstat



md3 : active raid5 sdg[5] sdj[4] sdi[6] sdh[1]
5860150272 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]
bitmap: 0/15 pages [0KB], 65536KB chunk

md2 : active raid5 sdc1[0] sdf1[4] sdd1[6] sde1[5]
5860141056 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]


Tests using dd:



root@talon:/mnt/nas2# dd if=/dev/zero of=/mnt/nas2/testfile bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 71.1888 s, 15.1 MB/s

root@talon:/mnt/nas# dd if=/dev/zero of=/mnt/nas/testfile bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 80.8867 s, 13.3 MB/s


Output from mdadm --detail



/dev/md2:
Version : 1.2
Creation Time : Wed May 1 22:26:29 2013
Raid Level : raid5
Array Size : 5860141056 (5588.67 GiB 6000.78 GB)
Used Dev Size : 1953380352 (1862.89 GiB 2000.26 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent

Update Time : Wed Dec 5 21:29:12 2018
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 512K

Name : dev-vm01:0
UUID : dc4e42f6:3c3eb2f7:d6137927:51e328ef
Events : 21688

Number Major Minor RaidDevice State
0 8 33 0 active sync /dev/sdc1
5 8 65 1 active sync /dev/sde1
6 8 49 2 active sync /dev/sdd1
4 8 81 3 active sync /dev/sdf1

=-===-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

/dev/md3:
Version : 1.2
Creation Time : Sat Mar 10 11:08:14 2018
Raid Level : raid5
Array Size : 5860150272 (5588.67 GiB 6000.79 GB)
Used Dev Size : 1953383424 (1862.89 GiB 2000.26 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent

Intent Bitmap : Internal

Update Time : Wed Dec 5 21:23:31 2018
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 512K

Name : dragon:0
UUID : 70d8f410:462c6714:50231e20:b08aca81
Events : 151906

Number Major Minor RaidDevice State
5 8 96 0 active sync /dev/sdg
1 8 112 1 active sync /dev/sdh
6 8 128 2 active sync /dev/sdi
4 8 144 3 active sync /dev/sdj


More detailed information



root@talon:/mnt/nas# lsusb
Bus 009 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Bus 001 Device 002: ID 2109:3431
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

root@talon:/mnt/nas# lsusb -v -s 3:2

Bus 003 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 USB Mass Storage
bmAttributes 0xc0
Self Powered
MaxPower 50mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6 MSC Bulk-Only Transport
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 22
bNumDeviceCaps 2
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000002
Link Power Management (LPM) Supported
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 2047 micro seconds
Device Status: 0x0001
Self Powered


=-=-=-=-=-=-=-=-=-==-=-=-=-==-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

root@talon:/mnt/nas# lsusb -v -s 1:3

Bus 001 Device 003: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 USB Mass Storage
bmAttributes 0xc0
Self Powered
MaxPower 50mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6 MSC Bulk-Only Transport
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 22
bNumDeviceCaps 2
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000002
Link Power Management (LPM) Supported
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 2047 micro seconds
Device Status: 0x0001
Self Powered



"It does appear it is connected to a USB 2.1 port ". How did you confirm that?




See the output from lsusb.



bcdUSB               2.10



What motherboard or PC model is in use, and which USB port is used?




Motherboard: GA-78LMT-USB3
I will have to verify the revision and exact port.




Have you tried other ports on that PC, and if so, did you get the same result?




Yes - 2 units are plugged into the same desktop in different USB ports.
I even get these speeds from a Raspberry Pi.




USB 2.0 is very much slower than USB 3.0. A hard disk directly connected through USB 2.0 will hardly ever go above 20 MB/sec, whereas on USB 3.0 even small 2.5" disks reach 100 MB/sec.




The size of the disks don't matter. And I don't buy that - there are many resources that state the speed will be slow but faster than 10MB/s.




  • https://www.speedguide.net/faq/what-is-the-typical-usb-20-external-hard-drive-403

  • https://askubuntu.com/questions/41397/external-usb-hard-drives-what-speeds-should-be-expected

  • https://superuser.com/questions/664397/usb-3-0-vs-usb-2-0-for-external-hard-disks-drives


I plugged one of the units into a known USB 3.0 port:



Bus 002 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 3.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 9
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000


Now I am getting 3x the transfer speed but no where near what it should be:



root@talon:/mnt/nas2# dd if=/dev/zero of=/mnt/nas2/testfile4 bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 32.2737 s, 33.3 MB/s


Output from fdisk:



Disk /dev/sdc: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xe3b023b3

Device Boot Start End Sectors Size Id Type
/dev/sdc1 63 3907024064 3907024002 1.8T 83 Linux


Disk /dev/sdd: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x580e98e6

Device Boot Start End Sectors Size Id Type
/dev/sdd1 2048 3907029167 3907027120 1.8T 83 Linux


Disk /dev/sde: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x000d19a7

Device Boot Start End Sectors Size Id Type
/dev/sde1 2048 3907028991 3907026944 1.8T 83 Linux


Disk /dev/sdf: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc16a55ab

Device Boot Start End Sectors Size Id Type
/dev/sdf1 2048 3907029167 3907027120 1.8T 83 Linux

Disk /dev/sdg: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc91d9f27

Device Boot Start End Sectors Size Id Type
/dev/sdg1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdj: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x65cd7624

Device Boot Start End Sectors Size Id Type
/dev/sdj1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdi: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x03221dd4

Device Boot Start End Sectors Size Id Type
/dev/sdi1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdh: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc91329ab

Device Boot Start End Sectors Size Id Type
/dev/sdh1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect









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  • "It does appear it is connected to a USB 2.1 port ". How did you confirm that? What motherboard or PC model is in use, and which USB port is used? Have you tried other ports on that PC, and if so, did you get the same result? Please click on edit and add that to the original post, so all may see it. Also, on very long posts, it's OK to put the long text up somewhere others may see it and provide a link to the detail.
    – K7AAY
    2 days ago






  • 1




    USB 2.0 is very much slower than USB 3.0. A hard disk directly connected through USB 2.0 will hardly ever go above 20 MB/sec, whereas on USB 3.0 even small 2.5" disks reach 100 MB/sec. This being said, is there any chance that those Seagate drives have 4 KiB physical sectors, and if so, have you aligned data structures correctly?
    – AlexP
    2 days ago















up vote
1
down vote

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I have several Mediasonic ProBox HF2-SU3S2 with 4 drives - all with the same symptoms - extremely slow I/O (at best, about 10MB/s write). Each unit is configured with a software RAID 5 using mdadm with 4 drives.



It does appear it is connected to a USB 2.1 port and I expect it to be slower than USB 3.0 but 10MB/s seems suspiciously and ridiculously slow to me.



I can post smartctl -a output for each drive - but none of the drives appear to be failing and no errors are being logged into syslog related to the drives.



Here are the drives in the first unit:



Device Model:     ST2000DL003-9VT166
Device Model: ST2000DM001-1ER164
Device Model: ST2000DM001-1CH164
Device Model: ST2000DM001-1CH164


Drives in second unit:



Device Model:     ST2000DL003-9VT166
Device Model: ST2000DL003-9VT166
Device Model: WDC WD20EADS-00R6B0
Device Model: ST2000DL003-9VT166


Kernel version:



3.16.0-6-amd64 #1 SMP Debian 3.16.57-2


Output from mount:



/dev/md2 on /mnt/nas type ext4 (rw,relatime,stripe=256,data=ordered)
/dev/md3 on /mnt/nas2 type ext4 (rw,relatime,stripe=384,data=ordered)


Output from /proc/mdstat



md3 : active raid5 sdg[5] sdj[4] sdi[6] sdh[1]
5860150272 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]
bitmap: 0/15 pages [0KB], 65536KB chunk

md2 : active raid5 sdc1[0] sdf1[4] sdd1[6] sde1[5]
5860141056 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]


Tests using dd:



root@talon:/mnt/nas2# dd if=/dev/zero of=/mnt/nas2/testfile bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 71.1888 s, 15.1 MB/s

root@talon:/mnt/nas# dd if=/dev/zero of=/mnt/nas/testfile bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 80.8867 s, 13.3 MB/s


Output from mdadm --detail



/dev/md2:
Version : 1.2
Creation Time : Wed May 1 22:26:29 2013
Raid Level : raid5
Array Size : 5860141056 (5588.67 GiB 6000.78 GB)
Used Dev Size : 1953380352 (1862.89 GiB 2000.26 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent

Update Time : Wed Dec 5 21:29:12 2018
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 512K

Name : dev-vm01:0
UUID : dc4e42f6:3c3eb2f7:d6137927:51e328ef
Events : 21688

Number Major Minor RaidDevice State
0 8 33 0 active sync /dev/sdc1
5 8 65 1 active sync /dev/sde1
6 8 49 2 active sync /dev/sdd1
4 8 81 3 active sync /dev/sdf1

=-===-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

/dev/md3:
Version : 1.2
Creation Time : Sat Mar 10 11:08:14 2018
Raid Level : raid5
Array Size : 5860150272 (5588.67 GiB 6000.79 GB)
Used Dev Size : 1953383424 (1862.89 GiB 2000.26 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent

Intent Bitmap : Internal

Update Time : Wed Dec 5 21:23:31 2018
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 512K

Name : dragon:0
UUID : 70d8f410:462c6714:50231e20:b08aca81
Events : 151906

Number Major Minor RaidDevice State
5 8 96 0 active sync /dev/sdg
1 8 112 1 active sync /dev/sdh
6 8 128 2 active sync /dev/sdi
4 8 144 3 active sync /dev/sdj


More detailed information



root@talon:/mnt/nas# lsusb
Bus 009 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Bus 001 Device 002: ID 2109:3431
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

root@talon:/mnt/nas# lsusb -v -s 3:2

Bus 003 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 USB Mass Storage
bmAttributes 0xc0
Self Powered
MaxPower 50mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6 MSC Bulk-Only Transport
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 22
bNumDeviceCaps 2
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000002
Link Power Management (LPM) Supported
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 2047 micro seconds
Device Status: 0x0001
Self Powered


=-=-=-=-=-=-=-=-=-==-=-=-=-==-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

root@talon:/mnt/nas# lsusb -v -s 1:3

Bus 001 Device 003: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 USB Mass Storage
bmAttributes 0xc0
Self Powered
MaxPower 50mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6 MSC Bulk-Only Transport
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 22
bNumDeviceCaps 2
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000002
Link Power Management (LPM) Supported
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 2047 micro seconds
Device Status: 0x0001
Self Powered



"It does appear it is connected to a USB 2.1 port ". How did you confirm that?




See the output from lsusb.



bcdUSB               2.10



What motherboard or PC model is in use, and which USB port is used?




Motherboard: GA-78LMT-USB3
I will have to verify the revision and exact port.




Have you tried other ports on that PC, and if so, did you get the same result?




Yes - 2 units are plugged into the same desktop in different USB ports.
I even get these speeds from a Raspberry Pi.




USB 2.0 is very much slower than USB 3.0. A hard disk directly connected through USB 2.0 will hardly ever go above 20 MB/sec, whereas on USB 3.0 even small 2.5" disks reach 100 MB/sec.




The size of the disks don't matter. And I don't buy that - there are many resources that state the speed will be slow but faster than 10MB/s.




  • https://www.speedguide.net/faq/what-is-the-typical-usb-20-external-hard-drive-403

  • https://askubuntu.com/questions/41397/external-usb-hard-drives-what-speeds-should-be-expected

  • https://superuser.com/questions/664397/usb-3-0-vs-usb-2-0-for-external-hard-disks-drives


I plugged one of the units into a known USB 3.0 port:



Bus 002 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 3.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 9
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000


Now I am getting 3x the transfer speed but no where near what it should be:



root@talon:/mnt/nas2# dd if=/dev/zero of=/mnt/nas2/testfile4 bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 32.2737 s, 33.3 MB/s


Output from fdisk:



Disk /dev/sdc: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xe3b023b3

Device Boot Start End Sectors Size Id Type
/dev/sdc1 63 3907024064 3907024002 1.8T 83 Linux


Disk /dev/sdd: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x580e98e6

Device Boot Start End Sectors Size Id Type
/dev/sdd1 2048 3907029167 3907027120 1.8T 83 Linux


Disk /dev/sde: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x000d19a7

Device Boot Start End Sectors Size Id Type
/dev/sde1 2048 3907028991 3907026944 1.8T 83 Linux


Disk /dev/sdf: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc16a55ab

Device Boot Start End Sectors Size Id Type
/dev/sdf1 2048 3907029167 3907027120 1.8T 83 Linux

Disk /dev/sdg: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc91d9f27

Device Boot Start End Sectors Size Id Type
/dev/sdg1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdj: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x65cd7624

Device Boot Start End Sectors Size Id Type
/dev/sdj1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdi: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x03221dd4

Device Boot Start End Sectors Size Id Type
/dev/sdi1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdh: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc91329ab

Device Boot Start End Sectors Size Id Type
/dev/sdh1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect









share|improve this question









New contributor




Nathan Adams is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











I have several Mediasonic ProBox HF2-SU3S2 with 4 drives - all with the same symptoms - extremely slow I/O (at best, about 10MB/s write). Each unit is configured with a software RAID 5 using mdadm with 4 drives.



It does appear it is connected to a USB 2.1 port and I expect it to be slower than USB 3.0 but 10MB/s seems suspiciously and ridiculously slow to me.



I can post smartctl -a output for each drive - but none of the drives appear to be failing and no errors are being logged into syslog related to the drives.



Here are the drives in the first unit:



Device Model:     ST2000DL003-9VT166
Device Model: ST2000DM001-1ER164
Device Model: ST2000DM001-1CH164
Device Model: ST2000DM001-1CH164


Drives in second unit:



Device Model:     ST2000DL003-9VT166
Device Model: ST2000DL003-9VT166
Device Model: WDC WD20EADS-00R6B0
Device Model: ST2000DL003-9VT166


Kernel version:



3.16.0-6-amd64 #1 SMP Debian 3.16.57-2


Output from mount:



/dev/md2 on /mnt/nas type ext4 (rw,relatime,stripe=256,data=ordered)
/dev/md3 on /mnt/nas2 type ext4 (rw,relatime,stripe=384,data=ordered)


Output from /proc/mdstat



md3 : active raid5 sdg[5] sdj[4] sdi[6] sdh[1]
5860150272 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]
bitmap: 0/15 pages [0KB], 65536KB chunk

md2 : active raid5 sdc1[0] sdf1[4] sdd1[6] sde1[5]
5860141056 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]


Tests using dd:



root@talon:/mnt/nas2# dd if=/dev/zero of=/mnt/nas2/testfile bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 71.1888 s, 15.1 MB/s

root@talon:/mnt/nas# dd if=/dev/zero of=/mnt/nas/testfile bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 80.8867 s, 13.3 MB/s


Output from mdadm --detail



/dev/md2:
Version : 1.2
Creation Time : Wed May 1 22:26:29 2013
Raid Level : raid5
Array Size : 5860141056 (5588.67 GiB 6000.78 GB)
Used Dev Size : 1953380352 (1862.89 GiB 2000.26 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent

Update Time : Wed Dec 5 21:29:12 2018
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 512K

Name : dev-vm01:0
UUID : dc4e42f6:3c3eb2f7:d6137927:51e328ef
Events : 21688

Number Major Minor RaidDevice State
0 8 33 0 active sync /dev/sdc1
5 8 65 1 active sync /dev/sde1
6 8 49 2 active sync /dev/sdd1
4 8 81 3 active sync /dev/sdf1

=-===-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

/dev/md3:
Version : 1.2
Creation Time : Sat Mar 10 11:08:14 2018
Raid Level : raid5
Array Size : 5860150272 (5588.67 GiB 6000.79 GB)
Used Dev Size : 1953383424 (1862.89 GiB 2000.26 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent

Intent Bitmap : Internal

Update Time : Wed Dec 5 21:23:31 2018
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 512K

Name : dragon:0
UUID : 70d8f410:462c6714:50231e20:b08aca81
Events : 151906

Number Major Minor RaidDevice State
5 8 96 0 active sync /dev/sdg
1 8 112 1 active sync /dev/sdh
6 8 128 2 active sync /dev/sdi
4 8 144 3 active sync /dev/sdj


More detailed information



root@talon:/mnt/nas# lsusb
Bus 009 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Bus 001 Device 002: ID 2109:3431
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

root@talon:/mnt/nas# lsusb -v -s 3:2

Bus 003 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 USB Mass Storage
bmAttributes 0xc0
Self Powered
MaxPower 50mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6 MSC Bulk-Only Transport
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 22
bNumDeviceCaps 2
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000002
Link Power Management (LPM) Supported
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 2047 micro seconds
Device Status: 0x0001
Self Powered


=-=-=-=-=-=-=-=-=-==-=-=-=-==-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

root@talon:/mnt/nas# lsusb -v -s 1:3

Bus 001 Device 003: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 USB Mass Storage
bmAttributes 0xc0
Self Powered
MaxPower 50mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6 MSC Bulk-Only Transport
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 22
bNumDeviceCaps 2
USB 2.0 Extension Device Capability:
bLength 7
bDescriptorType 16
bDevCapabilityType 2
bmAttributes 0x00000002
Link Power Management (LPM) Supported
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 10 micro seconds
bU2DevExitLat 2047 micro seconds
Device Status: 0x0001
Self Powered



"It does appear it is connected to a USB 2.1 port ". How did you confirm that?




See the output from lsusb.



bcdUSB               2.10



What motherboard or PC model is in use, and which USB port is used?




Motherboard: GA-78LMT-USB3
I will have to verify the revision and exact port.




Have you tried other ports on that PC, and if so, did you get the same result?




Yes - 2 units are plugged into the same desktop in different USB ports.
I even get these speeds from a Raspberry Pi.




USB 2.0 is very much slower than USB 3.0. A hard disk directly connected through USB 2.0 will hardly ever go above 20 MB/sec, whereas on USB 3.0 even small 2.5" disks reach 100 MB/sec.




The size of the disks don't matter. And I don't buy that - there are many resources that state the speed will be slow but faster than 10MB/s.




  • https://www.speedguide.net/faq/what-is-the-typical-usb-20-external-hard-drive-403

  • https://askubuntu.com/questions/41397/external-usb-hard-drives-what-speeds-should-be-expected

  • https://superuser.com/questions/664397/usb-3-0-vs-usb-2-0-for-external-hard-disks-drives


I plugged one of the units into a known USB 3.0 port:



Bus 002 Device 002: ID 152d:0567 JMicron Technology Corp. / JMicron USA Technology Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 3.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 9
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x0567
bcdDevice 2.05
iManufacturer 10 JMicron
iProduct 11 USB to ATA/ATAPI Bridge
iSerial 5 152D00539000


Now I am getting 3x the transfer speed but no where near what it should be:



root@talon:/mnt/nas2# dd if=/dev/zero of=/mnt/nas2/testfile4 bs=1G count=1 oflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 32.2737 s, 33.3 MB/s


Output from fdisk:



Disk /dev/sdc: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xe3b023b3

Device Boot Start End Sectors Size Id Type
/dev/sdc1 63 3907024064 3907024002 1.8T 83 Linux


Disk /dev/sdd: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x580e98e6

Device Boot Start End Sectors Size Id Type
/dev/sdd1 2048 3907029167 3907027120 1.8T 83 Linux


Disk /dev/sde: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x000d19a7

Device Boot Start End Sectors Size Id Type
/dev/sde1 2048 3907028991 3907026944 1.8T 83 Linux


Disk /dev/sdf: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc16a55ab

Device Boot Start End Sectors Size Id Type
/dev/sdf1 2048 3907029167 3907027120 1.8T 83 Linux

Disk /dev/sdg: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc91d9f27

Device Boot Start End Sectors Size Id Type
/dev/sdg1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdj: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x65cd7624

Device Boot Start End Sectors Size Id Type
/dev/sdj1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdi: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x03221dd4

Device Boot Start End Sectors Size Id Type
/dev/sdi1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect


Disk /dev/sdh: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc91329ab

Device Boot Start End Sectors Size Id Type
/dev/sdh1 2048 3907028991 3907026944 1.8T fd Linux raid autodetect






usb-drive io mdadm software-raid






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share|improve this question




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edited 2 days ago





















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asked Dec 7 at 3:51









Nathan Adams

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Nathan Adams is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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  • "It does appear it is connected to a USB 2.1 port ". How did you confirm that? What motherboard or PC model is in use, and which USB port is used? Have you tried other ports on that PC, and if so, did you get the same result? Please click on edit and add that to the original post, so all may see it. Also, on very long posts, it's OK to put the long text up somewhere others may see it and provide a link to the detail.
    – K7AAY
    2 days ago






  • 1




    USB 2.0 is very much slower than USB 3.0. A hard disk directly connected through USB 2.0 will hardly ever go above 20 MB/sec, whereas on USB 3.0 even small 2.5" disks reach 100 MB/sec. This being said, is there any chance that those Seagate drives have 4 KiB physical sectors, and if so, have you aligned data structures correctly?
    – AlexP
    2 days ago




















  • "It does appear it is connected to a USB 2.1 port ". How did you confirm that? What motherboard or PC model is in use, and which USB port is used? Have you tried other ports on that PC, and if so, did you get the same result? Please click on edit and add that to the original post, so all may see it. Also, on very long posts, it's OK to put the long text up somewhere others may see it and provide a link to the detail.
    – K7AAY
    2 days ago






  • 1




    USB 2.0 is very much slower than USB 3.0. A hard disk directly connected through USB 2.0 will hardly ever go above 20 MB/sec, whereas on USB 3.0 even small 2.5" disks reach 100 MB/sec. This being said, is there any chance that those Seagate drives have 4 KiB physical sectors, and if so, have you aligned data structures correctly?
    – AlexP
    2 days ago


















"It does appear it is connected to a USB 2.1 port ". How did you confirm that? What motherboard or PC model is in use, and which USB port is used? Have you tried other ports on that PC, and if so, did you get the same result? Please click on edit and add that to the original post, so all may see it. Also, on very long posts, it's OK to put the long text up somewhere others may see it and provide a link to the detail.
– K7AAY
2 days ago




"It does appear it is connected to a USB 2.1 port ". How did you confirm that? What motherboard or PC model is in use, and which USB port is used? Have you tried other ports on that PC, and if so, did you get the same result? Please click on edit and add that to the original post, so all may see it. Also, on very long posts, it's OK to put the long text up somewhere others may see it and provide a link to the detail.
– K7AAY
2 days ago




1




1




USB 2.0 is very much slower than USB 3.0. A hard disk directly connected through USB 2.0 will hardly ever go above 20 MB/sec, whereas on USB 3.0 even small 2.5" disks reach 100 MB/sec. This being said, is there any chance that those Seagate drives have 4 KiB physical sectors, and if so, have you aligned data structures correctly?
– AlexP
2 days ago






USB 2.0 is very much slower than USB 3.0. A hard disk directly connected through USB 2.0 will hardly ever go above 20 MB/sec, whereas on USB 3.0 even small 2.5" disks reach 100 MB/sec. This being said, is there any chance that those Seagate drives have 4 KiB physical sectors, and if so, have you aligned data structures correctly?
– AlexP
2 days ago












1 Answer
1






active

oldest

votes

















up vote
1
down vote













USB2 speed (60MB/s) divided by the number of drives in RAID you are writing to at the same time (4) is equal to 15 MB/s, throw in some overhead and 10 sounds reasonable.



To test unmount the RAID to make sure it's not using the bus then run



hdparm -Tt /dev/sdh





share|improve this answer























  • That makes sense for USB 2.0 but I have it plugged into a USB 3.0 port and let's assume the transfer speed is 500MB/s - dividing by 4 should yield at least 100MB/s transfer rate but according to the dd test I only got 33MB/s. I'm going to update and try a newer kernel and see if that helps.
    – Nathan Adams
    12 hours ago










  • @NathanAdams Let me know when you have hdparm and lsusb output. Also check UAS on 4.14.87 kernel.
    – user1133275
    11 hours ago











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up vote
1
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USB2 speed (60MB/s) divided by the number of drives in RAID you are writing to at the same time (4) is equal to 15 MB/s, throw in some overhead and 10 sounds reasonable.



To test unmount the RAID to make sure it's not using the bus then run



hdparm -Tt /dev/sdh





share|improve this answer























  • That makes sense for USB 2.0 but I have it plugged into a USB 3.0 port and let's assume the transfer speed is 500MB/s - dividing by 4 should yield at least 100MB/s transfer rate but according to the dd test I only got 33MB/s. I'm going to update and try a newer kernel and see if that helps.
    – Nathan Adams
    12 hours ago










  • @NathanAdams Let me know when you have hdparm and lsusb output. Also check UAS on 4.14.87 kernel.
    – user1133275
    11 hours ago















up vote
1
down vote













USB2 speed (60MB/s) divided by the number of drives in RAID you are writing to at the same time (4) is equal to 15 MB/s, throw in some overhead and 10 sounds reasonable.



To test unmount the RAID to make sure it's not using the bus then run



hdparm -Tt /dev/sdh





share|improve this answer























  • That makes sense for USB 2.0 but I have it plugged into a USB 3.0 port and let's assume the transfer speed is 500MB/s - dividing by 4 should yield at least 100MB/s transfer rate but according to the dd test I only got 33MB/s. I'm going to update and try a newer kernel and see if that helps.
    – Nathan Adams
    12 hours ago










  • @NathanAdams Let me know when you have hdparm and lsusb output. Also check UAS on 4.14.87 kernel.
    – user1133275
    11 hours ago













up vote
1
down vote










up vote
1
down vote









USB2 speed (60MB/s) divided by the number of drives in RAID you are writing to at the same time (4) is equal to 15 MB/s, throw in some overhead and 10 sounds reasonable.



To test unmount the RAID to make sure it's not using the bus then run



hdparm -Tt /dev/sdh





share|improve this answer














USB2 speed (60MB/s) divided by the number of drives in RAID you are writing to at the same time (4) is equal to 15 MB/s, throw in some overhead and 10 sounds reasonable.



To test unmount the RAID to make sure it's not using the bus then run



hdparm -Tt /dev/sdh






share|improve this answer














share|improve this answer



share|improve this answer








edited 2 days ago

























answered 2 days ago









user1133275

2,750415




2,750415












  • That makes sense for USB 2.0 but I have it plugged into a USB 3.0 port and let's assume the transfer speed is 500MB/s - dividing by 4 should yield at least 100MB/s transfer rate but according to the dd test I only got 33MB/s. I'm going to update and try a newer kernel and see if that helps.
    – Nathan Adams
    12 hours ago










  • @NathanAdams Let me know when you have hdparm and lsusb output. Also check UAS on 4.14.87 kernel.
    – user1133275
    11 hours ago


















  • That makes sense for USB 2.0 but I have it plugged into a USB 3.0 port and let's assume the transfer speed is 500MB/s - dividing by 4 should yield at least 100MB/s transfer rate but according to the dd test I only got 33MB/s. I'm going to update and try a newer kernel and see if that helps.
    – Nathan Adams
    12 hours ago










  • @NathanAdams Let me know when you have hdparm and lsusb output. Also check UAS on 4.14.87 kernel.
    – user1133275
    11 hours ago
















That makes sense for USB 2.0 but I have it plugged into a USB 3.0 port and let's assume the transfer speed is 500MB/s - dividing by 4 should yield at least 100MB/s transfer rate but according to the dd test I only got 33MB/s. I'm going to update and try a newer kernel and see if that helps.
– Nathan Adams
12 hours ago




That makes sense for USB 2.0 but I have it plugged into a USB 3.0 port and let's assume the transfer speed is 500MB/s - dividing by 4 should yield at least 100MB/s transfer rate but according to the dd test I only got 33MB/s. I'm going to update and try a newer kernel and see if that helps.
– Nathan Adams
12 hours ago












@NathanAdams Let me know when you have hdparm and lsusb output. Also check UAS on 4.14.87 kernel.
– user1133275
11 hours ago




@NathanAdams Let me know when you have hdparm and lsusb output. Also check UAS on 4.14.87 kernel.
– user1133275
11 hours ago










Nathan Adams is a new contributor. Be nice, and check out our Code of Conduct.










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