Meaning of root in GRUB config file
Refering to here
with a configuration as
grub> root (hd0,0)
grub> kernel /vmlinuz-i686-up-4GB root=/dev/hda9
grub> boot
The preceding is usually sufficient to boot a Linux box. The standalone root statement tells the partition containing the kernel. The kernel statement describes the path and filename, within the partition containing the kernel of the kernel. The argument to the root= argument to the kernel statement tells the partition containing /sbin/init, which of course turns out to be the root partition in the booted system.
Be careful of these duelling root keywords. The standalone one is the root as seen from grub, and contains the kernel. The argument to the kernel statement is the root as seen from the fully booted system, and contains /sbin/init.
I don't quite get the meaning of the 2 root configs. Does it mean the OS stays on /dev/hda9 to be mounted on (hd0, 0), or the OS is /vmlinuz to be mounted to /dev/had9 ?
mount configuration root grub grub-legacy
asked Jan 15 '16 at 11:07
KennyKenny
51511019
add a comment |
Refering to here
with a configuration as
grub> root (hd0,0)
grub> kernel /vmlinuz-i686-up-4GB root=/dev/hda9
grub> boot
The preceding is usually sufficient to boot a Linux box. The standalone root statement tells the partition containing the kernel. The kernel statement describes the path and filename, within the partition containing the kernel of the kernel. The argument to the root= argument to the kernel statement tells the partition containing /sbin/init, which of course turns out to be the root partition in the booted system.
Be careful of these duelling root keywords. The standalone one is the root as seen from grub, and contains the kernel. The argument to the kernel statement is the root as seen from the fully booted system, and contains /sbin/init.
I don't quite get the meaning of the 2 root configs. Does it mean the OS stays on /dev/hda9 to be mounted on (hd0, 0), or the OS is /vmlinuz to be mounted to /dev/had9 ?
mount configuration root grub grub-legacy
asked Jan 15 '16 at 11:07
KennyKenny
51511019
add a comment |
Refering to here
with a configuration as
grub> root (hd0,0)
grub> kernel /vmlinuz-i686-up-4GB root=/dev/hda9
grub> boot
The preceding is usually sufficient to boot a Linux box. The standalone root statement tells the partition containing the kernel. The kernel statement describes the path and filename, within the partition containing the kernel of the kernel. The argument to the root= argument to the kernel statement tells the partition containing /sbin/init, which of course turns out to be the root partition in the booted system.
Be careful of these duelling root keywords. The standalone one is the root as seen from grub, and contains the kernel. The argument to the kernel statement is the root as seen from the fully booted system, and contains /sbin/init.
I don't quite get the meaning of the 2 root configs. Does it mean the OS stays on /dev/hda9 to be mounted on (hd0, 0), or the OS is /vmlinuz to be mounted to /dev/had9 ?
mount configuration root grub grub-legacy
asked Jan 15 '16 at 11:07
KennyKenny
51511019
Refering to here
with a configuration as
grub> root (hd0,0)
grub> kernel /vmlinuz-i686-up-4GB root=/dev/hda9
grub> boot
The preceding is usually sufficient to boot a Linux box. The standalone root statement tells the partition containing the kernel. The kernel statement describes the path and filename, within the partition containing the kernel of the kernel. The argument to the root= argument to the kernel statement tells the partition containing /sbin/init, which of course turns out to be the root partition in the booted system.
Be careful of these duelling root keywords. The standalone one is the root as seen from grub, and contains the kernel. The argument to the kernel statement is the root as seen from the fully booted system, and contains /sbin/init.
I don't quite get the meaning of the 2 root configs. Does it mean the OS stays on /dev/hda9 to be mounted on (hd0, 0), or the OS is /vmlinuz to be mounted to /dev/had9 ?
mount configuration root grub grub-legacy
mount configuration root grub grub-legacy
asked Jan 15 '16 at 11:07
KennyKenny
51511019
asked Jan 15 '16 at 11:07
KennyKenny
51511019
asked Jan 15 '16 at 11:07
KennyKenny
51511019
asked Jan 15 '16 at 11:07
KennyKenny
51511019
asked Jan 15 '16 at 11:07
KennyKenny
51511019
51511019
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
root (hd0,0) - Configures the root partition for GRUB, such as (hd0,0) first hard disk, first Partition and mounts the partition.
kernel /vmlinuz-i686-up-4GB root=/dev/hda9 - Specifies the kernel location which is inside the /boot folder. This location is related to the root(hd0,0) statement.The root partition is specified according to the Linux naming convention (/dev/hda9/)
The Kernel image will be mounted on root file system (/dev/hda9)
answered Jan 15 '16 at 11:34
Siddharth sharmaSiddharth sharma
1214
1
The kernel image isn't "mounted on [the] root file system", the root file system is (by the kernel). :-)
– Chris Down
Jan 15 '16 at 12:10
1
Basically root= tells the partition containing /sbin/init, which of course turns out to be the root partition in the booted system.
– Siddharth sharma
Jan 15 '16 at 12:16
Can you elaborate ? You mentioned the root partion as (hd0,0) and later said the root partition /dev/hda9. The root partition for GRUB, from my understanding, is where the GRUb config files stays. But it has nothing to do with where the OS is. For example here, GRUB config is read from (hd0,0), the OS is in /vmlinuz which will be mounted at /dev/hda9
– Kenny
Jan 15 '16 at 14:04
1
@Kenny root(hd0,0) tells the grub where it's configuration files are located. In this case, they can be found under (hd0,0)/boot/grub. And, kernel /vmlinuz-i686-up-4GB root=/dev/hda9 specifies the actual kernel image location from where it can be read, which is inside the /boot folder. There can be many kernel images. root=/dev/hda9 specifies the location of your root ( "/") partition of the OS.
– Siddharth sharma
Jan 16 '16 at 5:21
add a comment |
The way I have my system, on /dev/sda1-3.
The first partition of my hardisk is sda1 and contains the boot partition.
I have a swap drive in sda2. I have my main partition in sda3. Sda3 holds the root "/" directory and all its subdirectories like /etc, and /usr.
In my Grub.cfg I have set
set root=(hostdisk//dev/sda,gpt1)
This lets the bootloader find the kernel files before any filesystem is ready. Technically you are booting sda1.
When the kernel loads and mounts the drives in the fstab, root "/" itself is on sda3, but /boot (the files that booted) are mounted to sda1.
linux /kernel-genkernel-x86_64-4.9.144-3 root=/dev/sda3 real_root=/dev/sda3 rootfstype=ext4
initrd /early_ucode.cpio /initramfs-genkernel-x86_64-4.9.144-3
So even though the system booted with the files on sda1, the root "/" is really on sda3.
answered 42 mins ago
EngineerEngineer
1014
add a comment |
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2 Answers
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root (hd0,0) - Configures the root partition for GRUB, such as (hd0,0) first hard disk, first Partition and mounts the partition.
kernel /vmlinuz-i686-up-4GB root=/dev/hda9 - Specifies the kernel location which is inside the /boot folder. This location is related to the root(hd0,0) statement.The root partition is specified according to the Linux naming convention (/dev/hda9/)
The Kernel image will be mounted on root file system (/dev/hda9)
answered Jan 15 '16 at 11:34
Siddharth sharmaSiddharth sharma
1214
1
The kernel image isn't "mounted on [the] root file system", the root file system is (by the kernel). :-)
– Chris Down
Jan 15 '16 at 12:10
1
Basically root= tells the partition containing /sbin/init, which of course turns out to be the root partition in the booted system.
– Siddharth sharma
Jan 15 '16 at 12:16
Can you elaborate ? You mentioned the root partion as (hd0,0) and later said the root partition /dev/hda9. The root partition for GRUB, from my understanding, is where the GRUb config files stays. But it has nothing to do with where the OS is. For example here, GRUB config is read from (hd0,0), the OS is in /vmlinuz which will be mounted at /dev/hda9
– Kenny
Jan 15 '16 at 14:04
1
@Kenny root(hd0,0) tells the grub where it's configuration files are located. In this case, they can be found under (hd0,0)/boot/grub. And, kernel /vmlinuz-i686-up-4GB root=/dev/hda9 specifies the actual kernel image location from where it can be read, which is inside the /boot folder. There can be many kernel images. root=/dev/hda9 specifies the location of your root ( "/") partition of the OS.
– Siddharth sharma
Jan 16 '16 at 5:21
add a comment |
root (hd0,0) - Configures the root partition for GRUB, such as (hd0,0) first hard disk, first Partition and mounts the partition.
kernel /vmlinuz-i686-up-4GB root=/dev/hda9 - Specifies the kernel location which is inside the /boot folder. This location is related to the root(hd0,0) statement.The root partition is specified according to the Linux naming convention (/dev/hda9/)
The Kernel image will be mounted on root file system (/dev/hda9)
answered Jan 15 '16 at 11:34
Siddharth sharmaSiddharth sharma
1214
1
The kernel image isn't "mounted on [the] root file system", the root file system is (by the kernel). :-)
– Chris Down
Jan 15 '16 at 12:10
1
Basically root= tells the partition containing /sbin/init, which of course turns out to be the root partition in the booted system.
– Siddharth sharma
Jan 15 '16 at 12:16
Can you elaborate ? You mentioned the root partion as (hd0,0) and later said the root partition /dev/hda9. The root partition for GRUB, from my understanding, is where the GRUb config files stays. But it has nothing to do with where the OS is. For example here, GRUB config is read from (hd0,0), the OS is in /vmlinuz which will be mounted at /dev/hda9
– Kenny
Jan 15 '16 at 14:04
1
@Kenny root(hd0,0) tells the grub where it's configuration files are located. In this case, they can be found under (hd0,0)/boot/grub. And, kernel /vmlinuz-i686-up-4GB root=/dev/hda9 specifies the actual kernel image location from where it can be read, which is inside the /boot folder. There can be many kernel images. root=/dev/hda9 specifies the location of your root ( "/") partition of the OS.
– Siddharth sharma
Jan 16 '16 at 5:21
add a comment |
root (hd0,0) - Configures the root partition for GRUB, such as (hd0,0) first hard disk, first Partition and mounts the partition.
kernel /vmlinuz-i686-up-4GB root=/dev/hda9 - Specifies the kernel location which is inside the /boot folder. This location is related to the root(hd0,0) statement.The root partition is specified according to the Linux naming convention (/dev/hda9/)
The Kernel image will be mounted on root file system (/dev/hda9)
answered Jan 15 '16 at 11:34
Siddharth sharmaSiddharth sharma
1214
root (hd0,0) - Configures the root partition for GRUB, such as (hd0,0) first hard disk, first Partition and mounts the partition.
kernel /vmlinuz-i686-up-4GB root=/dev/hda9 - Specifies the kernel location which is inside the /boot folder. This location is related to the root(hd0,0) statement.The root partition is specified according to the Linux naming convention (/dev/hda9/)
The Kernel image will be mounted on root file system (/dev/hda9)
answered Jan 15 '16 at 11:34
Siddharth sharmaSiddharth sharma
1214
answered Jan 15 '16 at 11:34
Siddharth sharmaSiddharth sharma
1214
answered Jan 15 '16 at 11:34
Siddharth sharmaSiddharth sharma
1214
answered Jan 15 '16 at 11:34
Siddharth sharmaSiddharth sharma
1214
1214
1
The kernel image isn't "mounted on [the] root file system", the root file system is (by the kernel). :-)
– Chris Down
Jan 15 '16 at 12:10
1
Basically root= tells the partition containing /sbin/init, which of course turns out to be the root partition in the booted system.
– Siddharth sharma
Jan 15 '16 at 12:16
Can you elaborate ? You mentioned the root partion as (hd0,0) and later said the root partition /dev/hda9. The root partition for GRUB, from my understanding, is where the GRUb config files stays. But it has nothing to do with where the OS is. For example here, GRUB config is read from (hd0,0), the OS is in /vmlinuz which will be mounted at /dev/hda9
– Kenny
Jan 15 '16 at 14:04
1
@Kenny root(hd0,0) tells the grub where it's configuration files are located. In this case, they can be found under (hd0,0)/boot/grub. And, kernel /vmlinuz-i686-up-4GB root=/dev/hda9 specifies the actual kernel image location from where it can be read, which is inside the /boot folder. There can be many kernel images. root=/dev/hda9 specifies the location of your root ( "/") partition of the OS.
– Siddharth sharma
Jan 16 '16 at 5:21
add a comment |
1
The kernel image isn't "mounted on [the] root file system", the root file system is (by the kernel). :-)
– Chris Down
Jan 15 '16 at 12:10
1
Basically root= tells the partition containing /sbin/init, which of course turns out to be the root partition in the booted system.
– Siddharth sharma
Jan 15 '16 at 12:16
Can you elaborate ? You mentioned the root partion as (hd0,0) and later said the root partition /dev/hda9. The root partition for GRUB, from my understanding, is where the GRUb config files stays. But it has nothing to do with where the OS is. For example here, GRUB config is read from (hd0,0), the OS is in /vmlinuz which will be mounted at /dev/hda9
– Kenny
Jan 15 '16 at 14:04
1
@Kenny root(hd0,0) tells the grub where it's configuration files are located. In this case, they can be found under (hd0,0)/boot/grub. And, kernel /vmlinuz-i686-up-4GB root=/dev/hda9 specifies the actual kernel image location from where it can be read, which is inside the /boot folder. There can be many kernel images. root=/dev/hda9 specifies the location of your root ( "/") partition of the OS.
– Siddharth sharma
Jan 16 '16 at 5:21
1
1
The kernel image isn't "mounted on [the] root file system", the root file system is (by the kernel). :-)
– Chris Down
Jan 15 '16 at 12:10
The kernel image isn't "mounted on [the] root file system", the root file system is (by the kernel). :-)
– Chris Down
Jan 15 '16 at 12:10
1
1
Basically root= tells the partition containing /sbin/init, which of course turns out to be the root partition in the booted system.
– Siddharth sharma
Jan 15 '16 at 12:16
Basically root= tells the partition containing /sbin/init, which of course turns out to be the root partition in the booted system.
– Siddharth sharma
Jan 15 '16 at 12:16
Can you elaborate ? You mentioned the root partion as (hd0,0) and later said the root partition /dev/hda9. The root partition for GRUB, from my understanding, is where the GRUb config files stays. But it has nothing to do with where the OS is. For example here, GRUB config is read from (hd0,0), the OS is in /vmlinuz which will be mounted at /dev/hda9
– Kenny
Jan 15 '16 at 14:04
Can you elaborate ? You mentioned the root partion as (hd0,0) and later said the root partition /dev/hda9. The root partition for GRUB, from my understanding, is where the GRUb config files stays. But it has nothing to do with where the OS is. For example here, GRUB config is read from (hd0,0), the OS is in /vmlinuz which will be mounted at /dev/hda9
– Kenny
Jan 15 '16 at 14:04
1
1
@Kenny root(hd0,0) tells the grub where it's configuration files are located. In this case, they can be found under (hd0,0)/boot/grub. And, kernel /vmlinuz-i686-up-4GB root=/dev/hda9 specifies the actual kernel image location from where it can be read, which is inside the /boot folder. There can be many kernel images. root=/dev/hda9 specifies the location of your root ( "/") partition of the OS.
– Siddharth sharma
Jan 16 '16 at 5:21
@Kenny root(hd0,0) tells the grub where it's configuration files are located. In this case, they can be found under (hd0,0)/boot/grub. And, kernel /vmlinuz-i686-up-4GB root=/dev/hda9 specifies the actual kernel image location from where it can be read, which is inside the /boot folder. There can be many kernel images. root=/dev/hda9 specifies the location of your root ( "/") partition of the OS.
– Siddharth sharma
Jan 16 '16 at 5:21
add a comment |
The way I have my system, on /dev/sda1-3.
The first partition of my hardisk is sda1 and contains the boot partition.
I have a swap drive in sda2. I have my main partition in sda3. Sda3 holds the root "/" directory and all its subdirectories like /etc, and /usr.
In my Grub.cfg I have set
set root=(hostdisk//dev/sda,gpt1)
This lets the bootloader find the kernel files before any filesystem is ready. Technically you are booting sda1.
When the kernel loads and mounts the drives in the fstab, root "/" itself is on sda3, but /boot (the files that booted) are mounted to sda1.
linux /kernel-genkernel-x86_64-4.9.144-3 root=/dev/sda3 real_root=/dev/sda3 rootfstype=ext4
initrd /early_ucode.cpio /initramfs-genkernel-x86_64-4.9.144-3
So even though the system booted with the files on sda1, the root "/" is really on sda3.
answered 42 mins ago
EngineerEngineer
1014
add a comment |
The way I have my system, on /dev/sda1-3.
The first partition of my hardisk is sda1 and contains the boot partition.
I have a swap drive in sda2. I have my main partition in sda3. Sda3 holds the root "/" directory and all its subdirectories like /etc, and /usr.
In my Grub.cfg I have set
set root=(hostdisk//dev/sda,gpt1)
This lets the bootloader find the kernel files before any filesystem is ready. Technically you are booting sda1.
When the kernel loads and mounts the drives in the fstab, root "/" itself is on sda3, but /boot (the files that booted) are mounted to sda1.
linux /kernel-genkernel-x86_64-4.9.144-3 root=/dev/sda3 real_root=/dev/sda3 rootfstype=ext4
initrd /early_ucode.cpio /initramfs-genkernel-x86_64-4.9.144-3
So even though the system booted with the files on sda1, the root "/" is really on sda3.
answered 42 mins ago
EngineerEngineer
1014
add a comment |
The way I have my system, on /dev/sda1-3.
The first partition of my hardisk is sda1 and contains the boot partition.
I have a swap drive in sda2. I have my main partition in sda3. Sda3 holds the root "/" directory and all its subdirectories like /etc, and /usr.
In my Grub.cfg I have set
set root=(hostdisk//dev/sda,gpt1)
This lets the bootloader find the kernel files before any filesystem is ready. Technically you are booting sda1.
When the kernel loads and mounts the drives in the fstab, root "/" itself is on sda3, but /boot (the files that booted) are mounted to sda1.
linux /kernel-genkernel-x86_64-4.9.144-3 root=/dev/sda3 real_root=/dev/sda3 rootfstype=ext4
initrd /early_ucode.cpio /initramfs-genkernel-x86_64-4.9.144-3
So even though the system booted with the files on sda1, the root "/" is really on sda3.
answered 42 mins ago
EngineerEngineer
1014
The way I have my system, on /dev/sda1-3.
The first partition of my hardisk is sda1 and contains the boot partition.
I have a swap drive in sda2. I have my main partition in sda3. Sda3 holds the root "/" directory and all its subdirectories like /etc, and /usr.
In my Grub.cfg I have set
set root=(hostdisk//dev/sda,gpt1)
This lets the bootloader find the kernel files before any filesystem is ready. Technically you are booting sda1.
When the kernel loads and mounts the drives in the fstab, root "/" itself is on sda3, but /boot (the files that booted) are mounted to sda1.
linux /kernel-genkernel-x86_64-4.9.144-3 root=/dev/sda3 real_root=/dev/sda3 rootfstype=ext4
initrd /early_ucode.cpio /initramfs-genkernel-x86_64-4.9.144-3
So even though the system booted with the files on sda1, the root "/" is really on sda3.
answered 42 mins ago
EngineerEngineer
1014
edited 29 mins ago
answered 42 mins ago
EngineerEngineer
1014
answered 42 mins ago
EngineerEngineer
1014
answered 42 mins ago
EngineerEngineer
1014
1014
add a comment |
add a comment |
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