does Linux kernel alter unmounted ext4 partitions?
When the 4.9 Linux kernel boots and recognizes the presence of and MMC partition, does it alter the partition in any way if the partition is not mounted?
I pre-calculated the sha256 of a "filesystem.img" at build time (ext4.)
I apply my file system to an MMC partition as follows:
dd if=myfilesystem.img of=/dev/mmcblk0p2 bs=4096 count=XYZABC
I can read the partition back and verify that the flash was correct:
dd if=/dev/mmcblk0p2 bs=496 count=XYZABC | sha256sum
Journaling is disabled. I can manually mount the file system read-only and unmount as much as I want. The sha256 remains the same.
However, if I reboot and run the checksum again, the sha256 on the partition comes out different. The partition I wrote to before rebooting is not mounted. But it is recognized as mmcblk0p2 by the kernel.
Does the kernel alter the data in a partition in any way before it is mounted?
linux ext4
asked 28 mins ago
Eric Texley
162
add a comment |
When the 4.9 Linux kernel boots and recognizes the presence of and MMC partition, does it alter the partition in any way if the partition is not mounted?
I pre-calculated the sha256 of a "filesystem.img" at build time (ext4.)
I apply my file system to an MMC partition as follows:
dd if=myfilesystem.img of=/dev/mmcblk0p2 bs=4096 count=XYZABC
I can read the partition back and verify that the flash was correct:
dd if=/dev/mmcblk0p2 bs=496 count=XYZABC | sha256sum
Journaling is disabled. I can manually mount the file system read-only and unmount as much as I want. The sha256 remains the same.
However, if I reboot and run the checksum again, the sha256 on the partition comes out different. The partition I wrote to before rebooting is not mounted. But it is recognized as mmcblk0p2 by the kernel.
Does the kernel alter the data in a partition in any way before it is mounted?
linux ext4
asked 28 mins ago
Eric Texley
162
add a comment |
When the 4.9 Linux kernel boots and recognizes the presence of and MMC partition, does it alter the partition in any way if the partition is not mounted?
I pre-calculated the sha256 of a "filesystem.img" at build time (ext4.)
I apply my file system to an MMC partition as follows:
dd if=myfilesystem.img of=/dev/mmcblk0p2 bs=4096 count=XYZABC
I can read the partition back and verify that the flash was correct:
dd if=/dev/mmcblk0p2 bs=496 count=XYZABC | sha256sum
Journaling is disabled. I can manually mount the file system read-only and unmount as much as I want. The sha256 remains the same.
However, if I reboot and run the checksum again, the sha256 on the partition comes out different. The partition I wrote to before rebooting is not mounted. But it is recognized as mmcblk0p2 by the kernel.
Does the kernel alter the data in a partition in any way before it is mounted?
linux ext4
asked 28 mins ago
Eric Texley
162
When the 4.9 Linux kernel boots and recognizes the presence of and MMC partition, does it alter the partition in any way if the partition is not mounted?
I pre-calculated the sha256 of a "filesystem.img" at build time (ext4.)
I apply my file system to an MMC partition as follows:
dd if=myfilesystem.img of=/dev/mmcblk0p2 bs=4096 count=XYZABC
I can read the partition back and verify that the flash was correct:
dd if=/dev/mmcblk0p2 bs=496 count=XYZABC | sha256sum
Journaling is disabled. I can manually mount the file system read-only and unmount as much as I want. The sha256 remains the same.
However, if I reboot and run the checksum again, the sha256 on the partition comes out different. The partition I wrote to before rebooting is not mounted. But it is recognized as mmcblk0p2 by the kernel.
Does the kernel alter the data in a partition in any way before it is mounted?
linux ext4
linux ext4
asked 28 mins ago
Eric Texley
162
asked 28 mins ago
Eric Texley
162
asked 28 mins ago
Eric Texley
162
asked 28 mins ago
Eric Texley
162
asked 28 mins ago
Eric Texley
162
162
add a comment |
add a comment |
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