On 25/06/2025 at 09:50, Trupti wrote:
On 2025-06-23 20:58, Trupti wrote:
To complete the end-to-end test scenario, I am now creating test files
on the Bookworm partitions.
I will proceed with the Trixie installation, manually preserving the
partitions, and will then verify the files are intact in the new
system. I will post the final results of this data integrity test here
soon.
(...)
You were absolutely right — I’ve completed the testing as suggested.
I tested ext4 (4K & 64K) and Btrfs partitions between Bookworm (64K
kernel) and Trixie (4K kernel), and the following behavior was observed:
1]ext4 partitions with 4K block size worked fine — existing files were
accessible without issues.
2]ext4 (64K) and Btrfs partitions couldn’t be mounted in Trixie
(showed a "Mount Failed" error),
and the installer failed unless those partitions were formatted.
ext4 with a 4K block size is compatible across both kernels. However,
partitions created with a 64K block size (ext4 or Btrfs) are not
supported by the 4K kernel. These need to be formatted during
installation, which can lead to potential data loss.
To sum it up:
- With bookworm d-i and installed system 64k page size kernel,
mkfs.btrfs with default options and mke2fs -T largefile|largefile4
create filesystems with 64k block size.
- With trixie d-i 4k page size kernel, btrfs and ext* with 64k block
size filesystems are not supported and cannot be reused without being
reformatted with 4k block size (and losing data).
Shouldn't it at least be mentioned in ppc64el installation manual ?