Description of problem: For creating ext3 filesystem, When "blockscount" option is less than 2048, mke2fs will create a ext2 filesystem It looks like an ext3 filesystem issue, we can't know the details reason of ext3/mke2fs, So if we can do nothing in libguestfs, it would be better to add a note to the documentation Version-Release number of selected component (if applicable): libguestfs-1.22.6-4.el7.x86_64 How reproducible: Always Steps to Reproduce: # guestfish -N fs mke2fs /dev/sda1 fstype:ext3 blockscount:2048 : list-filesystems /dev/sda1: ext3 # guestfish -N fs mke2fs /dev/sda1 fstype:ext3 blockscount:2049 : list-filesystems /dev/sda1: ext3 # guestfish -N fs mke2fs /dev/sda1 fstype:ext3 blockscount:2047 : list-filesystems /dev/sda1: ext2 Actual results: Output is ext2 when fstype:ext3 blockscount:2047 Expected results: Output should be ext3 when fstype:ext3 blockscount:2047 Additional info: Has same issue in rhel6, libguestfs-1.20.10-3.el6.x86_64
As discussed on IRC, the problem is that the filesystem isn't large enough to contain a journal. mke2fs prints the warning message: Filesystem too small for a journal This message is normally eaten by libguestfs, although you can see it if you enable debugging. The warning doesn't stop mke2fs; it goes ahead and creates a filesystem without a journal, a.k.a. ext2. Anyway, we should document that this may happen. BTW don't confuse "blockscount" (size of the filesystem in blocks) with block size.
https://github.com/libguestfs/libguestfs/commit/1c8986e45c3f1a7e2391bde2848667332495e3aa
Fix also included in libguestfs-1.20.10-4.el6 (note there is no separate bug for RHEL 6, I just included the fix in the routine build).
Verified with libguestfs-1.22.6-16.el7.x86_64 ><fs> help mke2fs DESCRIPTION "mke2fs" is used to create an ext2, ext3, or ext4 filesystem on "device". The optional "blockscount" is the size of the filesystem in blocks. If omitted it defaults to the size of "device". Note if the filesystem is too small to contain a journal, "mke2fs" will silently create an ext2 filesystem instead. Help out is update
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