Red Hat Bugzilla – Bug 1002032
mke2fs can't return the correct filesystem type when blockscount is less than 2048 for ext3
Last modified: 2014-06-17 22:01:16 EDT
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):
Steps to Reproduce:
# guestfish -N fs mke2fs /dev/sda1 fstype:ext3 blockscount:2048 : list-filesystems
# guestfish -N fs mke2fs /dev/sda1 fstype:ext3 blockscount:2049 : list-filesystems
# guestfish -N fs mke2fs /dev/sda1 fstype:ext3 blockscount:2047 : list-filesystems
Output is ext2 when fstype:ext3 blockscount:2047
Output should be ext3 when fstype:ext3 blockscount:2047
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.
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
"mke2fs" is used to create an ext2, ext3, or ext4 filesystem on
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
Help out is update
This request was resolved in Red Hat Enterprise Linux 7.0.
Contact your manager or support representative in case you have further questions about the request.