[Ocfs2-users] Determining which version of ocfs2 tools a filesystem was created with.

[Sunil Mushran]

On 02/07/2011 10:41 PM, Mikey Austin wrote:
> We have been using the ocfs2 tools (version 1.4.4) on gentoo (2.6.18-164.15.1
> kernel) for around 6 months now. We would like to re-create all of the ocfs2
> filesystems that were not created with mkfs.ocfs2 version 1.4.4, however we
> are not able to determine the version of the ocfs2 tools our filesystems were
> created with .
>
> Is this possible with version 1.4.4 of the tools?

The main difference in mkfs.ocfs2 1.4.4 is that it preallocates space
in all extent_alloc system files.

Do:
# debugfs.ocfs2 -R "ls -l //" /dev/sdX1 | grep extent_alloc
     20              -rw-r--r--   1     0     0         8388608 22-Sep-2010 15:49 extent_alloc:0000
     21              -rw-r--r--   1     0     0         8388608 22-Sep-2010 15:49 extent_alloc:0001
     22              -rw-r--r--   1     0     0         8388608 22-Sep-2010 15:49 extent_alloc:0002
     23              -rw-r--r--   1     0     0         8388608 22-Sep-2010 15:49 extent_alloc:0003
     24              -rw-r--r--   1     0     0         8388608 22-Sep-2010 15:49 extent_alloc:0004
     25              -rw-r--r--   1     0     0         8388608 22-Sep-2010 15:49 extent_alloc:0005
     26              -rw-r--r--   1     0     0         8388608 22-Sep-2010 15:49 extent_alloc:0006
     27              -rw-r--r--   1     0     0         8388608 22-Sep-2010 15:49 extent_alloc:0007

The 6th column is size. Here we see all of the extent_allocs were created
8M in size. mkfs prior to 1.4.4 would not have preallocated space. Now do
remember that as this system file is dynamically allocated, a volume
formatted with the older mkfs can also show the same. But lower probability.