ext4 and data consistency
Posted May 22, 2010 19:15 UTC (Sat) by anton
In reply to: ext4 and data consistency
Parent article: The Next3 filesystem
What bothers me is how they reduced the guarantees and
stability of the long mature ext3 filesystem in the aftermath of all
this, by defaulting it to data=writeback, a change from the old
Yes, that's what was at the back of my mind when I wrote about
"backporting the data loss feature from ext4 to ext3".
Presumably you used tun2fs or simply fstab to ensure your
ext3 mounts remain stable with data=ordered after the kernel in
question (was it 2.6.30 or 2.6.31?), right?
The youngest kernel we have is 2.6.30, and according to /proc/mounts
it mounts our ext3 file systems with data=ordered. I guess we will go
the fstab route once we get a kernel that defaults to data=writeback.
I am a little worried, though, because of what happened after
data=journal was no longer the default; I then read that using
data=journal resulted in corrupt file systems; I read that for a
significant amount of time, and never read that this bug has been
fixed (but haven't seen such reports for some time).
So if they made data=ordered non-default in 2.6.31 or some kernel,
will they really care if it works? My confidence is limited. We
should probably better stick with 2.6.30 until we migrate off extx file
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