Ocfs2 users - Oct 2011 - enabling discontig-bg

We upgraded from 1.4 to 1.6 to avoid some FS fragmentation issues (the 
"No space left on device" error, but the FS is not full yet). But it 
looks like we really need to enable discontig-bg to take advantage of 
that. Our file systems have these attributes:

Compat: backup-super
Incompat: None
RO Compat: None

Do we really need to enable discontig-bg in order to avoid the 
fragmentation problem?

If so, do I need to unmount the FS on all nodes in order to enable the 
feature? (offline operation)

-- 
Florin Andrei
http://florin.myip.org/

On 10/14/2011 12:23 PM, Florin Andrei wrote:
> We upgraded from 1.4 to 1.6 to avoid some FS fragmentation issues (the
> "No space left on device" error, but the FS is not full yet). But
it
> looks like we really need to enable discontig-bg to take advantage of
> that. Our file systems have these attributes:
>
> Compat: backup-super
> Incompat: None
> RO Compat: None
>
> Do we really need to enable discontig-bg in order to avoid the
> fragmentation problem?
Yes, you won't avoid fragmentation by enabling this feature. It now 
allows ocfs2 filesystem system files to grow in smaller contiguous
chunks.
> If so, do I need to unmount the FS on all nodes in order to enable the
> feature? (offline operation)
yes