[Ocfs2-users] Defragmenting OCFS2

[David]

Ran into an issue last week were a 150GB OCFS2 partition would not allow 
any further data to be written to it.  The issue was first discovered as 
a result of a PHP web app alarming that it couldn't write files to 
disk.  When the issue was investigated initial indications showed; via 
`df -h`, that the partition still had 56GB of space left.  When an an 
attempt to create a random file using dd was performed it ran into the 
same issue.

Realizing that the server is acting as a file server and that a PHP web 
app is processing imports and exports of small files it started looking 
like the OCFS2 fs was fragmented which resulted in unusable disk space 
that appears via `df` to be available.

We have since moved to a much larger partition but realize that without 
knowing the fragmentation "ceiling" that exists with regards to 
writing/deleting small files on this partition we will eventually run 
into the same thing.

First thought was, how can the OCFS2 FS be defragmented, however I 
realize that there might also be some tuning that could be done to 
minimize fragmentation in the first place.  Can anyone help me with 
either of these concepts?

Thanks!
David