I/O hang, possibly XFS, possibly general

[Stan Hoeppner]

On 6/2/2011 9:42 AM, Paul Anderson wrote:

> had mounted the filesystem with inode64,largeio,logbufs=8,noatime.

I don't see 'delaylog' in your mount options nor an external log device
specified.  Delayed logging will dramatically decrease IOPs to the log
device via cleverly discarding duplicate metadata write operations and
other tricks.  Enabling it may solve your problem given your high
metadata workload.  Delayed logging design document:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/filesystems/xfs-delayed-logging-design.txt

Delaylog was an optional mount option from 2.6.35 to 2.6.38.  In 2.6.39
and up it is the default.  Give it a go.

-- 
Stan