kernel: XFS (dm-7): xlog_space_left: head behind tail

[Dave Chinner]

On Wed, Mar 21, 2012 at 05:00:02PM +1300, Gregory Machin wrote:
> I have a CentOS 6.2 virtual machine in a vmware ESXi 4.0 host 4G Ram 4
> virtaul cpus and with about 4 TB of disk space formatted with XFS .
> I'm seeing a lot of :
> 
> Mar 21 10:49:42 nzhmlfpr05 kernel: XFS (dm-4): xlog_space_left: head behind tail
> Mar 21 10:49:42 nzhmlfpr05 kernel:  tail_cycle = 129, tail_bytes = 20163072
> Mar 21 10:49:42 nzhmlfpr05 kernel:  GH   cycle = 129, GH   bytes = 20162880
> Mar 21 10:49:42 nzhmlfpr05 kernel: XFS (dm-7): xlog_space_left: head behind tail
> Mar 21 10:49:42 nzhmlfpr05 kernel:  tail_cycle = 5, tail_bytes = 333417984
> Mar 21 10:49:42 nzhmlfpr05 kernel:  GH   cycle = 5, GH   bytes = 333417792
> Mar 21 10:49:42 nzhmlfpr05 kernel: XFS (dm-7): xlog_space_left: head behind tail
> Mar 21 10:49:42 nzhmlfpr05 kernel:  tail_cycle = 5, tail_bytes = 333417984
> Mar 21 10:49:42 nzhmlfpr05 kernel:  GH   cycle = 5, GH   bytes = 333417792

can you send the complete set of output, including the first
occurrence of it?

What workload are you running? Are you freezing you filesystem
frequently?

> What would casue this ? A quick google , I found a post that indicated
> I should unmount and mount the file systems. I have live production
> data on this machine so I need to be careful. What is the best
> solution ?

Best solution? I don't know enough about the problem yet to suggest
one.

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com