On Tue, Jul 30, 2013 at 09:37:15PM +0200, Stefan Priebe wrote: > Am 27.07.2013 03:50, schrieb Dave Chinner: > >On Fri, Jul 26, 2013 at 08:17:21PM +0200, Stefan Priebe wrote: > >>Hi, > >> > >>what is the right way to use fstrim on top of XFS? just doing fstrim > >>-v -m 4194304 / > >> > >>results sometimes (might depend on disk i/o) to hanging tasks and > >>stack traces - fstrim needs > 5 min in these cases. > > > >It does indeed depend on disk IO. XFS walks all the free space and > >issues discards on it, so runtime is always O(freespace). And while > >it is walking an AG discarding the free space, it will hold the AG > >locked so that free space doesn't change. This can hang other > >operations for the length of time it takes to discard all the free > >space in the AG. > > IOWs, the behaviour of fstrim on XFS is entirely dependent on the > > speed of the block layer and hardware implementations of discards. > > Yes OK i understand that but is there any way to prevent getting the > whole server crash when I/O is too much? Sorry, what crash are you talking about? IO being slow because you ran fstrim isn't a crash.... > For example splitting whole disk or even AGs into subparts? Or set a > timeout for the fstrim command? You can split fstrim up into smaller sections yourself by using the range parameters. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
