Steve,
Many thanks for the reply. I know how difficult it is to keep
track of all support requests! (+ I've only got back from
2 weeks leave so am in no position to complain!)
I'm looking into developing a script that uses 'find' to identify
individual files that are candidates to defrag and that have not
recently changed (& are therefore not likely to be currently
active) and then run 'xfs_fsr' on the individual files, my guess
is that this should then be reasonably safe to run on an active
filesystem?
Anyway hope that you're gettting some well earned holiday next week!
Looking forwards to hearing from you when you/your colleagues
have some time.
Ian Hardy
Quoting Stephen Lord <lord@xxxxxxx>:
> On Wed, 2002-06-26 at 12:36, Ian D. Hardy wrote:
>
> Sorry, you dropped through the cracks there, and I am currently
> sitting in the back of a talk at the Ottawa Linux Symposium, so
> my coding time is a little limited this week. Next week there
> will also be no one in the office (except the Australian
> contingent).
>
> Seems you have two issues, first file fragmentation and the
> fact that fsr appears to have issues on a live system. Yes
> I agree that running fsr during down time is the best solution
> available right now. I do not know if you have an idle time
> where you could actually run fsr on a known idle system. I
> think it has options to run for a fixed amount of time
> instead of running to completion. If you have known times
> when activity is low you could possibly run fsr during this
> period.
>
> The fundamental issue is the amount of memory which one of
> these fragmented files needs to hold its extents and the
> ideal solution to to change how this memory is organized.
> I have tinkered with the idea, but it is a non-trivial
> project and I do not know when I might get to do it.
>
> So I don't really have a code solution for you right now,
> we need to look into what is happening to fsr under nfs
> load, there should be something we can do to fix that
> faster than the extent allocation code.
>
> Steve
>
> > Steve ++ Colleagues,
> >
> > Sorry to bother you (I understand that your busy & short
> > staffed) - it would be useful to get some feedback on
> > the problems/issues I raised a couple of weeks ago (I did
> > note that you mentioned continuing problems due to
> > fragmentation in another thread a few days ago). Do you
> > have any idea if/when it should be possible to fix this
> > problem? (I feel bad asking; but I'm getting preasure to
> > look again at alternatives ...... which I'd rather not do - as I'm
> > sure they have their own problems!).
> >
> > FYI: in the last ~20 days we've had another panic, that looked
> > like another memory alloc error (I was on leave - so didn't
> > get the full details) + a couple of system lockups (high
> > load average and failing to fileserve); possibly not related.
> > We reduced the load by introducing another server/filesystem
> > (reiserfs !!) and moving some users onto that, today we had some
> > scheduled maintenance time and did an ofline defrag of the
> > XFS filesystem bringing it down from ~28% to <1%.
> >
> > Is there anything that I can do (remember I'm not a kernel
> > writer/expert) to help, any further diagnostics that would
> > help.
> >
> > Again many thanks for your help.
> >
> > Ian Hardy
> >
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