[Gluster-devel] seeking advice: how to upgrade from 1.3.0pre4 to tla patch628?

[Amar S. Tumballi]

>
> 2) Is there a significant speed benefit to having fewer? (other than
> file creation I mean)  All out tests used dd and single files so we
> didn't notice much.
>

Actually AFR creates files in serial order. Hence, create time over
glusterfs very much depends on the number of subvolumes AFR has. This will
hold good for symlink() and mknod() also.



> -Mic
>
> Sascha Ottolski wrote:
> > Am Dienstag 08 Januar 2008 10:06:33 schrieb Anand Avati:
> >
> >> Sascha,
> >>  few points -
> >>
> >> 1. do you really want 4 copies of the NS with AFR? I personally think
> that
> >> is an overkill. 2 should be sufficient.
> >>
> >
> > at least that would give us the freedom to take any server out without
> having
> > to think about. however, we also tried with only one namespace and no
> afr,
> > same bad result :-( (with 1.3.2)
> >
> >
> >
> >> 2. as you rightly mentioned, it might be the self heal which is slowing
> >> down. Do you have directories with a LOT of files in the immediate
> level?
> >>
> >
> > not do many: we have nested 6 directories, only the leafs carry files.
> each
> > directory level can have up to 16 sub-directories. in the leaf, up to
> 255 * N
> > files with 0 < X < 4, with X most likely being near 2.
> >
> > that is, at max. 256 * 4 = 1024 files per dir.
> >
> >
> >
> >> the self-heal is being heavily reworked to be more memory and cpu
> efficient
> >> and will be completed very soon. If you do have a LOT of files in a
> >> directory (not subdirs), then, it would help to recreate the NS offline
> and
> >> slip it in with the upgraded glusterfs. one half-efficient way:
> >>
> >> on each server:
> >> mkdir /partial-ns-tmp
> >> (cd /data/export/dir ; find . -type d) | (cd /partial-ns-tmp ; xargs
> mkdir
> >> -p)
> >> (cd /data/export/dir ; find . -type f) | (cd /partial-ns-tmp; xargs
> touch)
> >>
> >> now tar the /partial-ns-tmp on each server and extract them over each
> other
> >> in the name server. I assume you do not have special fifo and device
> files,
> >> if you do, recreate them like the mkdir too :)
> >>
> >
> > thanks for the hint. still, in an earlier attempt, we forced a self heal
> and
> > waited until it was finished after 24 h, but even then was the load
> staying
> > high, the webservers almost not responding (as said above, with only one
> > namespace brick).
> >
> >
> >
> >> the updated self-heal should handle such cases much better (assuming
> your
> >> problem is LOTS of files in the same dir and/or LOTS of such dirs).
> >>
> >
> > can't wait to test it :-))
> >
> >
> > Thanks a lot,
> >
> > Sascha
> >
> >
> > _______________________________________________
> > Gluster-devel mailing list
> > Gluster-devel at nongnu.org
> > http://lists.nongnu.org/mailman/listinfo/gluster-devel
> >
>
>
> --
>
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-- 
Amar Tumballi
Gluster/GlusterFS Hacker
[bulde on #gluster/irc.gnu.org]
http://www.zresearch.com - Commoditizing Supercomputing and Superstorage!