Re: [Gluster-devel] Full bore.

[Chris Johnson]

On Fri, 16 Nov 2007, Anand Avati wrote:

     Very simple iozone call

     iozone -aN -r 32k -s 131072k

Now what I probably should be doing is testing this against the actual
load, the real image processing code to be used.  Did look at io
caching.  That would possibly help if a number of jobs on the cluster 
were to crunch the same file at the same time.  If that were not the
case I'm not sure what io caching would give me.

     The config?  You can't get much simpler than this, maybe by
pulling the read-ahead and write-behind which weren't there
originally.

volume brick1
  type storage/posix
  option directory /home/sdm1
end-volume

volume server
  type protocol/server
  subvolumes brick1
  option transport-type tcp/server     # For TCP/IP transport
#  option client-volume-filename /etc/glusterfs/glusterfs-client.vol
  option auth.ip.brick1.allow *
end-volume

volume writebehind
  type performance/write-behind
  option aggregate-size 131072 # in bytes
  subvolumes brick1
end-volume

volume readahead
  type performance/read-ahead
  option page-size 65536 ### in bytes
  option page-count 16 ### memory cache size is page-count x page-size per file
  subvolumes brick1 
end-volume

> >       Performance is still way below NFS.  I have turned on
> > write-behind and read-ahead.  And with fuse it's a little faster. but
> > not significantly.
>
>
> What is your IO pattern? what are the tests you are running? what is your
> interconnect? NFS can provide really good re-read performance which you can
> get out of glusterfs using io-cache on the client side.
>
>      Can we have a discussion on whether I'm heading in the right
> > direction and what order things go in for the config files?
>
>
> Can you paste your config files on pastebin and link it and also tell us the
> kind of application/IOtests you are running?
>
> thanks,
> avati
>
>
> --
> It always takes longer than you expect, even when you take into account
> Hofstadter's Law.
>
> -- Hofstadter's Law

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