[Gluster-users] Performance

[Joe Landman]

On 04/20/2011 05:43 PM, paul simpson wrote:
> many thanks for sharing guys.  an informative read indeed!
>
> i've 4x dells - each running 12 drives on PERC 600.  was dissapointed to
> hear they're so bad!  we never got round to doing intensive tests this
> in depth.  12x2T WD RE4 (sata) is giving me ~600Mb/s write on the bare
> filesystem.  joe, does that tally with your expectations for 12 SATA
> drives running RAID6?  (i'd put more faith in your gut reaction than our
> last tests...)  ;)

Hmmm ... I always put faith in the measurements ...

Ok, 600MB/s for 12 drives seems low, but they are WD drives (which is 
another long subject for us).

This means you are getting about 60 MB/s per drive write on the bare 
file system on drives that are at least (in theory) able to get (nearly) 
double that.

This is in line with what I expect from these units, towards the higher 
end of the range (was this direct or cached IO BTW).  Most of our 
customers never see more than about 300-450 MB/s out of their PERCs with 
direct IO (actual performance measurement).

-- 
Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics Inc.
email: landman at scalableinformatics.com
web  : http://scalableinformatics.com
        http://scalableinformatics.com/sicluster
phone: +1 734 786 8423 x121
fax  : +1 866 888 3112
cell : +1 734 612 4615