2650 setup as an nfs server

lars@levonline.com lars at levonline.com
Thu Jan 23 07:03:00 CST 2003


On Thu, 23 Jan 2003, jason andrade wrote:
> the 2650 has on onboard (ROMB) scsi raid controller built in that might
> be already enabled or that you can buy an enabler kit for, in preference
> to buying an extra card.
>
> performance wise the perc3/QC has been reported to give much better results
> than the perc3/DC but you might also consider software raid.

The onboard SCSI is no good, software raid would give us much better performance.

How much better is the QC than the DC when I use raid 5?

> Can you tell what percentage of that is read and what is write ?  Translating
> those figures roughly gives you 3Mbyte/sec average and 6.5Mbyte/sec peak which
> should easily be possible on the 2650.

Seems like reads and writes are quite even. 

sar output during normal operation:

19:10:00          tps      rtps      wtps   bread/s   bwrtn/s
19:20:00       440.84    214.39    226.45   3297.09   5178.82
19:30:00       237.81    160.09     77.72   2711.86   1737.30
19:40:00       441.91    226.93    214.98   3363.99   4798.88
19:50:00       445.55    221.59    223.97   3195.63   5140.33
20:00:00       236.84    170.95     65.88   2461.72   1864.83
20:10:00       427.93    226.09    201.84   3304.56   4736.98
20:20:00       365.48    149.41    216.07   2109.44   5214.35
20:30:00       155.03     90.35     64.68   1217.33   1371.98
20:40:00       310.91    105.25    205.66   1589.99   4675.30

Am I better of with a DC than a QC with this kind of load under raid5 and only
using the internal diskbays?

regards
/Lars




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