Poor read performance on Dell Perc H200 RAID10 with (4) 1TB 7200rpm 64MB drives

delldell-perchardware-raidraid

I am seeing only 50MB/s reads:

ensnare@box:~$ sudo hdparm -tT /dev/sda
[sudo] password for ensnare:

/dev/sda:
 Timing cached reads:   4592 MB in  2.00 seconds = 2296.48 MB/sec
 Timing buffered disk reads:  192 MB in  3.90 seconds =  49.24 MB/sec

The array is already rebuilt and operational. Is this kind of slow performance normal? Anything I can do to make it faster? There weren't too many options in the controller configuration. Thanks.

Best Answer

The short answer is yes, that's the level of performance you should expect to see from the H200.

The long answer: The H200 is the old SAS 6iR with SATA 6Gb/s support. It doesn't have the usual features you'd see on a RAID card (battery backup unit, onboard caching, RAID5/6 support). The cache determines how fast your RAID array is (along w/ the # of spindles and type of drive), so no cache = slow performance. Add the 7200RPM SATA drives (which are slow compared to a 10-15k RPM SAS drive) and that's the level of performance you can expect.

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