 | | | PERC 4 performance | PERC 4 performance 2004-04-07 - By Herman Sheremetyev
Back
Hi All,
My apologies for the cross-post. I just installed Redhat EL 3 ES on a
Dell PowerEdge 2650 with a PERC 4/DC card (LSI PCI RAID controller) and
the performance seems no better than when I tried the PERC3 (Adaptec
onboard RAID controller). I 've played around with stripe size and other
various options while creating the arrays and I can 't seem to get any
noticeable performance boost. My best so far is about 22M/sec for
reading and around 20M/sec for writing, this is with 128K stripe size
and IO set to Cached. These are pretty sad numbers to get from a top of
the line RAID controller and 5 10K RPM SCSI drives in RAID5. In
comparison my laptop gets about 30M/sec reading speeds with 5400K RPM
IDE drive, and my 3ware IDE RAID controller performs even better on a
couple 7200K RPM drives in RAID1. I 've tried both the megaraid and
megaraid2 driver with no large difference between the two.
The tests I 've tried are somewhat primitive, I 've tried hdparm -t and
"cat /dev/sda > /dev/null " while running "vmstat 1 ". Should I try some
other method to test this? Any advice from anybody using these LSI RAID
cards on what kind of performance I should be expecting? The
performance with software RAID on the same drives blows this card way
which seems very wrong to me.
TIA,
-Herman
--
Taroon-list mailing list
Taroon-list@(protected)
http://www.redhat.com/mailman/listinfo/taroon-list
|
|
|