1 Oct 2009 01:23
Re: PERC 320/DC in Precision 650 with RHEL5; Pitiful Disk Performance
J. Epperson <Dell <at> epperson.homelinux.net>
2009-09-30 23:23:01 GMT
2009-09-30 23:23:01 GMT
On Wed, September 30, 2009 18:55, Charles Knox wrote: > Hi all, For reasons of application compatibility I have recently upgraded > a Precision 650 from RedHat 9 (which it shipped with) to RHEL5. The disk > system in this machine is four 143GB SCSI drives as a RAID5 set on the > PERC320/DC Adaptec built controller. Before the update, the performance > of the RAID was sort-of OK, no great shakes but I suspect it would do > Read/Write operation at about 40MB/sec. Since the update performance has > taken a BIG hit. At first I could get only about 3 MB/sec on the RAID > with the load on the system going up into the over 12 regime. A web > search on the aacraid driver plus performance yielded a hit at the SuSE > site having to do with telling the driver to not do write caching with a > modification to /etc/modprobe.conf; adding the line > > options aacraid cache=2 > > I did this, and performance screamed up to 5-6MB/sec, but the load still > skyrocketed when large writes were done. Does anyone have any ideas > about how to speed this up, aside from launching the PERC out the window > and attaching the disks to the LSI controller in the system and trying > software RAID? > Have not touched a 320 in a long time, but IIRC there's a background consistency check option somewhere that if turned on will really bog down a RAID 5. Look for that. _______________________________________________ Linux-PowerEdge mailing list Linux-PowerEdge <at> lists.us.dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge(Continue reading)
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