Alan Hodgson schrieb:
Mario Weilguni <mweilguni@xxxxxxxx> wrote:
strange values. An individual drive is capable of delivering 91
MB/sec
sequential read performance, and we get values ~102MB/sec out of a
8-drive RAID5, seems to be ridiculous slow.
What command are you using to test the reads?
Some recommendations to try:
1) /sbin/blockdev --setra 2048 device (where device is the partition or LVM
volume)
2) Use XFS, and make sure your stripe settings match the RAID.
Having said that, 102MB/sec sounds really low for any modern controller with
8 drives, regardless of tuning or filesystem choice.
First, thanks alot for this and all the other answers.
I measured the raw device performance:
dd if=/dev/cciss/c0d0 bs=64k count=100000 of=/dev/null
I get poor performance when all 8 drives are configured as one, large
RAID-5, and slightly poorer performance when configured as JBOD. In
production, we use XFS as FS, but I doubt this has anything to do with
FS tuning.
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