Configuring for faster read/write performance
I've got an HP DL580-G2 (W2K Adv Server SP4) with dual 2Gb/s SAN adapters connected to a dual RAIDed MSA1000 with 2/8 SAN switches incorporated at the back. (20*140GB 10K rpm disks in RAID-0+1).
I want to read and write 500MB files as quickly as possible and I've set it up pretty much out of the box -- just a FCAL loop I think. What suggestions do you have to get the max out of this configuration?
You will get the fastest performance by using RAID-0 although you will not be able to survive a drive failure with that RAID
type. Your use of RAID-0+1 is probably the better approach. Depending on the number of disks in the array, the controllers in the MSA 1000 default to ADG (advanced data guard), so make sure ADG is disabled.
The MSA1000 install guide states that for best performance when using RAID0+1, it is best to stripe ACROSS buses. From the manual: "For example, because drive bays 1-7 in the MSA1000 are located on bus 1 and bays 8-14 are located on bus 2, when creating a mirrored array with six drives, include the drives in bays 1, 2, 3 and 8, 9, 10."
One other thing you could do is to use a volume manager on the server to create a volume that includes LUN
s from multiple RAID groups
. Doing so will allow you to spread the I/O load across as many spindles as possible, from multiple shelves if you have them.
The views and opinions expressed by Christopher L. Poelker are his alone and not necessarily shared by Hitachi Data Systems.
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This was first published in April 2004