At 11:27 30-1-2003 -0500, Greg Freemyer wrote:
Or have any thoughts about a pure software Raid?
I like software raid, good value for the price. It's fast too.
I know the md driver can do Raid 1, can it do Raid 5?
Yes, for the best performance you should at least use the version 2
log(journal) with a md raid5 or even better, use a external logdevice.
A raid 1 system disk would be a good candidate. Note that putting the
external logdevice on a different drive _can_ result in a performance
bottleneck when you have more concurrent metadata throughput (not data!)
then the external logdevice can shove.
My suggestion, put 2 15K rpm scsi disks in a raid 1 config (may be software
raid) for the root and boot drive and put the external logdevice on here as
well. Then use the rest of the disks for a software raid 5 container with
about 4-5 disks per scsi channel (if you use scsi).
The faster logdevice disks can do a lot of IO per second which will help a
busy filesystem.
If 3ware does deliver cards for IA64 the external log device issue is moot.
Cheers
--
Seth
It might just be your lucky day, if you only knew.
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