Steve Bergman steve@rueb.com wrote:
Good points as to the advantages of software RAID. This machine is fully certified by RedHat, but the CERC 6ch controller is uncertain,
The CERC 6ch uses the aaraid driver. Administrative tools are largely lacking though.
It's also an old Intel i960-based design, so it's rather sluggish. At RAID-5 its so-so, the i960 is a bit of a bottleneck with today's drives. But at RAID-0, 1 or 10, the i960 will be a massive bottleneck.
so software RAID seems the right choice.
The question is, how are you going to do software RAID? Are you going to use the AIC-7xxx SCSI channels on the CERC 6ch?
If that does bypass the sluggish i960, then it would probably be faster at RAID-5 and far, far faster at RAID-0, 1 or 10. But if you have to put the i960 in JBOD mode, the i960 still might be a bottleneck to the SCSI channels.
Which means you're not going to see any better performance, so you might want to just use the i960 hardware RAID.
[ SIDE NOTE: This is why I don't like generalized RAID discussions. How to do RAID is a question of what hardware you have -- for _both_ software or hardware. ]