[SunRescue] Software raid

[Gregory Leblanc]

On 24 Mar 2001 00:11:08 -0500, Joshua D. Boyd wrote:
> Has anyone here ever tried running software raid-5?  I need a new file
> server I guess (my current PeeCee one doesn't have enough drive bays or
> PCI slots).  Sun is an option, but PC is more likely.  

I've run it using the software RAID code in the Linux kernel, and it's
pretty nice.  It's got a ways to go before it's awesome, but it's
reliable, and fairly easy to set up.  

> Anyway, I'm wondering what the possibilities for software raid-5 are.  I
> know the computations are fairly intensive, but would something like a
> dual processor pentium (say dual 166) be able to keep up fast enough to
> saturate 100 mbit? How about an Ultra 1?  Ultra 5?  

Dual P-166 shouldn't have any trouble if it's SCSI, the IDE would
probably kill it though.  Not sure about SPARC machines on doing RAID
calculations, but they should have an easy time about handing the IO.  

> Am I going to find that the cost of a good enough computer will be higher
> than the cost of a hardware solution?

Probably not, and a computer based solution will probably be faster than
a hardware solution for a machine that isn't doing anything else with
it's CPU cycles.  Just remember that you don't do RAID 5 for
performance, or for redundancy, you do it for a bit of redundancy, a bit
of speed on reads, and large storage.  There are other solutions that
are faster, and/or more reliable, but they're not as cheap.

    Greg