[kwlug-disc] Hardware raid vs linux

[unsolicited]

john at netdirect.ca wrote, On 08/20/2009 8:31 PM:
> The downside in choosing Linux over the cheap RAID 
> card is that if the primary disk fails the system may fail to boot from 
> the secondary disk? The BIOS on a cheap RAID card should do that work, 
> but with Linux there isn't a reliable option.

This is why you not infrequently find 2 drives mirrored for the OS, 
and 3+ drives RAIDed for the data. Seems a little insidious, I know, 
but the other advantage it brings is you can bring up a second system, 
physically move the RAID only, and get on with your day a little 
faster. (Cause, also typically, at a time of failure people frequently 
take the opportunity to apply patches, upgrade the OS, and so on and 
so forth. By the separation, testing of the 'new' system is slightly 
less destructive. If you don't, the act of trying an update on the 1st 
partition of a RAID, say, and it goes bad ... - oops deleted the wrong 
partition ...)

This layout is also not atypical of racked systems, with fibre 
channel. (iSCSI?)