🚀 go-pugleaf

Please keep in mind that only RAID Levels 0 through 5 are standardized.
Neither RAID 6 nor RAID 7 are standardized in any way. I have a Mylex
RAID at home which claims to be switchable to RAID 0,1,5,6 and 7.
They define RAID 6 as mixture of striping and mirroring, and RAID 7 as 
just a buch of disks (JBOD). While StorComps approach to RAID had a
couple of advantages, it is - to my mind - an implementation of a RAID
4, improved by large caches, thus trying to eliminate the bottle neck of
a single parity drive. Async transfers from the cache to the parity drive or
from the cache to the data drives have some disadvantages - for example
in a power fail situation. StorComp's RAID relies heavily on such async
transfers. You really need an uninterruptible power supply if you think
of using this disk array. At the moment I am evaluating RAID
implementations for a German unix magazine. I have had Storcomp's RAID
at home and think it performs nicely as long as there are enough hot
standby drives available. If a drive fails and if there is no hot
standby, performance will drop dramatically. There are a couple of
advantages the Storcomp RAID offers, but to my mind it is just a vendor
specific implementation of RAID 4 (it need not be bad just because it is
RAID 4).


Thomas Weihrich
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Thomas Weihrich
Thomas.Weihrich@arbi.Informatik.Uni-Oldenburg.DE

Thomas.Weihrich@WWWA.ORG < this is a perfectly valid email address :)

#include <std_disclaimer.h>

	> We had joy, we had fun, we had PACMAN for the SUN ... <
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