Re: databases and RAID ...

On Sat, May 25, 2002 at 12:45:12PM -0700, Fred Moyer wrote:
> Performance (fastest->slowest)
>     hardware raid -> software raid
>     raid 0 -> 10 -> 1 -> 5
> Redundancy (most -> least)
>     hardware raid -> software raid
>     10, 1 -> 5 -> 0

It's really not possible to compare RAID-levels independent from what
the system is beeing used for. E.g. lots of seeks vs continous access,
read-intensive vs write-intensive, how many simultanious accesses and
so on.

E.g. RAID 1 / 10 can easily be as fast, or faster than RAID 0 for read
intensive work.

RAID 5 has a very high penality when doing small writes, but the effect
can be reduced by good RAID-controllers with lots of battery-backed
cached.


For a typical database-application I would agree with your statement
except that RAID 1 is probably faster than RAID 10.


--
Ragnar Kjorstad
Big Storage