Subject Re: [IB-Architect] Disk Bandwidth was License Question
Author Jim Starkey
At 11:40 AM 3/26/00 +1000, you wrote:
>From: "Jan Mikkelsen" <janm@...>
>From: Jim Starkey <jas@...>
>>The way to use multiple disks is not placement control but striping
>>so that successive page reads automatically go to a device not
>>in use. Well, duh. And maybe, just maybe, Linux will figure this
>>out someday.
>There is a RAID kit for Linux which supports striping, mirroring and RAID-5
>in software. It isn't perfect (mirroring doesn't do proper read balancing,
>for example), but the work is being done. We've been using various versions
>for about 18 months.

Good. Excellent things, RAIDs. But golly, machines are so fast
and cheap now, wouldn't it be nice to move the intelligence to
the OS for a lower cost high performance solution? Smart disk
controllers are always going to have a tighter integration with
the drivers and will probably always be the high end solution.
But striping and mirroring can (quote in theory unquote) be done
by the host OS. Sure would be nice. On the other hand, the big
win in controller based mirroring is the ability to direct a read
to a drive not in use or a drive with the arm on the target track
is a screamer.

Jim Starkey