Re: Software RAID5 with 2.6.0-test
From: Pavel Machek
Date: Thu Oct 23 2003 - 03:17:08 EST
Hi!
> Now that I'm posting anyway - I thought of a plus for the HW RAID
> controllers (hey, they're way behind on the scoreboard so far, so I
> might as well be a gentleman and give them a point or two):
> *) Battery backed write cache
>
> This will allow the controller to say 'ok I'm done with your sync()',
> way before the data actually reaches the disk platters. For some
Well, this would mean not only battery-backed controller,
but battery-backed drives, too. (Unless you want to assume that
memory-backup-battery never goes empty).
> While on that topic: SDRAM PCI cards with battery backup can be had
> relatively cheap up to at least a few gigabytes. It'd be pretty cool to
> have the kernel recognize that for buffer storage. I could see the fun
> in doing half a million random writes and a sync(), and having the
> system tell me it's done the microsecond I issue the sync().
Sync would still take some time as it still makes sense to
do writeback... Main memory is still faster than PCI.
Pavel
--
Pavel
Written on sharp zaurus, because my Velo1 broke. If you have Velo you don't need...
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/