Date: Wed, 6 Mar 2002 22:04:45 -0500 From: Brian T.Schellenberger <bts@babbleon.org> To: Cliff Sarginson <csfbsd@raggedclown.net>, questions@FreeBSD.ORG Subject: Re: Softupdates on root in 4.5-RELEASE Message-ID: <20020307030446.19E24BA03@i8k.babbleon.org> In-Reply-To: <20020306145517.GE4280@raggedclown.net> References: <47615415@toto.iv> <20020306144816.C2BBFBA03@i8k.babbleon.org> <20020306145517.GE4280@raggedclown.net>
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On Wednesday 06 March 2002 09:55 am, Cliff Sarginson wrote:
| On Wed, Mar 06, 2002 at 09:48:16AM -0500, Brian T. Schellenberger wrote:
| > On Wednesday 06 March 2002 09:35 am, Cliff Sarginson wrote:
| > | On Wed, Mar 06, 2002 at 03:19:26AM -0600, Mike Meyer wrote:
| > | > I personally make the root partitoin larger, enable soft updates, and
| > | > use SCSI disks with proper tagged queuing support so the write cache
| > | > isn't a problem.
| > |
| > | Can you clarify this a bit.
| > | With a SCSI disk, tagged queuing etc, soft-updates are not helpful ?
| > | yes or no ?
| >
| > No. That is, they ARE helpful.
| >
| > But with tagged queuing on a SCSI disk, write caching isn't dangerous, so
| > there's no reason not to use it.
| >
| > With an IDE disk, write caching IS dangerous.
| >
| > Another advantage of SCSI.
|
| Ok, so currently this BSD system runs off SCSI with soft-updates on
| everything, except root.
|
| Would you recommend that optimal performance would be achieved, without
| danger, by enabling write-caching as well ?
Yes, if you have tagged queuing. Check your messages (dmeg).
| And what would you recommend therefore with root, which has neither
| enabled at the moment ?
Provided it's reasonably large (say, over 100M).
But you can't enable/disable write-caching on a per-partition basis anyway.
--
Brian T. Schellenberger . . . . . . . bts@wnt.sas.com (work)
Brian, the man from Babble-On . . . . bts@babbleon.org (personal)
ME --> http://www.babbleon.org
http://www.eff.org <-- GOOD GUYS --> http://www.programming-freedom.org
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