Return to BSD News archive
Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!ihnp4.ucsd.edu!dog.ee.lbl.gov!agate!asami
From: asami@freebsd.org (Satoshi Asami)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: ccd question on mirroring
Date: 17 Oct 1996 07:28:21 GMT
Organization: CS Div. - EECS, The University of California, Berkeley, CA 94720
Lines: 39
Message-ID: <ASAMI.96Oct17002821@sunrise.cs.berkeley.edu>
References: <chad-1210962031330001@sverige.pengar.com>
NNTP-Posting-Host: sunrise.cs.berkeley.edu
In-reply-to: chad@pengar.com's message of Sat, 12 Oct 1996 20:31:33 -0600
In article <chad-1210962031330001@sverige.pengar.com>
chad@pengar.com (Chad Leigh) writes:
* ccd0 0 MIRROR_FLAG /dev/sd1e /dev/sd2e
*
* where MIRROR_FLAG is whatever the man pages said it should be
CCDF_MIRROR
* The config failed and the machine kept rebooting itself. (My console is
* monitor is usually plugged into a different computer and the FreeBSD
* machine is headless most of the time. I pligged it in long enough to see
* it was rebooting itself and that som "ahci_XXX_YYY nore more datagrams" or
* something similar [message from late last night from memory] was happening
* and it kept trying to sync() the disks and failing and restarting.
The problem is that the mirroring code is actually handled as part of
striping. I may have forgetten to check if the interleave is 0.
* I booted up under a different kernel and went in and changed the ccdconfig
* line to
*
* ccd0 32 MIRROR_FLAG /dev/sd1e /dev/sd2e
*
* and upon rebooting it seems to be working fine.
*
* I find it strange that it required an interleave factor when I really want
* the 2 disks mirrored and not striped. ccd0 does show up as one disk the
* size of the IBM drive.
Yes, this should work.
To make it truly mirrored without any striping effects, you can make
the interleave size ridiculously large, that way one write request
will always generate two writes to the disks and never more than that. :)
I'll look into it.
Satoshi