SUMMARY: Re: detaching a mirror from a trans device -- safe?

From: Adam and Christine Levin (levins@westnet.com)
Date: Fri Oct 27 2000 - 14:22:36 CDT


Thanks to Michael Sullivan <mps@discomsys.com> and Darren Dunham
<ddunham@taos.com>. Both agreed that unmounting the file system first is
the best way to go. Since that's possible, that's what I plan to do. It
would probably be OK to sync and then detach, but I want to be 100% safe,
and these file systems are solely for use by the app, so once the app is
shut down, those file systems will be quiescent. The unmount adds some
piece-of-mind, and will potentially avoid some fsck complaints later.

Thanks,
-Adam

On Fri, 27 Oct 2000, Adam and Christine Levin wrote:
> Ok, I've got what I hope is an interesting question.
>
> We're using a multiple-mirror scheme to backup some sensitive data. The
> way we're doing it is like so:
>
> disk1 <-> disk2 are mirrored
> disk3 is attached to that mirror.
> disk4 is an additional disk.
>
> Every week, we detach disk3 and attach disk4. At any given time, we have
> a two-way mirror (disks 1&2), a third mirror piece that's only missing
> during the resync, and a fourth disk that's got a snapshot of the files.
>
> The question is this: we're using a trans device to take advantage of UFS
> logging (this is all DiskSuite 4.1 under Solaris 2.6, fully
> patched). We've got several small slices on various disks that are
> mirrored together to be the logging piece.
>
> Once I know the filesystem is quiescent (application has been fully shut
> down), can I just detach the third mirror piece? Should I unmount the
> filesystem, detach the mirror, and then remount the filesystem, just to be
> extra sure?
>
> Thanks,
> -Adam
>
>
>

S
U BEFORE POSTING please READ the FAQ located at
N ftp://ftp.cs.toronto.edu/pub/jdd/sun-managers/faq
. and the list POLICY statement located at
M ftp://ftp.cs.toronto.edu/pub/jdd/sun-managers/policy
A To submit questions/summaries to this list send your email message to:
N sun-managers@sunmanagers.ececs.uc.edu
A To unsubscribe from this list please send an email message to:
G majordomo@sunmanagers.ececs.uc.edu
E and in the BODY type:
R unsubscribe sun-managers
S Or
. unsubscribe sun-managers original@subscription.address
L To view an archive of this list please visit:
I http://www.latech.edu/sunman.html
S
T



This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:14:20 CDT