Date: Sat, 14 Jul 2001 00:40:39 +0100 From: Mark Drayton <mark.drayton@izr.com> To: freebsd-questions@freebsd.org Subject: Vinum mirrored/striped confusion Message-ID: <20010714004038.A58799@drex.staff.izr.com>
next in thread | raw e-mail | index | archive | help
Hi
I'm trying to set up a machine with a striped and mirrored set for use
with postfix and cyrus. From vinum(8):
You may want to have the best of both worlds and have both resilience
and performance. This is sometimes called RAID-10 (a combination of
RAID-1 and RAID-0), though again this name is misleading. With vinum
you can do this with the following configuration file:
drive d1 device /dev/da2e
drive d2 device /dev/da3e
drive d3 device /dev/da4e
drive d4 device /dev/da5e
volume raid setupstate
plex org striped 512k
sd length 512m drive d1
sd length 512m drive d2
sd length 512m drive d3
sd length 512m drive d4
plex org striped 512k
sd length 512m drive d4
sd length 512m drive d3
sd length 512m drive d2
sd length 512m drive d1
I don't quite understand why mirroring two plexes containing the same
subdisks is beneficial. What happens if, say, disk 1 fails? I imagine
both plexes will be faulty and the volume will be down which (to me)
almost defies the point of mirroring.
drive d1 device /dev/da2e
drive d2 device /dev/da3e
drive d3 device /dev/da4e
drive d4 device /dev/da5e
volume raid setupstate
plex org striped 512k
sd length 512m drive d1
sd length 512m drive d2
plex org striped 512k
sd length 512m drive d3
sd length 512m drive d4
If disk 1 failed with this setup, will the volume still be up with one
of its plexes in the faulty state?
Aside from this possible difference, is one of these two setups going to
perform better (for a mail server) than the other?
Please point me in the right direction if I need to RTFM!
Cheers,
--
Mark Drayton
izR Company Ltd
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010714004038.A58799>