Date: Sun, 26 Aug 2001 10:08:35 +0930 From: Greg Lehey <grog@FreeBSD.org> To: scanner@jurai.net Cc: Odhiambo Washington <wash@wananchi.com>, Mario Doria <mariodoria@yahoo.com>, FBSD-Q <freebsd-questions@FreeBSD.ORG> Subject: Re: Setup VINUM Message-ID: <20010826100835.J21776@wantadilla.lemis.com> In-Reply-To: <Pine.BSF.4.21.0108241350110.77542-100000@sasami.jurai.net>; from scanner@jurai.net on Fri, Aug 24, 2001 at 01:50:47PM -0400 References: <20010824175750.D84710@ns2.wananchi.com> <Pine.BSF.4.21.0108241350110.77542-100000@sasami.jurai.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On Friday, 24 August 2001 at 13:50:47 -0400, scanner@jurai.net wrote: > On Fri, 24 Aug 2001, Odhiambo Washington wrote: > >> * Mario Doria <mariodoria@yahoo.com> [20010824 17:37]: writing on the subject 'Setup VINUM' >>> Hi, >>> >>> I'm planning on setting up a machine with four disks working on RAID 1 (one >>> pair of 9GB drives and one pair of 40GB drives). I want to use vinum but first >>> I want to have a pretty good grasp about it, so, please if you know about a >>> tutorial, can you please send it to me? > > Yes. Use mine at http://www.jurai.net/~scanner/vinum-howto.html There are a number of misleading statements in this tutorial. For example, the entire section on labelling with sysinstall is a waste of time: it's completely unnecessary. It also claims that Vinum wants special indentation, which is just plain not true, though I tend to indent like that in the examples. The most important inaccuracy is the claim that the stripe size should be exactly 256 kB. That's wrong: use one a little larger, as described in the man page: For optimum performance, stripes should be at least 128 kB in size: anything smaller will re- sult in a significant increase in I/O activity due to mapping of individual requests over multiple disks. The performance improvement due to the increased number of concurrent transfers caused by this mapping will not make up for the performance drop due to the increase in latency. A good guideline for stripe size is be- tween 256 kB and 512 kB. Avoid powers of 2, however: they tend to cause all superblocks to be placed on the first subdisk. I've been meaning to read this document and send some suggestions back to you, but I just haven't had time. It has some good stuff in it, but it really needs to be read in conjunction with the man pages. Basically, you can't compress all the info about Vinum into a couple of hundred lines. You need to understand the principles, and this tutorial doesn't help with that. Greg -- See complete headers for address and phone numbers 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?20010826100835.J21776>