[K12OSN] Two SATA mirrors

[Henry Hartley]

Since funds are a little tight I'm tempted to go with your second option - Linux based software RAID. Am I right in assuming that as long as I have enough SATA connecters I should have all the hardware I need for that? I think I need to do a bit more research before I move forward. Do you know of good (and relatively recent) resources explaining how software RAID is done?

--
Henry

From: k12osn-bounces at redhat.com [mailto:k12osn-bounces at redhat.com] On Behalf Of "Terrell Prudé Jr."
Sent: Tuesday, September 08, 2009 1:16 PM
To: Support list for open source software in schools.
Subject: Re: [K12OSN] Two SATA mirrors

Henry Hartley wrote:

I'm building a small server for use at home and I'd like to set it up with mirrored drives (RAID 1). I also thought I might buy two pairs of drives, one small for the "system" and one large for "content". The motherboard I'm looking at is an ASUS M4A78 PRO which says it supports RAID 1 (among others).



I haven't set up RAID before and my question, if anyone happens to know, is whether that means that I can set up two independent pairs of RAID 1 mirrors. That is, I want to mirror two 120GB drives and then mirror a second pair of 1TB drives.



The user manual, which I found on-line, says, "For detailed instructions on how to configure RAID 0, RAID 1, RAID 10, and JBOD, refer to the RAID manual in the support DVD." I can't, however, find the RAID Manual on their web site.



Is what I want to do normally supported? Does anyone have an ASUS motherboard and therefore the support DVD and would be willing to see if anything like this is in the RAID manual (or you could send it to me off-list). Thanks.



Be careful with those "embedded RAID" devices.  Generally they require some Microsoft Windows driver to actually work, so they're really MS-specific software RAID.  It's always mystified me why there's a market for that, because Windows NT Server has supported RAID-1 since v3.50 from 1994.  For this reason, I always steer clear of the "embedded RAID" part and just use those ports like regular ol' SATA ports (aka "JBOD-mode").

If you want to do a couple of mirrors like you're describing, there are better ways to do it.  The first is to get a real RAID card, that is supported by Linux, that doesn't break the bank.  LSI Logic's 150-4 SATA controller (four-port) would be a good fit for you.  I use a couple of their 150-6 SATA controllers with excellent results.

The second way to do it, if you're hesitant about money for the RAID card, is to go ahead and do software RAID, but not with ASUS's controller.  Like Windows NT Server, Linux also supports software RAID directly, and mirroring isn't all that CPU-intensive.

--TP
_______________________________
Do you GNU<http://www.gnu.org>?
Microsoft Free since 2003<http://www.cmosnetworks.com>--the ultimate antivirus protection!

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/k12osn/attachments/20090908/0bc2a402/attachment.htm>