[CentOS] Switching To Raid1

Wed Jan 9 17:44:20 UTC 2008
Dennis McLeod <dmcleod at foranyauto.com>

> -----Original Message-----
> From: centos-bounces at centos.org 
> [mailto:centos-bounces at centos.org] On Behalf Of Matt
> Sent: Wednesday, January 09, 2008 8:55 AM
> To: CentOS mailing list
> Subject: [CentOS] Switching To Raid1
> 
> I have this ASUS M2NBP-VM motherboard 
> http://tinyurl.com/3xby3h running CentOS 4.4 as a web/email 
> server.  It has a 500Gb SATA2 drive with about 32Gb in use.
> 
> The motherboard supports hardware raid.  Is there a way to switch to
> RAID1 without reinstalling or loosing any data?
> 
> Also, if I am running raid how do I know if there is a 
> failure on one of the drives anyway?  Is hardware RAID1 a good idea?
> 
> Matt
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Using a hardware RAID device, you should be able to switch to a mirror,
simply by adding the second drive, and creating a mirror in the bios before
booting up (Be careful in there, though. Make sure you understand what you
see on screen before you commit.)
You SHOULD verify that the OS does see the hardware device before you make
the switch.
(For instance, in windows, put the card in the machine, but don't move the
drive. Boot up, let it detect and install the drivers, then shutdown and
move.)
This MAY or may not work with your ASUS board, though, as it's likely a fake
raid.
I HAVE used some add-in raid cards to make a mirror, and then break it, to
replace a failing drive as well. (A SIIG pci device if I recall)
Not under Centos, though.
As far as getting notified, it will depend on the device. 
I have an Adaptec 2610 raid card under Centos (4) and am able to use a cron
job to send emails with the raid status. I thought is was better to go
hardware when I started this box.

Based on what I've read though, most people here will recommend using a
linux software raid, as they claim the performance is better AND you can get
notification.

Some things I've seen on this list suggests that it CAN be done after the
fact, but the impression is it might be a painful process. I'd us clonezilla
or a h1r3n's boot CD to make an image before I started.....

I'm sure someone more knowing will provide more details.

Here's a blast from the past:

http://lists.centos.org/pipermail/centos/2007-February/076040.html

Let us know what works....

Dennis