Inexpensive RAID1 card required

[Lennart Sorensen]

On Fri, Feb 08, 2008 at 01:25:36PM -0500, Teddy Mills wrote:
> There are a number of servers I have, that do not have RAID installed.
> I cannot easily add mdadm, and create a software RAID on these various servers. (many distros etc.)
> 
> I was wondering if there was a inexpensive Linux RAID1 card.
> I dont want the RAID card to be another SPOF.
> That is, if the RAID1 fails;
> I can just connect either of the RAID1 drives back in to the SATA or IDE connectors on the motherboard.

Hardware raid cards simply don't work that way.  It would really suck if
they did (since then you would loose the raid data if you moved the
drives to a different card of the same type).  They have to store meta
data and disk IDs somewhere, so some space on the disks is needed, which
means your existing data layour doesn't work for hardware raid, or
software raid for that matter.

> And most definitely, I do not want to "reformat" any of my servers to make a RAID1.
> (This would create reliance on the RAID card, and that is what I am trying to avoid)

Then you don't want hardware raid.

> I would hope the Rcard would work as a RAID1 with as little modification as possible.

Switching to raid does require redoing the partition table layout to do
raid, and then adding the filesystem on top of the raid if using
software, and who even knows how a hardware raid card decides to handle
the disks.  I have never seen a raid system that didn't require backing
up everything and reinstalling it to get raid.

--
Len Sorensen
--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists