Inexpensive RAID1 card required

[Dave Mason]

Len Sorensen wrote:
> 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.

It's a tiny bit tricky, but what you can do is:

1) create a degraded RAID1 with a single drive of sufficient capacity

2) dd your current partition to the RAID partition

3) resize2fs the new filesystem on the RAID

4) add a partition to the RAID1 and it will start duplicating the data

 (note: you want the RAID partitions on separate IDE/ATA cables or it
 will go *slowly*)

All of the above can be a lot faster than backup/restore.  YMMV.

The software RAID information is at the end of the partition, I believe,
so in theory you might be able to resize your existing partition down a
few blocks, put the RAID information in place, get the RAID drive
recognized, and then resize the partition back to the (now slightly
smaller) size, but the few attempts I've made to do this haven't worked.

../Dave
--
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