[CS-FSLUG] RAID vs. rsync?

[Karl Kleinpaste]

Timothy Butler <tbutler at ofb.biz> writes:
> I'm debating about setting up a system using software RAID1 or finding
> something like rsync (would rsync work?) to keep two disks in sync.

I used RAID1 on a number of systems for some years.  It's effective,
it's simple to administer, and it has interesting performance
characteristics.  "Write twice + read either" can be very cool but you
need to have the 2 discs on separate channels in order to get any
performance benefit.

> If going the RAID route, anyone have experience setting up a software
> RAID in Linux *after* Linux is already installed on the primary disk?

It's a bit dated, but this is still out there:
http://www.faqs.org/docs/Linux-mini/Boot+Root+Raid+LILO.html

You'll want to use grub these days, and you may need to set it up
manually so as to have both discs able to boot.