CCD Raid-1 Setup on OpenBSD 4.1

IMNOboist · 06-01-2007, 12:54 PM

I'm running OpenBSD 4.1 and trying to get CCD setup on my two hard drives. I want them to mirror in realtime. I have one drive setup with two partitions; one BSD and one swap. I need to mirror the BSD partition onto the other drive, which is currently uninitialized.

My problem is that documentation on this subject is rather lacking. Would someone be able to step me through this? Here's what I know so far:

Drives: wd0 and wd1
wd0 Partition: wd0a
wd1 Partition: none

Here's a df output:
Filesystem 512-blocks Used Avail Capacity Mounted on
/dev/wd0a 443772708 5230236 416353840 1% /

If you need any more info, I'd be glad to give it.

Thanks!

frob23 · 06-01-2007, 03:36 PM

http://inglorion.net/documents/tutorials/ccd/

Here is one for OpenBSD. Please note that there is no practical way to use ccd to mirror the root partition. So your above partitioning scheme is not going to work at all. We can use the empty disk to fix this by putting everything on it and then redoing both disks... but that is going to take some work and an understanding of the tools required to do it.

First, are the disks the same size?

If they are, then it will be a lot easier. If not... that is okay also.

I assume these are both 250G [on box] disks (with 212G actually) so I will recommend a partitioning scheme like the following:

Code:

/     :: 250M   (non-ccd on each disk)
swap  :: 1G     (on each disk)
/tmp  :: 500M   (if you use it a lot you will need to increase this)
# The following should be created under ccd -- you may not want to keep /tmp
# under ccd because there is nothing important to keep on it
/var  :: 1G     (size depends on usage expectations this should be ample)
/usr  :: 3G     (or the remaining amount if you keep /home under this)
/home :: 206G   (or whatever remains)

Now: setting this up... that is the tricky part. You will want to do a complete dump to a safe location before starting this... the partitions we will be using for ccd are not safe. If you can burn it to a dvd, that would work... or if you have another computer over the network... you can dump across the network (with ssh) and the install kernel should have the tools to restore it over ssh.

Anyway... go read that page... to get a basic idea of what needs to be done and if you have any specific questions I will try and help. this is going to be more than a simple procedure.