Re: replacing a failed RAID component

[Stephen Borrill <netbsd%precedence.co.uk@localhost>]

On Sat, 7 Nov 2009, Steven Bellovin wrote:
> I'm using RAIDFRAME in a RAID 1 configuration.  One of the disks has failed 
> and needs to be replaced; the question is how, precisely, I do it.  More 
> specifically, how do I prepare the new disk?  My assumption is that I have to 
> set up the proper fdisk label (including the boot block); I then have to use 
> disklabel to make the 'e' partition of type RAID.  The last thing I should do 
> is use 'raidctl -R' to reconstruct the RAID set.
>
> Do I need to do anything else?  Do I need to do something to initialize the 
> replacement disk's RAID stuff?

A cheap hack is to use dd to copy the first few sectors (i.e. including 
mbr code, fdisk partition table and diskabel) from one disk to the other.

Then use raidctl -a, raidctl -F, etc. to rebuild the array.
--
Stephen