Re: Adding a mirror to a RAID1 Device

["H. Peter Anvin" <hpa@zytor.com>]

Followup to:  <16323.732.390200.935640@notabene.cse.unsw.edu.au>
By author:    Neil Brown <neilb@cse.unsw.edu.au>
In newsgroup: linux.dev.raid
> 
> What you should have done is make a raid1 with 2 drives, one of which
> was missing/failed.  With mdadm, the command would be:
> 
>   mdadm -C /dev/md0 --level=raid1 --disks=2 /dev/hda3 missing
> 
> then you can hot-add the extra drive when it arrives.
> 
> What you have to do now is recreate the raid1 with two drives.  You
> will have to have the filesystem unmounted and the raid stopped, but
> you will not lose any data.
> 

For the case of RAID-1 in particular, it would be nice to be able to
hotadd drives "ad infinitum"... after all they're all the same.

	-hpa
-- 
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
If you send me mail in HTML format I will assume it's spam.
"Unix gives you enough rope to shoot yourself in the foot."
Architectures needed: ia64 m68k mips64 ppc ppc64 s390 s390x sh v850 x86-64