LVM and RAID1

[Aleksandar Milivojevic]

Mark wrote:
> Hi,
> 
> I read the intro to LVM and like the fact that I can add additional HDs without problems.
> However, if I want to have everything running in a RAID1 configuration in case one of my hard disks decides to crash or break some
> sectors, how do the two work together?
> Do I first configure the RAID1 and put the LVMs on top of my md_ partitions?
> 
> How reliable is this, and how much performance do I loose?

I find it very reliable.  I've heard some people having trouble under 
heavy loads, but I beleive thay also had some other exotic stuff changed 
in Kernel (non-standard memory page size and stuff like that).

Anyhow, to configure it, first create RAID1 md device, as usual (say you 
created /dev/md4).  Than define it as physical volume (pvcreate 
/dev/md4) and simply add it into existing volume group (vgextend 
vol_group /dev/md4), or use it as component of new volume group 
(vgcreate new_vol_group /dev/md4).

-- 
Aleksandar Milivojevic <amilivojevic at pbl.ca>    Pollard Banknote Limited
Systems Administrator                           1499 Buffalo Place
Tel: (204) 474-2323 ext 276                     Winnipeg, MB  R3T 1L7