[linux-lvm] Adding a disk to expand an existing logical volume

[Stuart D. Gathman]

On Wed, 19 May 2010, kevin wrote:

> a disk to logical volumes? I want to ensure that the existing data on the
> logical volume isn't compromised and have never done this before.
> 
> If theres something I should be aware of or if my process is incorrect,
> please let me know. Any help is extremely appreciated J 

While others have given you the procedure, I'll be the killjoy and point
out that the reliability of the VG as a whole goes down with additional
drives - unless you incorporate some kind of RAID.  For instance, if the
uptime ratio of a single drive is .99999 (5 sigmas), the uptime
of the system with two such drives is .99998.  

This is not so bad with just 2 drives (even 2 sigmas gives you .99^2 == .98),
but is something to keep in mind before adding the 3rd.   I prefer software
RAID1, it provides a lot of flexibility including "cloning" a drive by simply
removing it and is simple.  Other configurations will provide better
performance.

-- 
	      Stuart D. Gathman <stuart at bmsi.com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.