[linux-lvm] Misleading documentation (was: HDD Failure)
slamb at slamb.org
Tue Sep 19 22:40:43 UTC 2006
On Sep 18, 2006, at 12:37 PM, Mark Krenz wrote:
> LVM != RAID
> You should have been doing RAID if you wanted to be able to
> handle the
> failure of one drive.
This is my biggest beef with LVM - why doesn't *any* of the
documentation point this out? There are very few good reasons to use
LVM without RAID, and "ignorance" certainly isn't among them. I don't
see any mention of RAID or disk failures in the manual pages or in
For example, the recipes chapter  of the HOWTO shows a non-trivial
setup with four volume groups split across seven physical drives.
There's no mention of RAID. This is a ridiculously bad idea - if
*any* of those seven drives are lost, at least one volume group will
fail. In some cases, more than one. This document should be showing
best practices, and it's instead showing how to throw away your data.
The "lvcreate" manual page is pretty bad, too. It mentions the
ability to tune stripe size, which on casual read, might suggest that
it uses real RAID. Instead, I think this is just RAID-0.
 - http://tldp.org/HOWTO/LVM-HOWTO/recipeadddisk.html
Scott Lamb <http://www.slamb.org/>
More information about the linux-lvm