[CentOS] Some basic LVM questions

[Monte Milanuk]

M. Hamzah Khan wrote:
> There won't be any issue in doing this. The installer just tries to make
> things easier by creating one big volume group.
>
> I'd say that in some ways seperating the two disks in this case would
> actually be better. :)
>   
My last 'serious' experience with Linux was some years ago... mostly 
before LVM really became popular (it was out and about, but mostly only 
in SuSE).  I'm still 'stuck' in the mind set of a main drive or 
partition for things like '/', possibly even /boot, /var, /usr, etc. and 
then keeping /home separate - mainly so the user data in /home survives 
upgrades and updates and such ;)
> With both drives in one big volume group, failure of one drive will
> (most likely) cause both the OS and data to be lost. 
>   
There in lies some of my confusion with this subject; correct me if I'm 
wrong in my understanding here: with LVM, I can keep adding more drives 
to a 'pool' and expand the size of the 'volume' that the OS sees 
available to it... but if any drive in that volume fails, I'd probably 
lose everything stored in that volume?!?  Sounds like a somewhat risky 
business to me, unless you *really* needed a storage volume that big 
that you had to span multiple drives to do so.

> Seperating them will mean that if your OS drive fails you can replace
> the dead drive, reinstall CentOS (or restore from a backup), and your
> data will be accessible again.
>   
Kind of what I had in mind, as the 13GB drive is much older (circa 2005, 
if its the original one put in when the previous owner built the box 
from a bare-bones kit) than the 500GB SATA drive (earlier this year, 
when I stuck it in there) so if I had to put money on one failing before 
the other... ;)