[linux-lvm] Core questions from a LVM neophyte...

[Barry, Christopher]

Greetings all,

	I have built a very cool NAS box, and want to use LVM2 on it. My machine is as follows:

Tyan Thunder i7500 w/ 2-2.4GHz XEON processors.
2GB RAM
3ware Escalade 7500-12 IDE RAID controller
12-160GB Maxtor IDE HDs
System on a separate 20GB Maxtor HD
Floppy, slimline CDROM, and a DVDRW drive.
All in a 12-bay chassis from http://www.rackmountpro.com/productpage.cfm?prodid=1460

This config gives me 1.8TB of RAID 5 for under $8K - not too shabby.

The box is up and running Debian. I compiled 2.4.19, adding in the device-mapper patch, and the latest xfs patch.

My questions are as follows:

In the kernel config, in the RAID section I checked the LVM option to be in the kernel. Is this correct? It seems that I'm getting LVM version 1. Do/should I select this if I've patched the kernel?

I try 'pvcreate /dev/sda' and get an error saying the device is not found. However, 'fdisk /dev/sda' shows the device exists.

Should I use pvcreate directly on the raw RAID 5 device, or partition it first?

My plan was to use LVM2 to create several logical volumes on a single RAID 5 device that I could adjust for size over time and create a snapshot volume to extract backups from. Is this a good idea? I mean is this a good use of LVM2, or not?


Sorry if these questions are really basic, and thanks to all of you for any assistance you can throw my way.

Cheers,


--
Christopher Barry
Manager of Information Systems
InfiniCon Systems
http://www.infiniconsys.com