topic Re: Initialize H/w raid devices for LVM in Operating System - Linux

Initialize H/w raid devices for LVM

arkie — Tue, 23 Feb 2010 12:45:55 GMT

Hi,

In one rx2660 with 8 x 300GB disks and Smart Array P400 RAID Controller, we have created one 300GB RAID1 volume (for the OS) and a second RAID5 volume with the remaining 6 disks. After installing RHEL 5.2 we are getting two device files, viz., /dev/cciss/c0d0 and /dev/cciss/c0d1.

All the root partitions have been created on /dev/cciss/c0d0. Now, we want to assign the whole of /dev/cciss/c0d1 as a DATA VOLUME GROUP

`pvcreate` is not working on /dev/cciss/c0d1

Can anyone pls guide

Thanks!

Re: Initialize H/w raid devices for LVM

Steven E. Protter — Tue, 23 Feb 2010 14:41:14 GMT

Shalom,

The P400 storage controller presents disks to the OS. The OS does not see the disks that comprise the RAID configuration. It just sees the two disks.

Please post output of this command:
fdisk -l

SEP

Re: Initialize H/w raid devices for LVM

Matti_Kurkela — Tue, 23 Feb 2010 16:36:25 GMT

If you run "pvcreate /dev/cciss/c0d1", what is the error message?

Have you read the man page for pvcreate? If the disk has been used before, the partition table on the disk must be erased first. The command to do that is given in the DESCRIPTION chapter of the man page.

MK

Re: Initialize H/w raid devices for LVM

arkie — Wed, 24 Feb 2010 11:04:46 GMT

`fdisk -l` is listing the device /dev/cciss/c0d1 - which is a Raid5 device done thru a P-400 Smart Array Controller.

But when we try to initialize it with:-

`pvcreate -f /dev/cciss/c0d1`

we are getting the following error:-

Device /dev/cciss/c0d1 not found (or ignored by filtering)

Re: Initialize H/w raid devices for LVM

Matti_Kurkela — Wed, 24 Feb 2010 14:49:41 GMT

> Device /dev/cciss/c0d1 not found (or ignored by filtering)

If "fdisk -l" can see the device and reports the correct size for it, the device is obviously there.

That leaves the second part of the message: "(or ignored by filtering)". This refers to the filter expression in /etc/lvm/lvm.conf.

Run "grep filter /etc/lvm/lvm.conf". You should get a lot of comments and at least one uncommented filter expression.

The default filter expression is usually

filter = [ "a/.*/" ]

which allows all disk devices.
Your system seems to use a more strict filter expression. You may need to modify it to allow /dev/cciss/c0d1 too.

MK