topic Re: Do I need to partition LUNs before placing them in LVM in Operating System - Linux

Do I need to partition LUNs before placing them in LVM

Ming Zhao — Wed, 07 Dec 2005 23:25:42 GMT

Hi,

Based on serviceguar Linux manual, looks I need to use fdisk to partition shared LUNs (for example, EVA LUNs) and set type to 8e before placing them in LVM. Is that true? Can I just placing LUNs device name such as /dev/sda in pvcreate command?

Thanks,

Ming

Re: Do I need to partition LUNs before placing them in LVM

Florian Heigl (new acc) — Wed, 07 Dec 2005 23:35:05 GMT

You could use fdisk to set a base partition type so that to LUNs will never by mistake accessed i.e. during an OS install.
If HP recommends it, it's reasonable to follow that recommendation out of support concerns.

Otherwise pvcreate /dev/rsda should do just fine in my opinion.

(Note I used rsda here, at least in my HP-UX environment pvcreate wants a raw device opposed to vgcreate, etc., I think I remember it was the same on linux.)

Re: Do I need to partition LUNs before placing them in LVM

melvyn burnard — Thu, 08 Dec 2005 06:49:49 GMT

To use it correctly in Serviceguard, you need to do the fdisk on the lun's first

Re: Do I need to partition LUNs before placing them in LVM

Sivakumar TS — Thu, 08 Dec 2005 08:16:48 GMT

the LUNs need to be created first.

Re: Do I need to partition LUNs before placing them in LVM

Ivan Ferreira — Thu, 08 Dec 2005 08:32:04 GMT

Yes, it's true, you need to partition the disk, set the partition type, and then run the pvcreate command.

You cannot use /dev/sda, you need to use a partition. You can create just one primary partition and use pvcreate /dev/sda1.

Re: Do I need to partition LUNs before placing them in LVM

Ming Zhao — Thu, 08 Dec 2005 09:05:19 GMT

Thanks to all.

After checking LVM how-to, I think for LVM1, we need to use fdisk, but for LVM2, it is not necessary. But this LVM how-to just cover LVM on Linux, not on Serviceguard/LX, so I still not sure if I need to partition LUNs on Serviceguard/LX.

Thanks,

Ming

Re: Do I need to partition LUNs before placing them in LVM

John Bigg — Thu, 08 Dec 2005 10:43:42 GMT

It it's required by LVM1 then it's required by Serviceguard/LX. Therefore it's required.