topic Re: Adding new disks in a DS2300 disk array in Operating System - HP-UX

Adding new disks in a DS2300 disk array

Gousset — Tue, 01 Mar 2005 08:35:43 GMT

The current platform is in a cluster configuration, composed of two servers :
- 1 HP 9000 - rp5470-750/3 - Production server
- 1 HP 9000 - rp5470-750/3 - Stand-by server

Current platform state: 2 DS2300,
VG01 = 8 external disks of 18 Gb, with stripping mechanism at PE level + LVM Mirroring.
REAL available disk space = 4 X 18 Gb due to mirroring.

The situation is that the disk space has to be extended and that it seems that 18 Gb disks are no more available, so we're thinking about adding 2 HDs of 73GB.

Is it possible to have disks with different sizes in a VG with stripping?

What are the drawbacks/consequences ?

Re: Adding new disks in a DS2300 disk array

RAC_1 — Tue, 01 Mar 2005 08:47:58 GMT

while you can add the large capacity disks in vg, there is one possible problem. the max.
no. of PEs are defined at vgcreation time.

man vgcreate for details and check option -e and pe size. Now if you have defined it at the time of creating vg, then no problem, else you will have to re-create the VG with appropriate pe size and appropriate no. of PEs.

Anil

Re: Adding new disks in a DS2300 disk array

Devender Khatana — Wed, 02 Mar 2005 00:19:50 GMT

Hi,

Find out from the output of 'vgdisplay -v /dev/vgxx' of the VGxx you want to extend what is the PV Size and what are the Max PE Supported per Disk.
On multiplying both you will come to know what is the max. space supported per physical disk on your VG vgxx.

You can no doubt have stripping and mirror across two 73GB without any problems. These settings are allready installed at same scenatios without any problems.

HTH,
Devender

Re: Adding new disks in a DS2300 disk array

Devender Khatana — Wed, 02 Mar 2005 00:21:57 GMT

Just a typing mistake -

PE Size* Max PE Per PV = Max Allocatable space per disk

HTH,
Devender