LVM presented disk SPLIT among VM's

[TAvery]

Not sure if I am trying to do the right approach.

I would like to take the following 2 drives and split them on the host to a couple of VM's for their OS and data drives.

# ioscan -fnNC disk
Class I H/W Path Driver S/W State H/W Type Description
===================================================================
disk 1 64000/0xfa00/0x0 esdisk CLAIMED DEVICE HP IR Volume
/dev/disk/disk1 /dev/disk/disk1_p2 /dev/rdisk/disk1 /dev/rdisk/disk1_p2
/dev/disk/disk1_p1 /dev/disk/disk1_p3 /dev/rdisk/disk1_p1 /dev/rdisk/disk1_p3
disk 13 64000/0xfa00/0x9 esdisk CLAIMED DEVICE DGC AX4-5WDR10
/dev/disk/disk13 /dev/rdisk/disk13
disk 15 64000/0xfa00/0xb esdisk CLAIMED DEVICE DGC AX4-5WDR5
/dev/disk/disk15 /dev/rdisk/disk15
#

Disk 1 is my host and i am not touching it.

disk 13 is my DB drive I would like to split in 3 pieces so that the only thing the EMC iSCSI array knows is its just one allocation.

disk 15 is my OS drive I would like split in 3 pieces as well. It is also iSCSI EMC.

Each of these pieces is going to a new virtual machine.

The cmd line build is as follows:
(i have not run the DB02VM or DB03VM yet)

hpvmcreate -P DB01VM -O HPUX -e 10 -r 10G -a network:avio_lan::vswitch:vs01 -a network:avio_lan::vswitch:vs02 -a disk:avio_stor::disk:/dev/rdisk/disk15 -a disk:avio_stor::disk:/dev/rdisk/disk13

hpvmcreate -P DB02VM -O HPUX -e 10 -r 10G -a network:avio_lan::vswitch:vs01 -a network:avio_lan::vswitch:vs02 -a disk:avio_stor::disk:/dev/rdisk/disk15 -a disk:avio_stor::disk:/dev/rdisk/disk13

hpvmcreate -P DB03VM -O HPUX -e 10 -r 10G -a network:avio_lan::vswitch:vs01 -a network:avio_lan::vswitch:vs02 -a disk:avio_stor::disk:/dev/rdisk/disk15 -a disk:avio_stor::disk:/dev/rdisk/disk13

I think I am missing a piece in there that actually divides up the disk15 and disk 13.

Need a little command line help thanks.

This to me seems like a mess waiting to happen.

Here is an output

# hpvmdevmgmt -l all
# HP Virtual Machine Management Database
# Created 01/30/11 18:36:58 by user root
# Version 4.20.5
#
# This file must not be modified by hand.
#
HPVM MANAGEMENT_DB START
DB01VM:CONFIG=server::WWID_NULL
/etc:CONFIG=rdev,EXIST=YES,DEVTYPE=DIRECTORY,SHARE=NO,RECURSIVE=FS::HPVM_DIR_STATID_4_1073741827
/stand:CONFIG=rdev,EXIST=YES,DEVTYPE=DIRECTORY,SHARE=NO,RECURSIVE=FS::HPVM_DIR_STATID_2_1073741825
/dev/vg00/rlvol1:CONFIG=rdev,EXIST=YES,DEVTYPE=LV,SHARE=NO,AUTORDEV=YES::HPVM_LVOL_TYPE1_0x01.0x00.0x03.0x600508e0000000009178c6e4adc73805$$1$$/dev/vg00/rlvol1
/dev/vg00/rlvol2:CONFIG=rdev,EXIST=YES,DEVTYPE=LV,SHARE=NO,AUTORDEV=YES::HPVM_LVOL_TYPE1_0x01.0x00.0x03.0x600508e0000000009178c6e4adc73805$$2$$/dev/vg00/rlvol2
/dev/vg00/rlvol3:CONFIG=rdev,EXIST=YES,DEVTYPE=LV,SHARE=NO,AUTORDEV=YES::HPVM_LVOL_TYPE1_0x01.0x00.0x03.0x600508e0000000009178c6e4adc73805$$3$$/dev/vg00/rlvol3
/dev/vg00/rlvol4:CONFIG=rdev,EXIST=YES,DEVTYPE=LV,SHARE=NO,AUTORDEV=YES::HPVM_LVOL_TYPE1_0x01.0x00.0x03.0x600508e0000000009178c6e4adc73805$$4$$/dev/vg00/rlvol4
/dev/vg00/rlvol5:CONFIG=rdev,EXIST=YES,DEVTYPE=LV,SHARE=NO,AUTORDEV=YES::HPVM_LVOL_TYPE1_0x01.0x00.0x03.0x600508e0000000009178c6e4adc73805$$5$$/dev/vg00/rlvol5
/dev/vg00/rlvol6:CONFIG=rdev,EXIST=YES,DEVTYPE=LV,SHARE=NO,AUTORDEV=YES::HPVM_LVOL_TYPE1_0x01.0x00.0x03.0x600508e0000000009178c6e4adc73805$$6$$/dev/vg00/rlvol6
/dev/vg00/rlvol7:CONFIG=rdev,EXIST=YES,DEVTYPE=LV,SHARE=NO,AUTORDEV=YES::HPVM_LVOL_TYPE1_0x01.0x00.0x03.0x600508e0000000009178c6e4adc73805$$7$$/dev/vg00/rlvol7
/dev/vg00/rlvol8:CONFIG=rdev,EXIST=YES,DEVTYPE=LV,SHARE=NO,AUTORDEV=YES::HPVM_LVOL_TYPE1_0x01.0x00.0x03.0x600508e0000000009178c6e4adc73805$$8$$/dev/vg00/rlvol8
/dev/rdisk/disk1:CONFIG=rdev,EXIST=YES,DEVTYPE=DISK,SHARE=NO,AUTORDEV=YES::0x01.0x00.0x03.0x600508e0000000009178c6e4adc73805
localnet:CONFIG=gdev,EXIST=YES,DEVTYPE=SWITCH,SHARE=YES::WWID_NULL
lan0:CONFIG=gdev,EXIST=YES,DEVTYPE=NIC,SHARE=NO:vs01:WWID_NULL
vs01:CONFIG=gdev,EXIST=YES,DEVTYPE=SWITCH,SHARE=YES:DB01VM:WWID_NULL
lan1:CONFIG=gdev,EXIST=YES,DEVTYPE=NIC,SHARE=NO:vs02:WWID_NULL
vs02:CONFIG=gdev,EXIST=YES,DEVTYPE=SWITCH,SHARE=YES:DB01VM:WWID_NULL
lan2:CONFIG=gdev,EXIST=YES,DEVTYPE=NIC,SHARE=NO:vs03:WWID_NULL
vs03:CONFIG=gdev,EXIST=YES,DEVTYPE=SWITCH,SHARE=YES::WWID_NULL
/dev/rdisk/disk15:CONFIG=gdev,EXIST=YES,DEVTYPE=DISK,SHARE=NO:DB01VM:0x01.0x00.0x03.0x600601603eb020004e50f1b7d028e011
/dev/pt/pt1:CONFIG=gdev,EXIST=YES,DEVTYPE=DISK,SHARE=NO:DB01VM:0x01.0x00.0x03.0x60060160048020003c7341fc7718e011
HPVM MANAGEMENT_DB EOF
#

Thank you.

[Richard Hepworth · Accepted solution]

Hi,

Your commands above will fail because you cannot allocate the same disk device to multiple VM's (unless they have been marked as SHARE=YES, but this would not suite what you're after anyway).
The best way to split a single disk up between multiple VM's is to create a volume group in LVM with disk13 & 15 and then create 6 logical volumes. You can then allocate these logical volumes as disks to your VM's

The example below will allocate 2 x 20Gb 'disks' to each of your 3 VM's:

pvcreate /dev/rdisk/disk13
pvcreate /dev/rdisk/disk15
vgcreate /dev/vmvg /dev/disk/disk13 /dev/disk/disk15
lvcreate -L 20480 /dev/vmvg (run 6 times)

hpvmcreate -P DB01VM -O HPUX -e 10 -r 10G -a network:avio_lan::vswitch:vs01 -a network:avio_lan::vswitch:vs02 -a disk:avio_stor::lv:/dev/vmvg/rlvol1 -a disk:avio_stor::lv:/dev/vmvg/rlvol2

hpvmcreate -P DB02VM -O HPUX -e 10 -r 10G -a network:avio_lan::vswitch:vs01 -a network:avio_lan::vswitch:vs02 -a disk:avio_stor::lv:/dev/vmvg/rlvol3 -a disk:avio_stor::lv:/dev/vmvg/rlvol4

hpvmcreate -P DB03VM -O HPUX -e 10 -r 10G -a network:avio_lan::vswitch:vs01 -a network:avio_lan::vswitch:vs02 -a disk:avio_stor::lv:/dev/vmvg/rlvol5 -a disk:avio_stor::lv:/dev/vmvg/rlvol6

You will get better IO performance on your VM's using whole disks rather than LV's but if you only have 2 disks to play with between your VM's then this is probably your best choice.

regards,

Richard

[TAvery]

Thanks for the help with the command line.


We have decided to delete all the drives and not try to split the iscsi presentations rather carve out drives individually on the EMC Array. If we have to move between blades with a VM that would seem an easier alternative.

[Emil Velez]

Logical volumes work very well as disks for integrity VM. That way you allocate your disks in appropriate luns to the volume group and then create logical volumes based on the size of the boot disk that a VM needs.

IF you use LVs for Vms you cannot present the same LV acrosss multiple systems for migration. That is the only limitation.

IF you were not going to use migration (online or offline) LVM or vxvm provides you flexability to define the sizes of disks to be any size you need.

The shared device should only be used for disks between VMs that are for volume groups of a serviceguard package either between VMs on the same host or vms on different hosts.