shared virtual disk on vms

[remzi akyuz]

Hi,

can i use shared disks in vms? Is it possible?

I want to use this disk in 2 vms.

virtio1: depo0:8201/vm-8201-disk-3.qcow2,size=2G
virtio2: depo0:8201/vm-8201-disk-2.qcow2,size=2G

How can i share they ?

Thanks.


root@proxmox:~# qm config 8201
agent: 1
balloon: 2048
bootdisk: ide0
cores: 4
hotplug: memory,cpu,network,disk,usb
ide0: depo0:8100/base-8100-disk-1.raw/8201/vm-8201-disk-1.qcow2,cache=writeback,size=64G
memory: 8704
name: w2k12cls1
net0: virtio=66:65:38:63:32:65,bridge=vmbr0
net1: virtio=66:37:66:34:38:39,bridge=vmbr1
numa: 1
ostype: win8
scsihw: virtio-scsi-pci
smbios1: uuid=ad84ea64-d9ce-4152-a4e0-02be1ec31807
sockets: 1
vcpus: 2
vga: cirrus
virtio1: depo0:8201/vm-8201-disk-3.qcow2,size=2G
virtio2: depo0:8201/vm-8201-disk-2.qcow2,size=2G
root@proxmox:~#

root@proxmox:~# qm config 8202
agent: 1
balloon: 2048
bootdisk: ide0
cores: 4
hotplug: memory,cpu,network,disk,usb
ide0: depo0:8100/base-8100-disk-1.raw/8202/vm-8202-disk-1.qcow2,cache=writeback,size=64G
memory: 8704
name: w2k12cls2
net0: virtio=32:61:63:36:61:39,bridge=vmbr0
net1: virtio=66:61:63:64:63:39,bridge=vmbr1
numa: 1
ostype: win8
scsihw: virtio-scsi-pci
smbios1: uuid=73f21ed5-f1bd-4bf3-b063-d330f5a0ddd3
sockets: 1
vcpus: 2
vga: cirrus

 

[JonathanB19]

One way would be to set up an NFS server VM and have client machines connect to the exports.

 

[remzi akyuz]

Thanks for your information.
But it is not enough for us. Because of cluster files system requires shared disk.

 

[JonathanB19]

OK, well I've not tried it, but you could try simply editing the VM's config files so that they use the same disk image (eg both using vm-8201-disk-1.qcow2 for ide0).

You can't do that from the GUI though - you'll have to edit the VM's configs directly in /etc/pve/nodes/proxmox/qemu-server/

Whether this actually works may depend on the guest though - I might try it myself on my test machine as I'm curious to see what might happen.

 

[fireon]

GlusterFS can to this for you. We have done this with PVE3.X. Is a time ago.

 

[remzi akyuz]

Hi JonathanB19 and fireon,
Thanks for yours advices.

I can use Glusterfs/iscsi or like them, but this solution take more resources.

Proxmox <<-->> iscsi server(freenas/openfiler) VM under proxmox <<-->>MS windows iscsi client1
<<-->>MS windows iscsi client2
I dont like edit config file by the hand.

I will try centos qemu-kvm solution. May be centos qemu-kvm usefully this time.

 

[JonathanB19]

Good luck remzi! You've inspired me to experiment with the same thing - would be very useful to share disks between vms.

 

[leouni]

Hi,

I'm testing sharing virtual disks between VMs to deploy an ocfs2 cluster.

I have Proxmox with an LVM shared storage.

I've modified configuration file by hand, simply copying the lines for disks configuration and disabling cache.

This works fine but I experienced an issue with migrating the VMs; infact with a two nodes proxmox cluster and with a VM with disks shared for each node, if I force live migration of VM1 from node 1 to node 2 the migration process succeded and task status is OK, but the way if I want to put back VM1 to node 1 the migratioin process completed but the task status is ERROR.

The failure is in deactivating LVs, I think because Proxmox try to deactivate LVs even if the same LVs are currently used by VM2.

Logs:
May 17 09:38:19 migration status: completed
can't deactivate LV '/dev/LVM_PROXOMOX_1/vm-1010-disk-4': Logical volume LVM_PROXOMOX_1/vm-1010-disk-4 in use.
can't deactivate LV '/dev/LVM_PROXOMOX_1/vm-1010-disk-2': Logical volume LVM_PROXOMOX_1/vm-1010-disk-2 in use.
can't deactivate LV '/dev/LVM_PROXOMOX_1/vm-1010-disk-3': Logical volume LVM_PROXOMOX_1/vm-1010-disk-3 in use.
can't deactivate LV '/dev/LVM_PROXOMOX_1/vm-1010-disk-5': Logical volume LVM_PROXOMOX_1/vm-1010-disk-5 in use.
May 17 09:38:47 ERROR: volume deativation failed: LVM_proxmox_1:vm-1010-disk-4 LVM_proxmox_1:vm-1010-disk-2 LVM_proxmox_1:vm-1010-disk-3 LVM_proxmox_1:vm-1010-disk-5 at /usr/share/perl5/PVE/Storage.pm line 932.
May 17 09:38:52 ERROR: migration finished with problems (duration 00:01:30)
TASK ERROR: migration problems

Confs:

VM1
bootdisk: virtio0
cores: 4
ide2: zfs_iso_temp:iso/V100082-01.iso,media=cdrom
memory: 4096
name: mailserver1.1
net0: virtio=66:35:32:37:38:64,bridge=vmbr2,tag=67
numa: 0
ostype: l26
smbios1: uuid=fb5680ee-c49c-4e8e-a3c7-b63d507a38b2
sockets: 1
virtio0: LVM_proxmox_1:vm-1010-disk-1,size=8G
virtio1: LVM_proxmox_1:vm-1010-disk-2,cache=none,size=8G
virtio2: LVM_proxmox_1:vm-1010-disk-3,cache=none,size=8G
virtio3: LVM_proxmox_1:vm-1010-disk-4,cache=none,size=8G
virtio4: LVM_proxmox_1:vm-1010-disk-5,cache=none,size=8G


VM2
bootdisk: virtio0
cores: 4
ide2: zfs_iso_temp:iso/V100082-01.iso,media=cdrom
memory: 4096
name: mailserver1.2
net0: virtio=36:65:30:31:31:39,bridge=vmbr2,tag=67
numa: 0
ostype: l26
smbios1: uuid=f5f9bbea-54a5-4ae6-8115-dda742479b5c
sockets: 1
virtio0: LVM_proxmox_1:vm-1011-disk-1,size=8G
virtio1: LVM_proxmox_1:vm-1010-disk-2,cache=none,size=8G
virtio2: LVM_proxmox_1:vm-1010-disk-3,cache=none,size=8G
virtio3: LVM_proxmox_1:vm-1010-disk-4,cache=none,size=8G
virtio4: LVM_proxmox_1:vm-1010-disk-5,cache=none,size=8G