Snapshots with Shared iscsi Storage

[2000gtacoma]

Is it still not possible to take snapshots with shared iscsi? I was doing some lab testing regarding version 9 and this post below. No matter what I do I get snapshots are not available.

• Snapshots on thick-provisioned LVM storages with snapshots as volume chains (technology preview).A new property on thick-provisioned LVM storages enables support for snapshots as volume chains.With this setting, taking a VM snapshot persists the current virtual disk state under the snapshot's name and starts a new volume based on the snapshot.This enables snapshots on shared thick-provisioned LVM storages, as they are often used on LUNs provided by a storage box via iSCSI/Fibre Channel.Logical volumes for snapshots are currently thick-provisioned, but an underlying storage box may implement thin provisioning.The setting only affects newly created VM disks.VMs currently cannot be migrated if they have snapshots with disks on a local storage that allows snapshots as volume chains.

 

[LnxBil]

If need to activate the chaines snapshots before creating any VM. Existing VMs will not be snapshottable unless they have the correct format.

 

[2000gtacoma]

If need to activate the chaines snapshots before creating any VM. Existing VMs will not be snapshottable unless they have the correct format.

How do I do this? Forgive me I’m very new to proxmox and trying to get my organization to switch as soon as possible far out of the box and beside hyper v proxmox is better imho. I’m still in a lab environment so nothing production yet. Want to iron out as much as possible first.

 

[mir]

It is explained here: https://pve.proxmox.com/pve-docs-9-beta/chapter-pvesm.html#storage_lvm
Simply put, you need to manually add the option in the storage.cfg file yourself. eg:
A LUN exported from a Qnap server

iscsi: qnap
    portal 172.16.2.10
    target iqn.2004-04.com.qnap:ts-212:iscsi.qnap.035443
    content none

lvm: mylvm
    vgname myspace
    base qnap:0.0.0.scsi-36e843b653fc62ced6681d40c2d943cdf
    content images,rootdir
    saferemove 0
    shared 1
    snapshot-as-volume-chain 1

 

[2000gtacoma]

All,

This worked perfectly in my lab. I am now able to complete snapshots over iscsi with lvm.

Thank you!

 

[k6169]

Hello everyone,
Sorry for jumping into this existing thread, but I believe my situation is closely related.
I created a new VM on the LVM storage to test snapshots, but in the GUI the Snapshot button is greyed out and cannot be clicked.
My understanding was that enabling `snapshot-as-volume-chain 1` in the storage configuration should allow VM snapshots on shared storage, but it does not seem to work in my case.

## Question
- Is there any known limitation with FC multipath devices or PureStorage arrays that prevents snapshot-as-volume-chain from working?
- Or am I missing some additional configuration step?
Any advice or confirmation from the community would be greatly appreciated.

## Physical Setup
Servers <FC> SAN Switch <FC> PureStorage FlashArray

## Configuration
/etc/pve/storage.cfg
lvm: PS-LVM-NEW
vgname ps-vg-new
content images
nodes proxmox6
saferemove 0
shared 1
snapshot-as-volume-chain 1

## Command Outputs
root@proxmox6:~# pveversion
pve-manager/9.0.5/9c5600b249dbfd2f (running kernel: 6.14.8-2-pve)
root@proxmox6:~# pvs
PV VG Fmt Attr PSize PFree
/dev/mapper/mpathb ps-vg-new lvm2 a-- 4.10t 4.07t
root@proxmox6:~# multipath -ll
mpathb (3624a9370fd1bc0fc3ecb4aeb000117da) dm-6 PURE,FlashArray
size=4.1T features='1 queue_if_no_path' hwhandler='1 alua' wp=rw
`-+- policy='service-time 0' prio=50 status=active
|- 15:0:0:253 sdc 8:32 active ready running
|- 15:0:1:253 sde 8:64 active ready running
|- 16:0:0:253 sdg 8:96 active ready running
`- 16:0:1:253 sdi 8:128 active ready running
root@proxmox6:~# lsscsi -i
[15:0:0:253] disk PURE FlashArray 8888 /dev/sdc 3624a9370fd1bc0fc3ecb4aeb000117da
[15:0:1:253] disk PURE FlashArray 8888 /dev/sde 3624a9370fd1bc0fc3ecb4aeb000117da
[16:0:0:253] disk PURE FlashArray 8888 /dev/sdg 3624a9370fd1bc0fc3ecb4aeb000117da
[16:0:1:253] disk PURE FlashArray 8888 /dev/sdi 3624a9370fd1bc0fc3ecb4aeb000117da

 

[aderumier]

you need to use qcow2 image format too, and the vm need to have machine version >= 10.

 

[k6169]

>use qcow2 image format
Thank you. I misunderstood that RAW is compatible.