Proxmox Storage question

[arunv707]

Hello Guys,

I was planning to implement a HA proxmox cluster with three nodes and a storage box (planning to use iSCSI) as shared storage. I was in search for best practices for doing so. I got many pieces of information from here and there, but still not clear about some. Hope you guys can help me.

1) I think proxmox will be using LVM on the top if iSCSI volume as datastore. If so, is there any option to use qcow2 disks on the top of it.?

2) If the option #1 is not an option, I think we can directtly attach iSCSI volume to hypervisor and specify it as storage backen. In this case we can use qcow2 and get all the benefits of using qcow2? Will the same iSCSI volume can be attached to the all three nodes as storage backend for HA ?

3) if and #1 and #2 are not possible , what is the best shared storage that can be used in production? NFS? What are the drawbacks of NFS as vm disk storage backend?

 

[blackpaw]

Hello Guys,

I was planning to implement a HA proxmox cluster with three nodes and a storage box (planning to use iSCSI) as shared storage. I was in search for best practices for doing so. I got many pieces of information from here and there, but still not clear about some. Hope you guys can help me.

1) I think proxmox will be using LVM on the top if iSCSI volume as datastore. If so, is there any option to use qcow2 disks on the top of it.?

2) If the option #1 is not an option, I think we can directtly attach iSCSI volume to hypervisor and specify it as storage backen. In this case we can use qcow2 and get all the benefits of using qcow2? Will the same iSCSI volume can be attached to the all three nodes as storage backend for HA ?

Unfortunately qcow2 cannot be used with LVM or iSCSI.

3) if and #1 and #2 are not possible , what is the best shared storage that can be used in production? NFS? What are the drawbacks of NFS as vm disk storage backend?

We use here with our three nodes, its quite functional. However random write performance is pretty dreadful with NFS. Samba actually performs better, but you have to setup the storage mounts manually.

 

[arunv707]

Is 2nd option is not possible? Directly attaching same iSCSI volume to all three nodes? We hardware fencing and moreover same vms disk will only be accessed by a single node at a time. In this case we can also use qcow2.

 

[blackpaw]

Is 2nd option is not possible? Directly attaching same iSCSI volume to all three nodes? We hardware fencing and moreover same vms disk will only be accessed by a single node at a time. In this case we can also use qcow2.

iSCSI LUN direct and LVM are both block devices, so you can only use raw format with them - there is no filesystem for a qcow2 file to be placed on.