[SOLVED] Help understanding lvm on iSCSI

[Pigi_102]

Hello all,
I can't really understand how this stuff works ( but it does ).
I have an iSCSI lun presented to my three nodes.
I've created a storage of type iSCSI, then an lvm on top of it.
Pve cluster has correctly configured all this acress the three nodes.
I'v created a couple of vm disks on it and everything is fine.
I can see the disks from webui, my vm are running but on the pve nodes there is not a mount about this.
I think then that is not using a filesystem on it, but how does it works ?
Any link or pointer is fine for me, I'm the RTFM kind of guy, only I cannot find anything around.

Thanks in advance.
Pierluigi

 

[bbgeek17]

I can see the disks from webui, my vm are running but on the pve nodes there is not a mount about this.
I think then that is not using a filesystem on it, but how does it works ?
Any link or pointer is fine for me, I'm the RTFM kind of guy, only I cannot find anything around.

Hi @Pigi_102 ,

LVM is not a filesystem; it is a volume manager. The logical volumes it creates are exposed as raw block devices. The volume is attached to the VM as a virtual disk, and the filesystem is created and managed inside the VM. Because of this, you will not see any mounts on the hypervisor for those volumes.

It is technically possible to mount an LVM volume on the hypervisor if a filesystem was created on it inside the VM. However, you must be very careful about concurrent access. If you need to do this, shut down the VM first, mount the volume on the host, and make sure to unmount it before starting the VM again.

Here is an article that may be helpful:
https://kb.blockbridge.com/technote/proxmox-lvm-shared-storage/

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