The table in https://pve.proxmox.com/pve-docs/chapter-pvesm.html states "Shared: no". But the footnote reads:
Effectively I was abble to tick the share option for the LVM volume I created on one of the node. My pb now is to make this LVM storage active on the second node when the first on which I created the LVM volume is off. I made some tests and the 2nde node was not abble to activate this LVM storage. It seems correct as the second node even not have a PV which point to this "shared" storage. So now I'm wondering what are the steps I have to follow to reach my aim which is to have a LVM shared storage which is active on the first node and then switches to the second when the first is in fault.
It seems that it does not work for SAS-based storage: after that I created a LVM-thick storage on node 1, allowing it at he cluster level I find it on node 2 -in the un-activated state). My pb is that I don't see how to activate it on node 2. I understand that a LVM storage can not be activated on two nodes at a time but I have no idea on how to make it activated when node 1 is off.
Actually my nodes are in a cluster which has a total of 3 nodes, the third one being there only for the quorum.
then it will work as advertised
Since your storage is attached to a cluster aware environment, not only you can, but you must. vgchange -ay should do the trick; if it doesnt activate at boot you may need to put that in as a post boot script or service.
Something that I do not totally explain happened: I created a new VM on the 2nd node of my proxomox cluster allocating to this VM a hard-drive on the SAS storage (I just wanted to try and see what would happen) shared between the 2 nodes but only active on the 1rst node at this time. The LVM VG became magically also active on the 2nd node. So right now the shared SAS storage is active on the two nodes. It seems that ticking the shared option on the storage declaration at the cluster level has no effect in a sens or another on the way the sharing works.then it will work as advertised
Its just that it's not a common solution within the proxmox use cases, since sas is only two channels and a min cluster size is three. logically, the system doesn't really differentiate from iscsi and sas as they are both SBP (scsi block protocol.)
Since your storage is attached to a cluster aware environment, not only you can, but you must. vgchange -ay should do the trick; if it doesnt activate at boot you may need to put that in as a post boot script or service.
Regarding LVM on a SAS attached storage between 2 nodes (in a cluster of 3 nodes), as I said I created a VG on node 1 and allowed it for 2 nodes (node 1 and node 2) through the GUI "cluster" menu. At this step the VG was seen on both nodes but active only on node 1 (as it was clearly mentionned in the GUI). This VG became active for both nodes when I tried to create a VM on the node 2 and declared a hard-drive on the shared LVM: it seems that the creation of a LV (the VM hard-drive) on the shared LVM storage activated the VG on node 2. To sumerize it was partially automatic
