Needed: best practices when updating server that has shared storage in cluster

[psalet]

Hi All,

I am looking for the "best practice" for upgrading a server in a cluster (22 systems) that is sharing it's iscsi mounts to the rest of the cluster.

I am about to take on the task of upgrading the memory on one of my main servers that is the focal point for the connection to the iscsi storage. I am really concerned that it would take down all of the VMs in the cluster as the storage is being shared from that server.

Give me some ideas.
Thanks
--paul

 

[VictorSTS]

If all your storage is in a single iSCSI box, you have a single point of failure, which kinda defeats the whole purpose of a cluster.

You will need to plan for downtime, stop everything on PVE, log out iSCSI from each PVE (not sure if needed, but I would do it), stop the iSCSI storage, update memory, start iSCSI storage, reconnect iSCSI on all PVE, start the VMs. Also, I would run memtest on those sticks before using them on the production system, just in case (although they might break during installation on the production server).

If you have some other storage that you may use, you could do live storage migration so VM's can run from it while you upgrade that ram.

 

[psalet]

I went with the one host sharing the iscsi was to make the migrating be only moving the /etc/pve/qemu-server/conf file to the destination server. So then my question would be "If I mount the iscsi drive on each server this will fix this issue." I just need to keep the iscsi naming the same name on all servers.
I just want to make sure when migrating VMs from one server to another that I am not copying any data files just the conf file.
Hope that made sense.
--paul,