Okay so, here’s a fun question that I haven’t quite wrapped my head around and unfortunately haven’t had a chance to experiment with. Assuming a CSI volume is registered and set to single-node-writer. I use the
volume stanza in the group block to pull in this CSI volume. Suppose I have 2 tasks in said group (which will get allocated to the same client because group); can I give each task a
volume_mount stanza that uses the CSI volume? Of course one would be set to
read_only = true so as to honor the whole single writer aspect of the CSI volume.
The reason I ask is that so far we’ve been having good fun with CSI, but we also have recently gotten word that we need to do something more on the backups front (even though our provider makes backups already, but regulatory hilarity… etc. etc.). And we can’t just stop the job, remount the volume elsewhere to pull a backup, and then restart the job so the idea was to sidecar a little script in a container that just sits there and once every 24 hours kicks off an rsync/borg/whatever to our backup store. For which it only needs read-only ability.
And the documentation unfortunately isn’t very clear on what can and can’t be done with different access modes at the moment