u/Darkblood18

I'm having a problem where suddenly all my instances (all run some flavor of Ubuntu) have their filesystems go Read Only. It happens randomly and at least once it happened with nothing really running on the VMs.

Looking at one of the Compute/Storage nodes, I noticed a broken iSCSI connection. I run "dmesg -T" and got something like:

[Fri Aug 7 09:57:36 2026] connection8:0: detected conn error (1019)
[Fri Aug 7 09:57:38 2026] connection8:0: detected conn error (1019)
[Fri Aug 7 09:57:39 2026] sd 15:0:0:1: [sdc] Synchronizing SCSI cache
[Fri Aug 7 09:57:39 2026] sd 15:0:0:1: [sdc] Synchronize Cache(10) failed: Result: hostbyte=DID_TRANSPORT_FAILFAST driverbyte=DRIVER_OK

Restarting a bunch of Docker containers, followed by restarting the VM instances fixed the problem (specifically I restarted iscsid, tgtd, cinder_volume and nova_compute on all my storage and compute nodes).

Of course this is a bad fix if I have to do it every week.

Now, Gemini is telling me this is a consequence of using Cinder with LVM which, according to it "LVM + iSCSI is notoriously brittle for production OpenStack" and I should move to Ceph.

Is this true, or should a Cinder/LVM setup be a bit more resilient?

Context/extra info: my deployment is a Kolla-Ansible one (2025.1) and Ceph is no longer deployed by this version. I would need to deploy it separately.

I have two storage servers (each with 50T, which I cannot physically transfer to the other) and I would like to make all this space available for volume creation.

I´m deplying through Kolla-Ansible and the sources are a bit contradictory on this. Some say that I can just put the following in globals.yml:

enable_cinder: "yes"
enable_cinder_backend_lvm: "yes"
cinder_volume_group: "cinder-volumes"

And list both nodes in the inventory under [Storage] (after creating a VG called "cinder-volumes" in each machine). The prechecks complain about a cinder_cluster_name, and setting it resolves the prechecks errors. But every documentation on "cinder_cluster_name" setting says that it won't work with LVM.

Anyone with experience putting cinder with more than one LVM cinder-volume? Will it create conflicts?

Hi all

One of the storage nodes on my OpenStack cloud has a fairly big raid 5 array, totaling 50T.

I'm new at managing such big capacities and a bit afraid of just creating a monstrous lvm volume that would make fsck and backup a nightmare.

So my question is, if I am to make a bunch of smaller volumes, what would be a decent compromise between cumbersome big and just too small?