Wait until the SAN and LUNs are available before continuing with the Proxmox boot process

[Nvaes]

Hello,

I’m using an LVM over iSCSI setup, but when there’s a power cut, the Proxmox hosts boot up before the SAN, which causes errors on the VMs.
How can I tell Proxmox to wait for the iSCSI LUNs before continuing the boot process?
Thank you

 

[guruevi]

There are a few ways to solve it:
The cleanest but most difficult way is whatever process is doing the re-connect (in this case iscsi.service likely) and make the dependent process wait on it. You can do a systemd override configuration on pve-guests.service for example.

Here is what this would look like:
systemctl edit pve-guests.service

[Unit]
Requires=iscsi.service
After=iscsi.service

You may need to play with it, not sure if iscsi creates specific units for disks that you can wait on for a specific target.

The easiest way is just to add some wait time to the boot. For EFI boot:
nano /etc/kernel/cmdline
Append rootdelay=15 to the end of the existing single-line entries (or whatever seconds you need to wait)
Run proxmox-boot-tool refresh to apply the kernel update

 

[bbgeek17]

Another approach is to write a healthcheck/probe script that all the other PVE services will depend on. Once the probe determines that SAN is up - it lets the others to proceed.
Or, the probe is independent and simply reboots the host when the transition happens from SAN offline to SAN online.

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