Lvm – Failed to find logical volume “group/swap”

LVM does backup it's metadata to /etc/lvm/backup and /etc/lvm/archive. At the top of each file it will tell you the time/data when the file was generated so chances are you'll have a copy of the older metadata as it was before you deleted the LV. I believe the backup is automatic anytime the metadata changes.

The following can be dangerous and destructive so be very careful and if possible have a full backup.

The command to restore these volumegroup metadata backups is vgcfgrestore. Make sure you make a current copy of the existing working configuration using the vgcfgbackup command with the -f flag to specify a different file for the output so that you don't alter any files that are in the /etc/lvm/backup or /etc/lvm/archive folders. Make sure you diff the current configuration with the configuration you wish to restore to verify that the only changes you're about to apply are to recreate the recently deleted LV. Having a full backup of your data probably isn't a bad idea either. You may also want to consider contacting your Linux vendor for support/guidance if you're under a support contract before proceeding as I've never had to do this myself.

Good luck.

I don't dare answer this because it sounds like it is clvm specific and I don't know clvm. But I wouldn't assume that something that works with the clvm layer, even with a single node, works the same without. (edit: I see this vg is outside the cluster)

Now for some nonspecific advice: keep everything readonly (naturally), and if you recently made any change to the volumes, you'll find a backup of previous layouts in /etc/lvm/{backup,archive}. Those are applied with vgcfgrestore --file /path/to/backup vg. One is your current configuration, and the rest are only useful if the lvm metadata was lost, erased, or got out of sync. Before trying to roll back check if the dates make sense, and diff with your current configuration (do a vgcfgbackup to some external location).