pve-zsync and "ZFS over iscsi" storage


Well-Known Member
Jul 6, 2016
Hi @ all,

when trying to backup a VMs disk with pve-zsync that is located at a "ZFS over iscsi" storage, I am getting "ERROR: in path".

Is it possible that this does not work with "ZFS over iscsi" storages?


ZFS over iSCSI is on your local machine an iSCSI and not a ZFS.
So you can't sync on your localhost.
You must install it on the NAS but there is no VM config.
What you can try is to use as --target the remote IP with the zvol path of the iSCSI.
Sorry I meant --source
So which would be correct?

pve-zsync sync --source iscsimachine:100 --dest iscsimachine:/rpool/backup

Or this:
pve-zsync sync --source iscsimachine:/rpool/data/vm-100-disk-0 --dest iscsimachine:/rpool/backup
As I wrote before the config is on your local machine.
For the NAS it is just a zvol so you have only the path to identify.

But I think the path of the second command is not correct.
And anyway why do you what to make a backup from the
iscsimachine to the iscsimachine?
Also, iscsimachine must be a resolvalbe hostname, better use IP address instead.
The NAS is a proxmox node that has targetcli running.

Some of our KVMs that are running on ssd nodes has additional ISCSI disks to the "iscsimachine" which has hdds for "slow big storage".
Now when I do a pve-zsync of the KVM, I am getting the error mentioned above.

Because on the scsimachine I have different pools with different disks, it would not be bad to have backups like form "iscsimachine/iscsipool" to "iscsimachine/backuppool".

The stuff with IP, etc. is clear. I am running a bind dns for local name resolution.
But then it would be better to run it on the iscsimachine locally and not remote.
pve-zsync sync --source rpool/data/vm-100-disk-0 --dest /backup
Hmm... wouldn't I have the same problem that no vm.conf file is available on the iscsimachine?
And this way I would have to run pve-zsync two times. One time on the node (where I would have to configure the iscsi disk vm-100-disk-0 as "nobackup") so that I do not get the error message, and the second time directly on the iscsimachine as you mentioned, right?
Hmm... wouldn't I have the same problem that no vm.conf file is available on the iscsimachine?
The config you get in no case because it is a local resource.
I would run the pve-zsync on the iscsimaschine and backup the config with vzdump and do not include the disks in the backup.
This way only the config will be backuped.
Well but in my example this would be bad because the KVM could have additional local-zfs disks. This is why I wanted to let it run on the node and on the iscsimachine
This use case is not covered.
Hi, did not really got you last info...
What means "not covered"? If I configure in the vm.conf for the iscsi drive "nobackup" I can run the pve-zsync backup for the local disk without a problem. Additionaly, I would use the pve-zsync on the iscsimachine to do the backup like you mentioned.

Another idea was to just use "zrep" to replicate directly on the iscsimachine from one pool to the other.


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