<![CDATA[Backing up to NFS share on ZFS]]>I'm testing XO. I have an NFS server with ZFS (compression + deduplication enabled).

Would backing up to this nfs share cause problems for backups & restores?

]]>https://xcp-ng.org/forum/topic/5068/backing-up-to-nfs-share-on-zfsRSS for NodeSat, 09 May 2026 14:22:50 GMTFri, 15 Oct 2021 18:34:10 GMT60<![CDATA[Reply to Backing up to NFS share on ZFS on Wed, 10 Nov 2021 01:23:07 GMT]]>@indyj The file restore issue was due to installing XO on FreeBSD (fine for VM restores, not file extraction).

I then installed XO on Ubuntu 20, and this worked for restoring files from Linux VMs but not Windows VMs.
Then I installed on CentOS 8 and had the same problem as Ubuntu.

I then installed on Fedora 34 and everthing works fine.

]]>https://xcp-ng.org/forum/post/43774https://xcp-ng.org/forum/post/43774Wed, 10 Nov 2021 01:23:07 GMT<![CDATA[Reply to Backing up to NFS share on ZFS on Thu, 28 Oct 2021 14:44:00 GMT]]>@indyj So I went to the logs and pasted the command directly into the shell. while the vhd file does exist the mount point does not.

The command assumes a temporary directory within /tmp that is not getting created by the script.

If I create the directory and paste the command into the shell the vhd does mount.

]]>https://xcp-ng.org/forum/post/43485https://xcp-ng.org/forum/post/43485Thu, 28 Oct 2021 14:44:00 GMT<![CDATA[Reply to Backing up to NFS share on ZFS on Wed, 27 Oct 2021 20:59:37 GMT]]>Thanks for the tips.
When I try to restore an individual file from the server using ZFS compression & dedupe XOA gives me an error: "Error while scanning disk"

I'm wondering if the compression or dedupe is the likely cause. My money is on the Deduplication. Any thoughts on this?

]]>https://xcp-ng.org/forum/post/43456https://xcp-ng.org/forum/post/43456Wed, 27 Oct 2021 20:59:37 GMT<![CDATA[Reply to Backing up to NFS share on ZFS on Wed, 27 Oct 2021 05:26:29 GMT]]>@indyj Probably when you use rsync, the files are transferred with larger blocks with few fsyncs. Perhaps when XO does it it is 4k transfers with fsync between each, which limits compressability a lot. Just a thought.

]]>https://xcp-ng.org/forum/post/43416https://xcp-ng.org/forum/post/43416Wed, 27 Oct 2021 05:26:29 GMT<![CDATA[Reply to Backing up to NFS share on ZFS on Tue, 26 Oct 2021 22:31:31 GMT]]>@indyj

What does zpool list show from the cli? Looking for dedup-rate on the dataset that holds the backups.

]]>https://xcp-ng.org/forum/post/43413https://xcp-ng.org/forum/post/43413Tue, 26 Oct 2021 22:31:31 GMT<![CDATA[Reply to Backing up to NFS share on ZFS on Tue, 26 Oct 2021 11:55:26 GMT]]>Not being a ZFS expert here is an oddity: I have two old servers I use for backups. One is NFS with XFS filesystem (testing XO backups). The second is NFS with ZFS.

I copied my data from the server with XFS to the one using ZFS via rsync: A 17 Terabyte NFS/XFS share used only approximately 7 Terabytes on the ZFS server.

However If I backup data via XO to the NFS share on the ZFS system I don't seem to save space compared to backing up to NFS on the XFS filesystem.

I'm using lz4 compression & Dedupe on the ZFS system..

]]>https://xcp-ng.org/forum/post/43400https://xcp-ng.org/forum/post/43400Tue, 26 Oct 2021 11:55:26 GMT<![CDATA[Reply to Backing up to NFS share on ZFS on Fri, 15 Oct 2021 19:16:10 GMT]]>Yeah dedup could cost a lot. Maybe it's better to enable it for a backup storage for XO backups, not for your VMs.

]]>https://xcp-ng.org/forum/post/42986https://xcp-ng.org/forum/post/42986Fri, 15 Oct 2021 19:16:10 GMT<![CDATA[Reply to Backing up to NFS share on ZFS on Fri, 15 Oct 2021 19:15:23 GMT]]>@indyj have the same nfs on zfs setup here (minus deduplication) running on a truenas box.
xcp-ng using the nfs share for backups is working fine for me

]]>https://xcp-ng.org/forum/post/42985https://xcp-ng.org/forum/post/42985Fri, 15 Oct 2021 19:15:23 GMT