Hacker News Reader

Comment by jimmcslim | Hacker News Reader

I have an Ubuntu server with a ZFS pool that I want to rebuild as a FreeNAS/TrueNAS server. Can I use something like rsync.net to push my datasets up as a backup, rebuild my server, and then pull them back down into a reorganised/renamed tree of datasets? Are there compatibility issues between ZFS on Linux and ZFS on FreeNAS that I need to be concerned about? (that come into play when pushing/pulling datasets)

View on HN

> Can I use something like rsync.net to > push my datasets up as a backup

Yes, but depending on the size/value of the dataset, rsync might not be the best option.

Even after recent price reduction (Yay!), and with a hn discount (Yay!) - I still consider rsync.net as a personal backup service a little overkill/expensive past 100 GB or so. And likely you could just handle anything on the order of 1 to 2 tb locally anyway (spare disks).

You technically could use it for 10+tb of data... But uploading and downloading is going to be slow unless you have a real uplink (ie at least 1gbps).

And if you did, unless you need filesystem level Metadata - rsync might be a better option than zfs send/receive (even though zfs is cool).

>, rebuild my server, and then pull them back down into a reorganised/renamed tree of datasets?

Again, if you just need the data back - you might be well served with rsync or restic (both choices should be orthogonal to using rsync).

> Are there compatibility issues between ZFS on Linux and ZFS on FreeNAS that I need to be concerned about?

The world is divided in Oracle and not-Oracle - AFAIK there shouldn't be major differences between those two - that I believe now both follow upstream zfsonlinux.

However - I believe rsync.net still doesn't support zfsonlinux/openzfs encryption (zfsonlinux 0.8+). While locally it's possible to encrypt the disk "under" zfs... Native encryption is tempting.

And you would of course never send anyone data without encrypting it?

The switch of FreeBSD's ZFS master being ZoL is still work in progress, and is not the default ZFS in FreeBSD yet. (FreeNAS being FreeBSD + Configuration + Management Software).

A fair number of the ZoL 0.8 features (encryption, allocation classes being two prominent examples) are not available currently for FreeBSD

Allocation classes are available in FreeBSD CURRENT snapshots.

I just did this last weekend, except I have 2 local servers that can hold all my data in a pinch.

I tried to directly import the Linux created pools into freenas, but they are read only due to a feature property that’s only supported by ZoL.

In read only mode I sent everything to the backup Linux server, destroyed the main pool and sent the whole thing back to the Freenas setup.

Your pools may have incompatible features in use that would prevent this. I recently set up an Ubuntu (19.10 desktop) box and cannot recv it's datasets on FreeNAS.

For now I'm just doing rsync of the snapshot directories, not upgrading the Ubuntu pool, and waiting on FreeNAS feature support to match.

Just out of curiosity why do you want to rebuild this as a FreeNAS server?

I should also mention that this is actually an Ubuntu VM running in Hyper-V on a Windows Server 2012 host... don’t ask! It needs to be rebuilt one way or another (and it is running on an HP Microserver N54L!)

As for FreeNAS, I feel it gives the closest thing to a Synology NAS in terms of manageability through a GUI, etc, while also supporting ZFS.

Ahh, I don't have the hardware to run zfs in a VM, for home I run a big zfs array on bare metal and also host some vms next to it. If I were running zfs in a VM itself I would be more open to freenas.

Maintaining freenas and trying to run some other virtualized apps next to it was not good for me.

Reply on news.ycombinator.com