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Upgrade straight from Freenas9.10 to 12.0-U2

Western Digital Drives - The Preferred Drives of FreeNAS and TrueNAS CORE


Feb 15, 2021
I've got an old nas that's running 9.10 that I've not been motivated to touch for a long while... but I think it's time to upgrade to something actually supported and developed on, so 12.0-U2, I guess. The question is: can I just upgrade straight from 9.10 to 12.0-U2 without any interim stages or is that madness? I've read a few posts (e.g.) that detail things to be aware of between particular major releases but is jumping multiple major releases a thing?

I do have an encrypted raid-z pool of 3*8TB HDD that i'd rather not decrypt or have to restore from the backup because it'd take ages. The system dataset and the jails are on a seperate (unencrypted) 120GB SSD though, and I think the actual boot is off a USB key connected directly to the mainboard, (might even be two of them, I forget now and the inside of the box is a jumble).

Worst case, I'm willing to put up with recreating jails and setting stuff up again as long as the encrypted pool is going to be okay.


Ninja Turtle
May 26, 2011
Be aware that...
9.x used warden for jails (iocage does not exist there)
11.1 and 11.2 supports both warden and iocage - they can co-exist and you can start/stop both jail types (optimal to migrate)
11.3 and 12.x uses only iocage for jails and you can't start warden jails anymore. (There are migration scripts with various community-based improvements and fixes ... search this forum or r/freenas)

Also 9.x was running fine from USB as the system FS was read-only but 11.2 (or 11.3? i don't remember) changed that and the filesystems are now read-write. Cheap USB dongles tends to die in a no time (three died on me within a 6 months, then i migrated to SSD and no issues since then)
This changed in 9.3, thx @danb35 for correction

For the encrypted pool .. personally i would physically disconnect the disks and do the upgrade without them. Once you're done i would just import the pool back. Before you do so backup GELI metadata and GPT partitions (just in case **** hits the fan)

For GPT backup do following for each of your disks. Also make sure you use a proper disk serial so you know which file belongs to which disk
dd if=/dev/da0 of=/mnt/<some_path>/gptbackup/da0_<disk_serial>.mbr.backup bs=512 count=3

And for GELI metadata do the following for each disk. Make sure you use p2 in this case. Again use proper serial numbers for easy identification
geli backup /dev/da0p2 /mnt/<some_path>/gelibackup/da0p2_<disk_serial>.eli

Also the jump from 9.x to 12.x is pretty long. Lot of the things changed so expect to end up in a wrecked config in some areas. Make sure you have full documentation/screenshots of whatever you have configured at this point. For example netwok/vnet changed a lot so if you're using Jails with vnet/vlans this will get broken for sure and you will have to reconfigure it once you're on 12.x

Seems like you have backup but still i need to say it ... Ensure you have a fresh and working backup

Good luck :]
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Feb 15, 2021
thanks. I remembered reading something about jails changing but missed the details (and I'm glad there are migration scripts).

Re: the boot now being read/write and USB no longer recommended - it's a bit inconvient because the SSD I'd ideally use is the one that currently has the system dataset on it (and the jails)... but reconfiguring that means wiping and starting from scratch :/
I'm assuming it'll be possible to partition and still use it the system dataset and jails as well as boot? Or does it need to be a decidated drive (losing a sata port would the biggest negative about that!)

But good to know I'll need to do something about it sooner rather than later.


Nov 6, 2013
using a usb is still fine it's just some users had bad experience with them failing. Not everyone did though.

I would suggest doing a fresh install at this point if you feel like you can setup the system again. Doing an upgrade seems like alot of work.


Wizened Sage
Aug 16, 2011
Also 9.x was running fine from USB as the system FS was read-only but 11.2 (or 11.3? i don't remember) changed that
That change happened with 9.3. The 9.2.x releases and earlier loaded into a RAMdisk; 9.3 and later are a live ZFS pool.


Senior Member
Oct 23, 2020
Depending on your motherboard you might not be able to boot. My old NAS (AMD Phenom(tm) II X4 945 Processor) is on FreeNAS 11.1 and that was the highest version I could get to work.