Migrating from FreeBSD

[jlauser]

Hi all.

I have a FreeBSD machine at home that I've been running since... basically 2003. It's gone through numerous hardware and software upgrades since then, but while I was interested in tinkering with the machine back then, today I really just want the thing to sit and do its job and not have to worry about it. As such, I'd like to migrate the machine from FreeBSD where I have to do all of the software management myself to FreeNAS where everything is more... turn-key. The machine is currently running FreeBSD 12.1.

Right now the machine essentially serves two functions:

• File server (AFP and NFS)
• VM host (a few Linux machines, managed by bhyve)

All of the storage on the machine is ZFS, split into two pools:

• root pool
  • 2x SATA SSDs connected to the motherboard's SATA controller
    • mirrored vdevs
• storage pool
  • 4x SATA HDDs connected to an LSI SAS-9217 HBA (the HP OEM branded version of the SAS-9207)
    • 2x2 mirrored vdevs
  • 2x NVMe SSDs in M.2-to-PCI adapters (the system BIOS does not support booting from NVMe devices)
    • each split into two partitions
      • mirrored logs
      • striped L2ARC

What I would like to do is install FreeNAS onto the drives that are currently the root pool and then import storage pool. Obviously I don't expect that FreeNAS will magically import all of my file share settings and VM configuration, but what I need to know is if:

1. FreeNAS will be able to read the storage pool without risk of data loss, and
2. Once I recreate the VMs in FreeNAS, will I be able to point them to the zvols that currently represent their virtual disks, will they work as if nothing changed?

I do have a backup of my data, but it's offsite and retrieving it would be... very time consuming (the backup machine is already running FreeNAS). I do not have sufficient hardware sitting around my house to build a new FreeNAS machine from scratch and replicate the data over.

Thanks in advance.

 

[seanm]

One thing I wonder: FreeNAS is currently on FreeBSD 11.3, do your ZFS storage pools use flags that 11.3 doesn't recognize?

 

[jlauser]

Comparing the flags on my FreeBSD 12.1 machine versus the FreeNAS 11.3 machine... feature@large_dnode is listed on FreeBSD but not on FreeNAS. It is enabled but not active on the FreeBSD machine. The man page for zpool-features says the following about enabled:

Code:

     enabled   An administrator    has marked this    feature    as enabled on the
           pool, but the feature's on-disk format changes have not been
           made yet.  The pool can still be    imported by software that does
           not support this    feature, but changes may be made to the
           on-disk format at any time which    will move the feature to the
           active state.  Some features may    support    returning to the
           enabled state after becoming active.  See feature-specific doc-
           umentation for details.

This leads me to believe that it should be compatible.