Guides for ZFS Full backup to NFS drive and restore from NFS drive

[Alejandro Imass]

On Sat, Oct 5, 2019 at 4:44 AM Polytropon <freebsd at edvax.de> wrote:

> On Fri, 4 Oct 2019 18:38:49 -0400, Kurt Hackenberg wrote:
> > On 2019-10-04 17:20, Alejandro Imass wrote:
> >
> > > Hi there FreeBSD folk!
> > >
> > > Are there any easy to follow guides to completely backup a FreeBSD
> system
> > > to an NFS drive and then restore the complete system from the backup
> in the
> > > NFS drive?
> > >
> > > I don't have much NFS expertise but it shouldn't be that complicated.
> > >
> > > I found this guide but not exactly what I'm looking for:
> > >
> > >
> https://www.dan.me.uk/blog/2012/08/05/full-system-backups-for-freebsd-systems-using-zfs/
> > >
>
>
[...]


> Definitely. It is possible (and probably the way to go in this
> scenario) to write the "zfs send" result to a file that is accessible
> via NFS, first for backup, then have a rescue system handy (for
> example, a FreeBSD live system CD, DVD, or USB stick) to boot
> the system from again, make any neccessary preparations, and
> then run "zfs receive" with the previously mentioned file via NFS
> as source. So basically it's what you do with traditional dump
> and restore via _files_ stored somewhere else on the network,
> but with ZFS tools. :-)
>
> Or did I misunderstand the question?
>
>
>
Nope you definitely understood the question precisely.

I have read enough to understand that the process is somewhat the following:

1) zfs snapshot
2) zfs sedn to a file
3) copy the file to the nfs mount
4) reconstruct my zfs raid (the main reason I am doing this)
5) zfs receive

But the devil is in the details and I have not found a single fool proof
recipe. IMHO the handbook still lacks a lot of practical information about
ZFS administration "for dummies".

The last time I blindly followed the handbook's limited recipes I did
"detach" and the "add" like the handbook suggests, and the reason I am in
this predicament in the first place:

https://lists.freebsd.org/pipermail/freebsd-questions/2018-November/283219.html

Kevin P. Neal knew the answer but came a little bit late after I had
inadvertently converted my pool into a stripe :-(

I probably wasn't the only one unable to find the right answer to a simple
problem in the current documentation:

https://forums.freebsd.org/threads/re-attaching-failed-device-to-pool.66027/

IIRC I did offer to collaborate and update the handbook for this particular
case (re-attaching a drive with the same uuid) but nobody provided any
pointers on who/how the handbook gets updated.

What I want to do now is backup the entire system, reconstruct the raid1
pool and then restore the whole system INTACT.

If there is no such documented recipe I am willing to fully document it
with you guys' expert's help here and then find a way to collaborate with
the handbook and add both use cases to it.

For the common user like myself I really feel the ZFS section in the
handbook needs a lot of work for practical day to day tasks, and the FBSD
ZFS Wiki, at least IMHO, doesn't offer much help either.

TIA!
Alex