Re: zfs replication tool

On Fri, 16 Sep 2022, at 13:30, Julien Cigar wrote:
> Hello,
>
> I have the case here where I have to atomically snapshot recursively a 
> dataset with many children (100+) but exclude a dozen of them.
>
> There are dozen of ZFS replication tools and I was wondering which ones
> supports such case and are recommended?
>
> It looks like "recursivity" in a lot of tools is handled through "zfs
> snapshot -r somepool" whereas ZFS also supports "zfs snapshot
> somepool/ds1 somepool/ds2 somepool/ds3/child1" which is also atomic
>
> Thanks!
>
> Julien

Look at zfs-program(8) to get your atomic snapshot requirements, while
still excluding some of them. https://man.freebsd.org/zfs-program

"The ZFS channel program interface allows ZFS administrative operations
to be run programmatically via a Lua script. The entire script is executed
atomically, with no other administrative operations taking effect
concurrently. A library of ZFS calls is made available to channel program
scripts. Channel programs may only be run with root privileges."

https://klarasystems.com/articles/understanding-zfs-channel-programs/

This doesn't help you with your zfs send constraints though, you'll
still need to traverse these manually for sending.

I'd be interested to know if you can `zfs send pool/foo@bar` when not
all datasets under pool/foo have a snapshot @bar...

Do let the list know what ended up working out. Blog posts on complex
zfs setups are always welcome.

A+
Dave