SOLVED How ZFS replication works on FreeNAS

[Oko]

I am trying to understand how ZFS replication works on FreeNAS 9.2.1.9 (possibly it is the same as 9.3). My conclusion from reading the user manual is that FreeNAS uses vanilla zfs send command possibly with few switches and schedules it as a cron job. Apparently it does that in semi-incremental backup. I am the most curios how taking snapshot triggers replication and how old replications gets deleted. However login into the shell and lunching crontab -e reveals that root crontab. Where should I look for the info (crontab file)? on the live installation. Can anybody help me located relevant code in the source

https://github.com/freenas/freenas

 

[Fei]

crontab file path : /etc/crontab

 

[Ericloewe]

FreeNAS 9.2.1.9 (possibly it is the same as 9.3)

Why are we talking about ancient and old versions, respectively?

I am the most curios how taking snapshot triggers replication

It doesn't. The replication script is invoked regularly and new snapshots get replicated.

 

[Oko]

crontab file path : /etc/crontab

You are right. system crontab should have being first place to look plus
/conf/base/etc/crontab Looking at the /etc/crontab reveals that FreeNAS 9.2.1.9 uses a custom Python script for snapshots /usr/local/www/freenasUI/toos/autosnap.py. That script calls another script /usr/local/www/freenasUI/toos/autorepl.py which does the replication. I am going through both right now. Thank you so much for your answer.

 

[Oko]

Why are we talking about ancient and old versions, respectively?

Because that is what I run in production since I am not eager to "upgrade" the file server holding home directories of 80+ people and create the crisis situation in my organization. I am in the process of migration to newer version but it will be vanilla FreeBSD 11.00 as I find I just need a minimum subset of FreeNAS functionality and no GUI.

No reason for the aggression.

It doesn't. The replication script is invoked regularly and new snapshots get replicated.

Yes I figured out that by looking at the /etc/crontab and going through respective Python scripts. Thanks for confirming that for me.

 

[Ericloewe]

No reason for the aggression.

No aggression is meant, it's a terse statement rolled together with a question, written from my phone.

 

[Fei]

You are right. system crontab should have being first place to look plus
/conf/base/etc/crontab Looking at the /etc/crontab reveals that FreeNAS 9.2.1.9 uses a custom Python script for snapshots /usr/local/www/freenasUI/toos/autosnap.py. That script calls another script /usr/local/www/freenasUI/toos/autorepl.py which does the replication. I am going through both right now. Thank you so much for your answer.

You want to use ZFS replication migrate your data from FreeNAS to other ZFS system ?
If so ,you can use zfs send/recv command .

 

[Oko]

You want to use ZFS replication migrate your data from FreeNAS to other ZFS system ?
If so ,you can use zfs send/recv command .

I was planning to export and import the pool but you are suggesting safer option.