execution of command before or when snapshot or replication starts

[LastManStanding]

I have set up a main server and a backup server. The main server take snapshots once a day and starts replication towards the backup server, so far no problem.

The backup server should not run all the time, but only if necessary. I.e., when replication starts or shortly before.

Wake on LAN works fine with wake command, but how to trigger wake command?

My current temporary solution starts waking up backup server by cron job shortly before replication starts. This means that main server must be running at exactly that point in time.

But as I'm currently analyzing when FreeNAS is used mostly and when not, I will also keep the option to shut down server if not needed. This means snapshot taking and replication should not be dependent to a small time slot during the day, it should be done when FreeNas means it can be done... just once a day and totally automated.

Question: Is there a possibility to bind command execution to the snapshot or replication tasks?

Thanks for Your Help!

 

[LastManStanding]

no idea? there must be some information somewhere in the system that leads to execution of snapshot and replication jobs... maybe it's possible to insert some extra code line?

 

[jgreco]

You're free to specify your own snapshot and replication script...

 

[LastManStanding]

you mean cron-job controlled execution of snapshot taking via script?

 

[jgreco]

Sure. The built-in system isn't really intended for lots of hooks.

 

[LastManStanding]

o.k., but cron-job execution again is bound to a time plan... what commands are needed to start snapshot taking by script? do you have command references?

Thanks!