Snapshot replication

[Jano]

Hi,

Can I kindly ask you to explain how freenas if working during snapshots replication when option "Delete stale snapshots on remote system" is turned on and how when it is turned off ?

 

[Robert Trevellyan]

Assume you have daily snapshots configured on the source, and those daily snapshots are configured to expire after a month. With deletion of stale snapshots enabled, any snapshot that has expired on the source due to being older than a month will be removed from the destination during replication.

 

[Jano]

Great, so I can tak conclusion that if I turn it off snapshots on "source" side will be periodically removed (base on defined time) and snapshots on "remote" side will NOT be removed, just collected.

Right ?

 

[Robert Trevellyan]

if I turn it off snapshots on "source" side will be periodically removed (base on defined time) and snapshots on "remote" side will NOT be removed, just collected.

Yes, that's my understanding. Honestly, I haven't tested it to be 100% sure.

 

[Jano]

Mine was also.

Problem I have is it is not working like this.

I have 13 replication tasks from one system (source) to another (backup).
On source system I have snapshots configured every 4h and keep it for 4 days.
They are transfered correctly on remote side but... on remote side I have only exactly last 4 days of backups.

Looks like source freenas remove also older snapshots on remote side.

Of course "Delete stale snapshots on remote system" is turned off for all 13 replication tasks.


Where is mistake ? Did I understand something incorrectly ?

 

[Robert Trevellyan]

The documentation of that checkbox says, "if checked, will delete any previous snapshots on PULL which are no longer stored on PUSH". To me, this strongly implies that the converse is true, i.e. unchecking that box should leave the older snapshots unmolested on the destination.

Might be worth filing a bug report.

 

[Jano]

Thanks for answer

 

[depasseg]

Of course "Delete stale snapshots on remote system" is turned off for all 13 replication tasks.

Sidebar: I've got to know why you have 13 different replication tasks?

 

[Jano]

Why 13 not one of parent storage with recursive option right ?

Well there is historical reason when some LUNs were "backuped" on different systems (some of them to backup1, some of them to backup2...).

In this moment 6 of them are replicated to system1/backup1 and 7 rest to system1/backup2

There is no known issue about not using such configuration.... af far as I know.

 

[depasseg]

Why 13 not one of parent storage with recursive option right ?

exactly, or only 2 with recursion if going to different systems.

No issues that I know of, except mgmt headache.

 

[Jano]

Well, I did it long time ago and forgot... as long as it is working I have other issues make me really headache :D

Anyway thanks for suggestion.

 

[Jano]

Bug declared: https://bugs.freenas.org/issues/12692