SyncThing - TrueNas

[Porch01]

I am looking to have multiple jails for SyncThing. When I try to setup multiple jails, SyncThing doesn't start after creating a second jail. Is it possible to have 2 instances of Synching running on the same TrueNas system? If it is possible, what are the pros and cons of running 2 instances? Thank you.

 

[Patrick M. Hausen]

How are you creating your jails? Are you using the plugin? You cannot have more than once instance of any plugin, if I am not mistaken.
You can of course create an arbitrary number of standard jails and manually install any application in them.

 

[Porch01]

I think I meant mount points rather than jails. I am looking to setup multiple mount points within one jail of SyncThing but that doesn't seem to work.

 

[Patrick M. Hausen]

You can do that ... what precisely is the problem you are facing?

 

[Porch01]

First, I stop SyncThing. Then I go to Mount Points. Click Actions, then Add. I select a Source and Destination. I now have 2 mount points setup in SyncThing_Jail. I go back to the SynThing Plugin and try to restart it. It does not restart.

 

[Patrick M. Hausen]

Please show the configuration of the two mountpoints.

 

[Porch01]

Here is a screenshot of both mount points. If I remove the bottom one, SyncThing will start up. TrueNas version TrueNAS-12.0-U3. SyncThing version 1.15.1. Thank you for all your help so far.

 

[Patrick M. Hausen]

They cannot be nested. Plain and simple. You need two separate paths inside the jail.

E.g.

Code:

.../root/mnt/SyncThing/Data
.../root/mnt/SyncThing/Temp

 

[Porch01]

That was it. Thanks for your help.

 

[chx_b]

Perhaps I'm wrong about this, but I am under the impression that using Syncthing with ZFS is a pretty awful idea. Maybe someone can point to a better solution with an rsync setup to ameliorate this?
The reason appears to be that syncthing was not created to work with block-based filesystems like ZFS. (See comment section here)
It seems like (if I am understanding correctly) you end up with a ton of copies of the data everywhere - each time a very minor adjustment to the data occurs. Furthermore, ZFS tries to track all of these near-identical blocks - so the system ends up with a *ton* of space taken up by file copies (snapshots get far, far less efficient essentially).
The issue raised to syncthing shows they're not too interested in solving this behavior.

Again, I may be misunderstanding this, but the sentiment points towards **don't use syncthing on ZFS**.

Anyone know of a better solution?

 

[jgreco]

This would seem to be a problem if you want to snapshot the dataset or pool, yes, but if frequent and long term snapshots are not a requirement, then this is really only an exercise in CoW issues such as fragmentation. If you were only keeping, let's say, half a dozen snapshots and were not making deltas that involved terabytes of writes, this could be fine. But yes, it's a pain point.

I tend to architect my workloads to favor rsync (unidirectional). For bidirectional sync, I find Unison is still the best tool, even though it has limitations.