Rsync, ZFS send and lz4 implications

[aufalien]

Hi,

I'm getting a rather nice 1.45 compression ratio on my data set using lz4.

I've 2 ZFS servers, replicas of one another pretty much except for data.

Now rsync will send the data uncompressed over the wire unless I specify -z. Will zfs send respect the compressed nature of the source data and send it compressed to its destination?

Mind you, source and destination are configured in the same way in terms of data sets, compression, etc...

Thanks in advance.

 

[cyberjock]

I think you're misunderstanding what -z does.

-z compresses the stream with rsync. So in your case, the data would be decompressed by zfs, compressed by rsync for transfer to the destination system, decompressed on the destination system, and then recompressed again by ZFS if you have compression enabled on the destination server.

If you aren't wanting to do all of that compressing/decompressing you should use ZFS' snapshot/replication feature. I'm pretty sure that the snapshot and replication will send the data in its compressed ZFS state as long as both sides support it.

 

[aufalien]

Hi,

This is EXACTLY the kind of info I need. And yes, I did understand the decompress-compress-decompress-compress path the data would take in the rsync and was hoping to avid that.

So many thanks Cyberjock. I'm stoked.