ZFS Replication - replicated side bigger?

[Sir.Robin]

So one of my datasets on NAS01 is about 180GB in size, with 5 snapshots.

I have replicated it to my NAS02 for over a year.

Then i moved it on the NAS02 side. from volume/dataset to volume/backup/dataset

Then i edited my replication task on NAS01 so my replication path is correct.

Replication ran tonight and completed successfully.

Now, all seems fine, except my replicated dataset on NAS02 is 205GB in used space instead of 180GB.

NAS01:

Code:

NAME                              USED  AVAIL  REFER  MOUNTPOINT
vol01/ftp@auto-20140224.0300-1m      0      -  157G  -
vol01/ftp@auto-20140224.1038-2m      0      -  157G  -
vol01/ftp@auto-20140303.1038-2m  336K      -  157G  -
vol01/ftp@auto-20140310.1038-2m  496K      -  157G  -
vol01/ftp@auto-20140317.1038-2m  480K      -  157G  -
vol01/ftp@auto-20140323.2010-2m      0      -  174G  -

NAS02:

Code:

NAME                                      USED  AVAIL  REFER  MOUNTPOINT
repl01/backup/ftp@auto-20140224.0300-1m  16.0K      -  181G  -
repl01/backup/ftp@auto-20140224.1038-2m  16.0K      -  181G  -
repl01/backup/ftp@auto-20140303.1038-2m  336K      -  181G  -
repl01/backup/ftp@auto-20140310.1038-2m  496K      -  181G  -
repl01/backup/ftp@auto-20140317.1038-2m  464K      -  181G  -
repl01/backup/ftp@auto-20140323.2010-2m      0      -  197G  -

Why is this?

 

[Sir.Robin]

Noone know or dare?

Here's my own take: Compression ffs. :D

 

[ser_rhaegar]

No idea why, but I can add my experience:
Compression on both sides.
Replicated data in some datasets is smaller.

My understanding is if it is compressed, it stays compressed when replicated. Which makes me wonder how my data gets smaller in some instances.

 

[Sir.Robin]

I had compression initially on sender side, not on receiving.

 

[Brian Tima]

I am seeing this on my replicated snapshots. Both ends are exactly the same. Is this a bug?

Production System:

Code:

NAME USED AVAIL REFER MOUNTPOINT
tank/dc1PoolDisk1@auto-20140617.1319-2w 53.1M - 381G -
tank/dc1PoolDisk1@auto-20140617.1519-2w 10.4M - 381G -
tank/dc1PoolDisk1@auto-20140617.1719-2w 3.06M - 381G -
tank/dc1PoolDisk1@auto-20140618.0701-2w 13.2M - 381G -

Replicated System:

Code:

NAME USED AVAIL REFER MOUNTPOINT
tank/dc1PoolDisk1@auto-20140617.1319-2w 115M - 831G -
tank/dc1PoolDisk1@auto-20140617.1519-2w 22.2M - 831G -
tank/dc1PoolDisk1@auto-20140617.1719-2w 6.54M - 831G -
tank/dc1PoolDisk1@auto-20140618.0701-2w 0 - 831G -

 

[dlavigne]

Did you figure this out?