On 09/30/11 05:14 AM, erik wrote:

On Thu, 29 Sep 2011 21:13:56 +1300, Ian Collins wrote:

   I have an application that iterates through snapshots sending them to
a remote host.  With a Solaris 10 receiver, empty snapshots are received
in under a second, but with a Solaris 11 Express receiver, empty
snapshots are received in 2 to three seconds.  This is becoming a real
nuisance where I have a large number of snapshots in a filesystem that's

For example:

receiving incremental stream of export/vbox@20110927_1805 into
received 312B stream in 3 seconds (104B/sec)
receiving incremental stream of export/vbox@20110927_2205 into
received 312B stream in 2 seconds (156B/sec)

The change looks to be increased latency, bigger snapshots still appear
to be received at the same speed as before.

Does anyone know what has changed to cause this slowdown?

I think that's pretty much the baseline overhead required for validating the consistency of the snapshot and it's applicability on the destination pool. I have similar numbers on a little NAS dumping to a set of external USB disks that behave in a similar manner:

That does appear to be the case, but I was wondering why it has become so much worse?

I am in the process of copying some large data sets to a new server and the whole process it taking way longer than I expected (there are thousands of small snapshots).

Slowing down replication is not a good move!


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