Slow (300Mbps) ZFS Replication

[depasseg]

I'm just starting to use ZFS Replication from one server to a second on my local network. rsync would push the full 1G network, but I haven't seen anything close to that with ZFS replication. I've disabled both Stream Compression and the Encryption Cipher.

Does this seem normal? Is there anything I can try to improve performance? Is the CPU that limited?

Here's the PUSH system (full specs are in my sig):

Here's the PULL system (this is actually a Netgear ReadyNAS (upped to 8GB RAM) and an install of FN):

Here's some graphs from PULL:

 

[zambanini]

did you enable High Speed Cipheres?

your sshd cpu load should go down drastically.

 

[depasseg]

I did not. I used no cipher. I'll try it.

 

[zambanini]

status?

 

[depasseg]

High speed was slower than disabled. I'm just living with it.

I did a manual (CLI) ZFS replication as a test and it saturated the 1gb link, so I think there is an issue with SSH.

 

[cyberjock]

High speed was slower than disabled. I'm just living with it.

I did a manual (CLI) ZFS replication as a test and it saturated the 1gb link, so I think there is an issue with SSH.

Sounds exactly like a CPU bottleneck then if changing to high speed cipher makes it slower.

The CPU you are using on the Pull system is about 1/2 the processing power that we recommend as the minimum, so I'd kind of call it "expected behavior". It also has the minimum RAM (8GB).

 

[diedrichg]

I did a manual (CLI) ZFS replication as a test and it saturated the 1gb link, so I think there is an issue with SSH.

Sounds exactly like a CPU bottleneck then if changing to high speed cipher makes it slower.

If he did a CLI ZFS replication and it went full throttle, then would it really be CPU/RAM limited?

 

[cyberjock]

If he did a CLI ZFS replication and it went full throttle, then would it really be CPU/RAM limited?

Absolutely. If you are doing it via CLI there is no SSH tunnel unless you created the tunnel at the same time. ;)

I've never seen anyone every try to do an SSH tunnel with ZFS replication over CLI as there's really not much value added for troubleshooting purposes. ;)