SMB transfer creates huge load

[Marco Ertel]

Hi,
on my freenas/truenas the load goes up to 12 and more as soon as I transfer lot of data using SMB. I use this for sending my backup to the NAS. If then the load is so high I also see that at least one of my VMs (which is running my homeautomation server) also has a kind of reduced power. I regularly measure from there the network bandwidth of my internet connection. Even if there is network capacity on the network interface of the NAS these numbers are going down massively. Till yesterday I had the most recent 11 and then I switched to 12 beta 2.1. But this does not change this behavior.
Has somebody else seen something like that? Is it normal that the load with a single SMB transfer goes that high?

Here my spec:
motherboard: Fujtsu D3417-B
Processor: Intel Xeon E3-1225v5
RAM: 16GB ECC
HD: 6*14TB Toshiba Enterprise MG07ACA SATA
one pool with RAIDZ2
backup connection with SMB, used compression gzip(default, level 6)

Screenshot of htop where the high load is visible:

Here the screenshot from the reporting (there the start of the transfer can be seen):

Has somebody an idea if this should be normal or what I can do to improve the behavior?

Many thanks and kind Regards
Marco

 

[vangoose]

Turn compression off and try.

 

[c77dk]

What speeds do you see? I think that would be quite important

The one thing just popping up is the use of gzip(6) instead of lz4 - gzip can be very cpu hungry

 

[Marco Ertel]

average speed was around 500Mbit/s (machine is connected via GBit interface).
The CPU itself was not completely used (up to my understanding):

and here the network:

Does this really look like a gzip issue? Let me try it out with LZ4.

 

[c77dk]

gzip isn't using multiple cores and neither do SMB - so I would guess you're going to see an improvement. From your graphs the server is using about 50%, which in turn could be 2 cores on your cpu - one for gzip and one for SMB

 

[Marco Ertel]

ok it seems you're completely right. I changed to lz4 compression and it was much better. Average speed went up to 680MBit/s and here the screenshots of htop and the reporting:

ok. I had not expected such a huge difference.

Thanks for your help!

Marco