*New 12.1 series Release:
2020-04-17: XigmaNAS - released

*New 11.3 series Release:
2020-04-16: XigmaNAS - released!

We really need "Your" help on XigmaNAS https://translations.launchpad.net/xigmanas translations. Please help today!

Producing and hosting XigmaNAS costs money. Please consider donating for our project so that we can continue to offer you the best.
We need your support! eg: PAYPAL

SSH speed improvement

Secure shell connections.
Forum rules
Set-Up GuideFAQsForum Rules
Post Reply
experienced User
experienced User
Posts: 83
Joined: 14 Jul 2014 09:45
Status: Offline

SSH speed improvement


Post by erik »

On one of my systems I use a rather slow CPU and sending big files or replicating snapshots over SSH becomes CPU bound.
The solution I found is to set the cypher to

Code: Select all

as this will use the HW of the CPU in a more efficient way.
With this I easily reach 100MByte/second snapshot replication even on this slow CPU

Any other suggestions on how to improve speed / reduce CPU loading?
primary NAS: 2*8Tb raidz1, backup NAS: 6*2TB raidz2, remote backup NAS: 3*2TB raidz1 : All NAS4Free 11.0

experienced User
experienced User
Posts: 82
Joined: 09 Mar 2017 01:30
Status: Offline

Re: SSH speed improvement


Post by 744700595 »

I can't understand it. Is this code copied to the configuration inside the SSHD?
Favorite to kill the red devil
FreeBSD users from China. English is limited and posted using Google Translate. If the expression is not clear, please forgive me!

User avatar
Lee Sharp
Advanced User
Advanced User
Posts: 255
Joined: 13 May 2013 21:12
Status: Offline

Re: SSH speed improvement


Post by Lee Sharp »

Seeing as how I was a bit interested in this I dug a bit. I am hoping this saves other ther trouble. On the slow system under the ssh service in Additional Parameters, set "Ciphers aes128-gcm@openssh.com" and save. This means any system connection will use this cipher that is less computational intensive. By default, there are many options, and some are computational a bit harsh on older CPUs. Note this will also work for rsync! Running "ssh -Q cipher" will tell you the options you have enabled. It is interesting to do this when you have an older version... As for raw performance, 3des-cbc may actually be fastest, but it is not as secure.

Post Reply

Return to “SSH”