faster rsync (ssh cipher choice)

Perhaps the bottleneck isn’t always bandwidth – but does changing ssh cipher make any difference?

Using a derivative of :

rsync -W --delete --no-owner --no-group --no-perms \
    -e ssh \
    -arv /source/ remote@destination:/destination/path/

In unscientific tests, it looks like ssh parameters might do something when copying a 4GiB file between two random virtual machines in different data centres, but both in London.

SSH Variant	Speed
-e “ssh”	~45MB/s
-e “ssh -x -T”	~44MB/s
-e “ssh -x -T -c chacha20-poly1305@openssh.com”	~42MB/s
-e “ssh -x -T -c aes128-ctr”	~47MB/s
-e “ssh -x -T -c aes256-gcm@openssh.com”	~50MB/s
-e “ssh -x -T -c aes128-gcm@openssh.com “	~45MB/s

I’m not sure if these results are particularly insightful / useful.

Posted

November 30, 2022

linux, performance, sysadmin

David Goodwin

Tags:

rsync, ssh

Comments

2 responses to “faster rsync (ssh cipher choice)”

Duncan

November 30, 2022

You can rebuild ssh and sshd with a null cypher for benchmark purposes if you’re interested. Turning compression on and off can also make a big difference depending on the CPU availability on both ends. There are also multi-threaded versions of both client and server that can help.
David Goodwin

November 30, 2022

Thanks – I was sure I’d written something before about speed(s) but couldn’t immediately find it 🙂 this was a poor mans attempt at stopping myself from doing pointless premature optimisations in the future !

faster rsync (ssh cipher choice)

Comments

2 responses to “faster rsync (ssh cipher choice)”

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