Is it possible to disable SSH encryption during VM migration process?

[SuSt]

Hello, all.
Great respect to developers.

I have two servers running ProxMox VE. The both have an additional gigabit NIC (network interface controller) connected directly with its neighbour by a cross ethernet cable. The PVE cluster containing the boxes is built using this direct link.

So, I would like to have a very quick VM migration from one physical box to other. But I have found out, that despite the gigabit link, the data transfer speed is limited by CPU due to performing encryption/decryption operations implementing SSH protocol. But I don't need any encryption, because my systems are connected directly without any intermediary. I need hihg perfomance instead.

Is there any simple way to disable encryption and increase speed of VM migration?

Thank you.

 

[dietmar]

Is there any simple way to disable encryption and increase speed of VM migration?

no, currently not - we already use the fastest cipher (blowfish) available.

 

[SuSt]

Such a pity...
My gigabit LAN allows maximum transfer rate at 95 MBytes/sec. I have mesaured it using "dd" and "netcat". But with traffic encryption the speed decreases down to 30 MBytes/sec in spite of having 4-core Intel Xeon CPU E5430 @ 2.66GHz inside each server. Just because the process of in-flow encryption cannot be paralleled.

So, it would be a great improvement - to provide the possibility of VM migration without encryption.

 

[slumba]

You might find this thread useful:

http://serverfault.com/questions/116875/how-can-i-disable-encryption-on-openssh

Also, if you can figure out how to differentiate those times when the VM migration occurs, or feel comfortable modifying the scripts, you could create a separate ssh config file and use just that for this particular action (or by either the config options on the command line used). This would give you the advantage of making sure that your regular SSH sessions would not be affected.