I have been running an ESXi 4.0 server for months with a couple of WinServer2003 and several Ubuntu Server 10.4 VMs. The performance has been impressive on 6GB i7 Asus P6T hardware. Suddenly, a week ago, the Ubuntu VMs take 8 minutes to log in over ssh when connecting over the LAN. The password prompt arrives immediately, and failed passwords are responded to immediately, but the moment I log in the prompt appears and I hang for many minutes.
This behavior is NEVER seen when I connect with vSphere Client. Using vSphere Client the Ubuntu VMs all respond beautifully.
I have seen: http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&externalId=1003496&sl...
Any other suggestions very welcome - thank you.
Hi,
you check setup of DNS (/etc/resolve.conf)
Ubuntu search reverse record of your management PC...
Or look here: http://blog.arunstephens.com/2008/11/21/ssh-slow-to-login-disable-reverse-dns-lookup/
It doesn't look like it is a reverse DNS lookup issue. Tested your suggestion of course and it doesn't fit with the fact that some of the VMs are responsive. So I'm still stumped.
whats the performance like when initiating a connection from a ubuntu VM? or from one ubuntu VM to another?
Good idea - just tested that.
From one Ubuntu VM into another the result is a 'hang' as described. To other Ubuntu VMs (same OS version 10.04) the performance is snappy and responsive.
I'm beginning to think that the problem might have little/nothing to do with ESXi.
is it any quicker if you connect via IP address rather then by hostname ?
Thanks 'vlho'.
I see I was not clear enough. I do not seem to be having a DNS problem as described since they seem to talk about the LOGIN prompt being delayed. I >do< get a password prompt - promptly. Often I get a prompt after I have logged in.
But the shell "hangs" for 10 minutes. After the 10 minutes the shell works. If I'm on the LAN the connection will stay up for the 10 minutes. Of course, if I'm coming in from outside the connection is terminated for inactivity after a few minutes (<10 minutes).
Do you agree?
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Here is the verbose ssh login information in case that helps:
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Message was edited by: rfreytag
@lw123 - thanks for your question.
No it is not any faster with the IP# because the problem happens after the password has been accepted. Sometimes it even gives me the shell prompt and accepts a command - then it hangs.