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SSH to VE is very slow [message #24994]

Wed, 12 December 2007 19:45

parf
Messages: 11
Registered: December 2007
Location: USA

Junior Member

SSH to VE takes 11 seconds to complete
# date; ssh hdb date
Wed Dec 12 14:35:16 EST 2007
Wed Dec 12 14:35:27 EST 2007

computer have 0 load.
# uptime
14:35:36 up 16 min, 3 users, load average: 0.00, 0.00, 0.00

Timeout occurs in

ssh -v ....
debug1: Trying private key: /root/.ssh/id_dsa
debug1: read PEM private key done: type DSA
--- 12 sec timout
debug1: Authentication succeeded (publickey).
debug1: channel 0: new [client-session]
debug1: Entering interactive session.

PS:
# ping hdb
PING hdb (10.1.148.120) 56(84) bytes of data.
64 bytes from hdb.xxx (10.1.148.120): icmp_seq=1 ttl=64 time=0.050 ms

# traceroute hdb
traceroute to hdb (10.1.148.120), 30 hops max, 40 byte packets
1 hdb.xxx (10.1.148.120) 0.057 ms 0.013 ms 0.011 ms

PPS:
vzctl enter works instantly

PPPS: no any messages in log files

Host is Centos5 VE is Centos5

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Re: SSH to VE is very slow [message #24995 is a reply to message #24994]

Wed, 12 December 2007 19:58

ugob
Messages: 271
Registered: March 2007

Senior Member

This looks like a PTR DNS search that is timing out.

Every time you do an SSH connection, sshd tries to find the PTR (also known as reverse DNS record) for this IP. If it can't find it, or can't find a server that knows it, it can cause such a delay.

Ugo

Please read the manual before asking questions:
http://download.openvz.org/doc/OpenVZ-Users-Guide.pdf

Please have a look at the wiki before asking questions:
http://wiki.openvz.org/Main_Page

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