topic Re: ls command hangs during telnet only in Operating System - HP-UX

ls command hangs during telnet only

Gerald Taylor — Tue, 06 Jan 2004 08:50:24 GMT

I have an interesting problem. I have telnet and ssh running on the system when I telnet to the system I can log in successfully but the first time I run 'ls' the command hangs. If I use ssh to the system the same directory comes back perfectly. I don't see any errors in syslog and I have bounced telnetd and inetd services. Any suggestions?

Gerald

Re: ls command hangs during telnet only

Gerald Taylor — Tue, 06 Jan 2004 09:00:00 GMT

I apoligize I have discovered that it is not limited to the ls command 'bdf' and 'who' also hang. I am suspecting a problem with the telnet daemon.

Re: ls command hangs during telnet only

Olivier Drouin — Tue, 06 Jan 2004 09:02:34 GMT

or your terminal, what are you using ?

Re: ls command hangs during telnet only

Elena Leontieva — Tue, 06 Jan 2004 09:05:06 GMT

Gerald,

Check out this thread:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=42444

HTH, Elena

Re: ls command hangs during telnet only

Elmar P. Kolkman — Tue, 06 Jan 2004 09:15:46 GMT

Also check how ls is called. Perhaps the ssh session or the telnet session uses aliases for ls... Or different paths. You can find out by running:
which ls
You could also force both sessions to run the same command, by typing:
/bin/ls
in both sessions.

Are you using pipes or things like that, or are you just running ls straight to your session?

Have you tried to redirect the output of the commands to a file?

Re: ls command hangs during telnet only

Gerald Taylor — Tue, 06 Jan 2004 09:16:21 GMT

I am able to ssh (secure shell) into the system and the commands return successfully. A bdf shows no file systems are full. TERM is set to vt220 using CRT or secure CRT.

Gerald

Re: ls command hangs during telnet only

Gerald Taylor — Tue, 06 Jan 2004 09:19:56 GMT

ls > temp.out

is successful. Both sessions use /usr/bin/ls. I am unsure why 'ls > temp.out' works but just using 'ls' hangs. Does this mean my terminal settings are off?

Gerald

Re: ls command hangs during telnet only

Elmar P. Kolkman — Tue, 06 Jan 2004 09:33:47 GMT

Have you looked in the directory?
You could try:
ls | cat -tv | more
Look for things like ^Q, ^S or other escaped control characters.

Sometimes special characters might hang your system, for instance -Q and -S are stop and start handshake characters. In output they might halt your output, untill the other side of the connection sends the start byte again.

Re: ls command hangs during telnet only

Gerald Taylor — Tue, 06 Jan 2004 09:54:33 GMT

ls | cat -tv | more

works fine but I do not see any special characters in the directories. I am able to cd into different directories but the hang occurs on all directories.

Gerald

Re: ls command hangs during telnet only

Bill Hassell — Tue, 06 Jan 2004 22:42:41 GMT

Since bdf a well as ls hangs, I would strongly suspect NFS problems. Are you using NFS and if so, are any of them dead?

Re: ls command hangs during telnet only

T G Manikandan — Tue, 06 Jan 2004 23:06:05 GMT

Check two things

1.check for NFS mounts
2.move out the initialization files respective to your shell .profile .login .cshrc files and then try again.It could have some terminal settings.

Is that specific to only one user or all users

Re: ls command hangs during telnet only

Steven E. Protter — Tue, 06 Jan 2004 23:32:51 GMT

NFS hang is likely the cause here, though it should show up on ssh as well.

Another possible cause is some kind of issue with a missing disk. If course this should show up in syslog, but if it went dead fast say right before you cleared syslog you might miss it.

Something to look in, possibl missing disk.

NFS or network is more likely.

SEP

Re: ls command hangs during telnet only

Elmar P. Kolkman — Wed, 07 Jan 2004 01:46:10 GMT

You might try the default windows telnet client and set your TERM variable to vt100. That helps to rule out it's a client/terminal emulator issue.

Re: ls command hangs during telnet only

Balakumar M — Wed, 07 Jan 2004 01:54:55 GMT

Hi,
The most possible cause which makes "ls" to hang are,
1) /tmp or /var file system full
2) NFS mount point problem
3) linked file problem in the respective directory..

Best regards,
Bala

Re: ls command hangs during telnet only

Gerald Taylor — Wed, 07 Jan 2004 02:20:06 GMT

Thanks for the responses I have tried all of the above and the problem still exist. Still open to suggestions. I should not that the bdf hangs but it is not limited to bdf command. Also all the commands work if we redirect them to a file. example:
bdf > bdf.out

will work but
bdf

will hang, also if I ftp to another system and try 'ls' this will hang also. Makes me think this is a communication issue I just don't know the fix.

Gerald

Re: ls command hangs during telnet only

Sanjay Kumar Suri — Wed, 07 Jan 2004 02:35:37 GMT

Dear Gerald

As I understand output to terminal is failing whereas output to a file is working.

Check if terminal device files are correctly defined.

sks

Re: ls command hangs during telnet only

Gerald Taylor — Wed, 07 Jan 2004 13:24:44 GMT

We are still having the problem but we have found the commands work from the "lan" and fail when used over the "wan" Currently we have a strong suspicion that the frame relay is causing problems. Perhaps there is a network guru that has seen something like this before?

Gerald

Re: ls command hangs during telnet only

Chris Hulihan — Thu, 08 Jan 2004 12:55:41 GMT

Did you check your terminal's "enter" key setting (depending on which terminal program you're using)? Or did you try a different terminal program to see if it does the same thing? The problem may not be on the system that you're running commands are, it could just be the telnet program itself.

Re: ls command hangs during telnet only

Gerald Taylor — Thu, 08 Jan 2004 13:00:29 GMT

We have fixed the problem, it was the WAN connection between the sites that caused the problem. Thanks everyone for all your help.

Gerald