Some new users running very slowly in local lab setting

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All, forgive me if this question is too trivial, but I have been forced as an untrained professional into a sysadmin role for a local-network classroom lab on my campus, and my IT department claims no knowledge of anything Linux related.

I recently had a multiple drive failure in my RAID, necessitating a reinstallation of RHEL on my server. I had to recreate the user accounts, and have discovered that some of the new accounts appear to be running very slowly, while others seem to run fine. The output of top doesn't indicate that there are any runaway processes slowing things down.

My configuration has always been to use NIS to distribute user accounts in the 10 seat lab, and NFS to share the /home directory among the client computers. I believe that these systems are running properly, based on checking rpcinfo and service nfs status on client and server. Plus, df shows the mount is working, and I've not seen any NFS errors. NIS seems to be working, else I wouldn't be able to login. But, in the affected accounts, it takes 30 seconds to open a terminal window, and roughly the same amount of time to switch between windows. In others, everything seems to run normally. I created all of these accounts at the same time, and new accounts created this morning to test the setup all have this slow-running issue.

Can anyone please suggest where else I should look for errors? Could it be a network hardware issue to affect different users differently? Time is, as usual, of the essence as I am expecting a class to try to use this lab later today, and I have to fit my work in the lab in around my own course load.

Thanks for any advice you could provide,
Todd
SUNY Oneonta

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Hi Todd, welcome to the community. All questions are welcome, but if time is of the essence, it might also be worth opening a support case to guarantee that you get an answer as quickly as possible.

That said, I'm sure some folks here would be able to offer suggestions for where to start troubleshooting.

Just a guess (need more information to give you better than a guess) but, if what you're describing is that you've got slowness with the workstations' graphical desktops, it's entirely likely that you're having name resolution issues. X-based applications tend to perform poorly/haltingly if name resolution isn't working. 30 seconds is the default timeout for name resolution failures - which would seem to jibe with the symptoms you're describing. Basically, the X application (GDM, xterms, any other launched applications) would make a name lookup call for the display-client (the afflicted workstations), wait for the call to either return a value or give a resolution-failure, and only then proceed with the rest of the X application's launching tasks.

what other information would you need from me to help diagnose this? I generally have time to work on my lab on Thursday and Friday (everything else is teaching and meetings). I can try to gather that information and report back.

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