platform like Celerra will "ping" back the client every minute to make sure the client is still there, if the client is not there after so many re-tries the session is closed.  This activity will keep firewall sessions alive, now on Isilon (at least on 6.5), this "ping" back process is done every 2 hours (default value).  If you have firewalls that close inactive sessions after 30 minutes you can see how that could lead to the problem you are describing. I open an Excel spreadsheet and go away to lunch. In 30 minutes my firewall kills the session because there has not been any activity. I come back from lunch and when i tried to work on my spreadsheet it says that the file is locked and i end up having to save into a temporary file etc. Two hours later Isilon decides to "ping" back to see if you are still there but gets nothing because firewall killed that session 1.5 hours ago.  When i captured traffic between Celerra and my clients and saw that Celerra was pinging back every 1 minute ( i know very chatty), i decided to lower the "ping" time on Isilon to 5 minutes. So isilon will "ping" the client every 5 minutes and ask him "are you there?", client would say "yes i am still here", this process would keep the firewall session alive and everyone was happy [IMAGE]  The current setting can be reviewed with the following command  isi_for_array -s 'sysctl net.inet.tcp.keepidle'  To set the value --  isi_sysctl_cluster net.inet.tcp.keepidle=300000  (5 minutes, value in milliseconds)  The next sysctl that would be of interest is the ping interval with is currently set at 75000 (75 Seconds).  The cluster will send 8 pings at a 75 second interval resulting in a 5 minute window for the client to respond.    To view the setting -- isi_for_array -s 'sysctl net.inet.tcp.keepintvl'
So we have a problem with a common scenario throughout our organization. User is working on open files (docs, spreadsheets, etc) through a mapped SMB drive via a Windows client. User leaves for lunch or leaves for the day, When they get back to their workstation, they are unable to save their open files. Error indicates that file is in use. User needs to save file to desktop, then log off, log back in, then overwrite desktop file with the file originally opened from share to save updated version.  Problem seems to be that their session has timed out with the open files still being open. When they log back in, connection to Isilon creates a new session which is different from the one that originally opened the file thus Isilon believes that the file is in use by another even though the user is the same.  Anybody else run into this?
Problem with user session, timeouts, and open files.