On Fri, May 21, 2010 12:34, Xymon User in Richmond wrote:
My apologies to all for the original post of this, which had In-Reply-To and other headers that apparently caused some confusion. Here's a clean post.
I need to suppress checking of CIFS mounts to avoid piling up IO-blocked processes when a mount hangs. What hobbit file/program controls the "df" command used for the disk check? The DF= and DFCMD= lines in hobbitclient.cfg are commented "DF,DFCMD and PS are for compatibility only, NOT USED by the Hobbit client", and sure enough when I add "-xcifs" to those lines I still get the CIFS mounts after restarting the hobbit-client service.
Found the df command in client/bin/hobbitclient-linux.sh, all options hard-coded. How strange to do that after setting variables in a config script. Thank goodness for the "move along, nothing to see here" comment or I'd still be trying to figure out what was wrong with my hobbitclient.cfg.
To fill in the scenario, the df "-l" option does NOT suppress checking CIFS (Windows) remote mounts, there's a bug in mount.cifs or something under it that makes such mounts "hang" on a Linux machine if Windows is rebooted while the mount is live, and until you reboot the Linux machine, any process that tries to access the mount blocks on i/o. It only affects one of our applications when the mounts hang, but the server often locks up from all the hobbit processes blocked overnight. I'm still trying to figure out how to write a check to detect the hung mount condition. It was previously suggested to check the share via SMB, but the fact that it's currently available is unrelated to the question of whether a Linux box has a hung mount of it. I guess I need to figure out how to launch a df or some such and check whether it blocked on i/o.