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=============================================================================== Robb Kambic Unidata Program Center Software Engineer III Univ. Corp for Atmospheric Research address@hidden WWW: http://www.unidata.ucar.edu/ =============================================================================== ---------- Forwarded message ---------- Date: Tue, 08 Aug 2000 15:57:14 -0400 From: James D. Marco <address@hidden> To: Gilbert Sebenste <address@hidden> Subject: Re: Rpc.ldmd processes don't die right away in 5.1.2beta1... Hi ho, One quick note on this. Unix internal disk structures do not actually allow a file with an open filehandle to be deleted. Soooo, a product queue that is deleted while an update is in progress is not a fatal "file not found" error. As soon as the active process releases the link, the system will do the actual deletion. The consequences to the LDM stuff can be a profound loss of disk space if it is started and stopped too quickly, or, an active LDM process is killed in a critical region, sometimes resulting in a zombie process. (I haven't actually tried to intentionally damage it like this.) If you try to make a new queue, it may report a shortage of disk space even though the system reports enough room on the partition. If you have a large queue, wait at least 10-15 seconds before starting up again to avoid this. If your system is busy, wait longer. Caution dictates a system shutdown to fix this if it reports a zombie in the system process table (though, I've managed to successfully kill and recover from some Linux zombies.) jdm At 10:14 AM 8/8/00 -0500, Gilbert Sebenste wrote: >Hello Dave, > >> Gilbert, >> >> This is typical (and correct) behavior under Linux. I believe that >> these processes are finishing I/O before exiting, which is a good >> thing for the integrity of your product queue file. >> >> Dave Raymond > >I guess I hadn't noticed it before like this...however, I did stop the LDM >while it was still "catching up" from a re-start where I had deleted the >queue, so I guess it just must have been backlogged. > >With the new LDM and the pqsurf.conf entries suggested, I am now noticing >a significant performance improvement on my machine. Load average is >typically just over "1", now it runs at .8 or a little less. If there's >more activity on the radar and lots of people logging in, then it >skyrockets, but it's still below what I've seen it to be in the past. > >*************************************************************************** **** >Gilbert Sebenste ******** >Internet: address@hidden (My opinions only!) ****** >Staff Meteorologist, Northern Illinois University **** >E-mail: address@hidden *** >web: http://weather.admin.niu.edu ** >Work phone: 815-753-5492 * >*************************************************************************** **** > >