core.dmp files hogging space on C:\
The files are labeled "core.********.******.****.****.dmp"
The ****** portion seems to be a date/time stamp for when the file was created.
The files are stored in the following directory...
C:\IBM\Websphere\AppServer\profiles\AppSrv01.
Can anyone tell me about these files? They average about 12-14 GB in size.
Thanks!
3 answers
These files in huge in size , depending on how much heap is configured and how much was used when the process Ran out of memory,
I would expect your server not to work if that happens.
Otherwise check Xdump argument to see if has argument to write system dump when ever you take a JAVA core.
Comments
These are the Generic JVM arugments I have set in Websphere Admin Console....
-Xmx12g -Xms12g -Xmn3g -Xgcpolicy:gencon -Xcompressedrefs -Xgc:preferredHeapBase=0x100000000 -XX:MaxDirectMemorySize=1G -Dlqe.config.location=file:///C:\IBM\JazzTeamServer6.0.1\server\conf\lqe
I don't see anything about "-Xdump". Can you tell me where to look for that argument? Thanks!
If you're using WAS 8.5.5, it by default creates a system dump when the first OOM occurs.
http://www.ibm.com/support/knowledgecenter/SSAW57_8.5.5/com.ibm.websphere.nd.doc/ae/ctrb_java626.html
Before you decide to remove the dump files or change JVM settings, have a look at the first 10 lines of the javacore* files, and you should know why these dump files were created. OutOfMemory in the Java "heap space" can sometimes be easily resolved by bumping up the heap size, but other errors can be complicated and require further investigation to get a proper solution.
They are often accompanied by javacores, heapdumps, snapdumps etc. All these files can be used to diagnose problems within the WebSphere server so if you do move them you should keep them together.
Comments
Some of them are older (from 2015). Some of them are recent, including today, 2 days ago, and 5 days ago. There are also javacores and heapdump files that have similar timestamps so I will try to keep those files together (the recent ones anyway).
Is this a setting I have on somewhere in Websphere? Can I turn off the core dumps, javacores, and heapdumps?
It seems the timing of these dumps has to do with reboots of my CLM server. Either during shutdown, or bootup, something is crashing and causing these dump files.
I think the -Xdump option can do that but it's probably not a good idea to prevent these files from being created; without them you won't be able to determine the cause of the crashes and if you ever decide to open a PMR the WebSphere support team will need them to begin diagnosing the issue. As mentioned in another answer; the likelihood is your server is running out of RAM so you'd be better served in determining why the dumps are being taken.
I understand that the location that these files are written to can be controlled by environment variables so if space on the C:\ drive is at a premium you could consider redirecting them to a different drive instead.
There are a number of resources to help troubleshoot WebSphere crashes on-line from IBM and elsewhere. These links from IBM and StackOverflow look particularly useful:
http://www-01.ibm.com/support/docview.wss?uid=swg21181068
http://www-01.ibm.com/support/docview.wss?uid=swg21393547
http://stackoverflow.com/questions/7361233/how-to-analyse-websphere-core-dmp-file-and-snap-trc-files
http://stackoverflow.com/questions/19152376/how-to-stop-creating-heap-files-java-core-files-which-are-creating-in-jvm-insta