7 Troubleshooting Guidelines

This section includes some troubleshooting guidelines that may improve the performance of WebLogic Server on JRockit VE.

• Section 7.1, "Changing a VM's Memory Allocation and Disk Size"

• Section 7.2, "Using WLST to Reopen a Closed Log File"

• Section 7.3, "Where Do VM Core Dumps Go?"

• Section 7.4, "Why Do I Get a "Corrupted ELF Image" Error Message When Starting an Oracle VM Server?"

• Section 7.5, "Why Can't I Connect to a VM Using SFTP or SCP?"

7.1 Changing a VM's Memory Allocation and Disk Size

If you need more memory or a larger disk size for your VM(s), you can use the Image Tool to update the wlsve.xml file with the desired disk size and memory amount.

The command for setting the disk size is:

java -jar wlsveimagetool.jar -r vm.cfg set disk-size 1 "600 MB"

The command for setting the memory allocation is:

java -jar wlsveimagetool.jar -r vm.cfg set memory 1024

7.2 Using WLST to Reopen a Closed Log File

In this release, WebLogic Server VM log files on shared disks are read-only, and so they should not be modified. If some reason, a user does modify a log file at a shared location, you can use WLST to execute the ensureLogOpened() operation on the LogRuntimeMBean, which will attempt to re-open the log file.

For example:

connect('weblogic','weblogic','t3://localhost:7001)
serverRuntime()
ls()
cd('LogRuntime/AdminServer')
ls()
cmo.forceLogRotation()

where 'AdminServer' is the name of the server.

7.3 Where Do VM Core Dumps Go?

If you are suddenly running out of disk space on an Oracle VM server, then check in the /var/xen/dump/ directory, which is where the core dumps are stored by default.

7.4 Why Do I Get a "Corrupted ELF Image" Error Message When Starting an Oracle VM Server?

Check for unneeded dump files if you get the following error message when starting an Oracle VM server:

Error: (2, 'Invalid kernel', 'xc_dom_parse_elf_kernel: corrupted ELF image\n')

This typically happens when you have run out of disk space because there are many unneeded core dumps in the /var/xen/dump/directory. The error message is thrown when Oracle VM/Xen tries to place a copy of the JRockit VE ELF kernel image under /var/run/xend/, which it then tries to read. However, this fails because the /var partition is full.

7.5 Why Can't I Connect to a VM Using SFTP or SCP?

For security purposes, you must manually enable and target the SSHD service when using the packaged WebLogic Server VM image as a template for new or migrated domains. If you attempt to connect using SFTP or SCP and get repeated prompts for your password followed by a message, such as Error: The connection could not be made, then either of two things may be wrong:

• The SSH startup class is not deployed, or

• The SSH startup class is deployed, but not targeted to your server

See Section 4.2.2, "Deploying and Targeting the SSH Startup Class in a WebLogic Server VM."