4.2. GFS2 File System Hangs and Requires Reboot of One Node

If your GFS2 file system hangs and does not return commands run against it, but rebooting one specific node returns the system to normal, this may be indicative of a locking problem or bug. Should this occur, gather the following data:
  • The GFS2 lock dump for the file system on each node:
    cat /sys/kernel/debug/gfs2/fsname/glocks >glocks.fsname.nodename
  • The DLM lock dump for the file system on each node: You can get this information with the dlm_tool:
    dlm_tool lockdebug -sv lsname.
    
    In this command, lsname is the lockspace name used by DLM for the file system in question. You can find this value in the output from the group_tool command.
  • The output from the sysrq -t command.
  • The contents of the /var/log/messages file.
Once you have gathered that data, you can open a ticket with Red Hat Support and provide the data you have collected.