Troubleshooting the SAM-FS Stager

When investigating a problem staging files, it is important to determine if the problem is limited to one file or is persistent and affects many files. One way to determine if the problem affects one file or many is to monitor the samu "n" display. This display shows staging activity. Once you are in the samu "n" display, press the Control key and tap "k" The display now shows the file being staged.

If you find that just one file or just the files on one VSN are not staging, you should check the sls -D display for that file to see if the archive copies are marked damaged. If only one archive copy is damaged, use the undamage to undamage archive copy, then try the stage again. I all archive copies are damaged, the additional step of undamaging the file will be necessary.

If attempts to undamage archive copy does not resolve the problem, you should then attempt to stage other archive copies. If no other archive copies exist, use the disaster recovery techniques described in the Appendix of the SAM-FS System Administrator's Guide to retrieve the file.

Files not staging properly can generally be traced to one of several conditions:

  • Is the file system full? Is there room in the file system to stage the file?
  • Are archive copies marked damaged? Is the media bad?
  • Is the VSN listed in a robot?
  • Is a drive available for staging?
  • Is the drive reporting hardware problems?
  • Is excessive recycling occurring?

Checking Stager Log files for possible errors reported

  • Log files related to the stager process that may be helpful in problem determination are:
    • /var/adm/sam-log
    • /var/adm/messages
    • /var/opt/SUNWsamfs/trace/sam-archiverd
    • /var/opt/SUNWsamfs/trace/sam-stagerd
    • stager log file (configurable)
    • recycler log file (configurable)
  • The samu cli display may also provide some assistance.
    • samu "w" display

Supporting Documentation and Additional data collection

  • Enable daemon tracing
  • Enable stager logging