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Summary



Backups to DISKDIRECTORY devices are slow.

Symptoms



Backup starts with no errors and good performance. As the backup progresses, performance begins to degrade to the point that the job appears to be hung.

 



Resolution



Windows device servers with configured DISKDIRECTORY devices can experience degrading performance as the size of the DISKDIRECTORY files grows. To work around this problem, the SSDSKMAX option has been implemented to limit the size of the DISKDIRECTORY files. SSDSKMAX should be assigned an integer representing the number of writes allowed to a DISKDIRECTORY file. Once this limit has been reached, Backup Express will simulate end of tape and request the next volser.

 

The procedures as follows:

  1. Verify that the device server updates have been applied.
  2. Edit registry. Modify/create SSDSKMAX key located at the following registry path:
    HKEY_LOCAL_MACHINE\Software\Syncsort\BackupExpress\<nodename>\0
  3. Set SSDSKMAX to the number of writes allowed to a DISKDIRECTORY file. By default, writes are 32kb in size.
  4. Restart DPX services on device server.

 

This behavior has been addressed in a DPX Maintenance Update. The update can be automatically installed via the DPX Software Update System user interface or can be manually downloaded from the Catalogic Software Online Support site (mysupport.catalogicsoftware.com). Check the Software Update Release Notes for your DPX release referencing Issue ID 25.