Performance Decreases on NetApp hosted Disk Library mount path when space usage exceeds 85%

Backups to a disk library using NetApp hosted mount paths will experience performance degrade as used disk space exceeds 85%

Symptoms

Writes to NetApp hosted mount path slow as used capacity exceeds 85%

Causes

This is a known issue (Bug 588941) with NetApp's Data ONTAP versions prior to 8.0. For more information, see http://support.netapp.com/NOW/cgi-bin/bugrellist?bugno=588941.  NetApp Login credentials required.

Resolution

Upgrade to the most recent version of NetApp's Data ONTAP. Contact your NetApp vendor to make sure that the most recent version of Data ONTAP is recommended for your NetApp device.

If you cannot upgrade to the most recent version of NetApp’s Data ONTAP, set the reserve space thresholds on the NetApp devices that are managed by Data ONTAP to 15%. Monitor those devices to make sure that disk usage does not exceed 85%.

1. From the CommCell Browser, expand to Storage Resources | Libraries | <Library>.
2. Right-click the appropriate mount path, and then click Properties.
3. Click the Allocation Policy tab.
4. In the Space Allocation section, select Do not consume more than n GB, and then enter a value that is 85% of the total disk space.
5. Click OK.