Opening files in ONTAP CIFS shares takes longer when Qtree oplock is disabled
Applies to
ONTAP 9
Issue
- Opening files in specific CIFS shares are slow on Microsoft Windows clients for any file type (PDF, Microsoft Office files, etc.)
- Slowness when opening affected files may be exhibited via VPN and not via direct connection
- Opening specific files (xlsb, pptx, xlsx, docx) is significantly slower than others (txt, xls, pdf,..)
- Newly created SVMs sharing volumes via CIFS are not affected
- The issue is not spread across the volume rather it is particular share/qtree level issue only.
- No abnormal volume or protocol latency
- Follow below steps prior looking into qtree level options
- Run qos command to verify the volume latency is optimal and compare with historical data e.g. in OCUM
Example:qos statistics volume latency show -volume Volumename -vserver VStest
Workload ID Latency Network Cluster Data Disk QoS NVRAM
--------------- ------ ---------- ---------- ---------- ---------- ---------- ---------- ----------
-total- - 541.00us 125.00us 42.00us 84.00us 273.00us 0ms 17.00us
Volumename.. #### 182.00us 61.00us 0ms 78.00us 43.00us 0ms 0ms
-total- - 744.00us 430.00us 69.00us 79.00us 153.00us 0ms 13.00us
Volumename.. #### 180.00us 63.00us 0ms 77.00us 40.00us 0ms 0ms
-total- - 260.00us 62.00us 54.00us 85.00us 44.00us 0ms 15.00us
Volumename.. #### 192.00us 61.00us 0ms 84.00us 47.00us 0ms 0ms
-total- - 506.00us 77.00us 48.00us 211.00us 170.00us 0ms 0ms
Volumename.. #### 365.00us 61.00us 0ms 218.00us 86.00us 0ms 0ms - Check CIFS SVM level stats (this may be verified for SMB2 object as well):
statistics show-periodic -object cifs -instance VStest -node NodeA -counter cifs_ops|cifs_read_ops|cifs_write_op
- Confirm from above command if there is any delay at the storage level.
- If not, verify the Qtree level options because the issue only appears on specific shares