Troubleshooting CIFS Latency - Single volume readdir workloads with high latency
Applies to
- ONTAP 9
- Data ONTAP operating in 7-Mode
- Slow CIFS Home Directories
- Slow VDI (Hyper-V) or Citrix Home Profiles using folder redirection.
Issue
- Slow loading of a home directory or VDI folder in Citrix due to thousands of user folders in the root of a CIFS share
- High latency is seen:
- In the
Datacolumn ofqos statistics volume latency show - Data Processing delay center of AIQUM in the volume view of Cluster components
- High "other" latency (SMB2
Create/Open, Close, Readdir, Lookupoperations)
- In the
- Example:
Workload ID Latency Network Cluster Data Disk QoS NVRAM
--------------- ------ ---------- ---------- ---------- ---------- --------- --------- ---------
-total- - 136.49ms 99.00us 70.00us 136.17ms 153.00us 0ms 0ms
vserver1_vol1.. 4201 206.05ms 130.00us 0ms 205.88ms 44.00us 0ms 0ms
vserver5_vol8.. 7704 1309.00us 351.00us 1.00us 834.00us 114.00us 0ms 9.00us
-total- - 140.29ms 103.00us 75.00us 139.94ms 174.00us 0ms 0ms
vserver1_vol1.. 4201 379.03ms 127.00us 0ms 378.73ms 175.00us 0ms 0ms
vserver5_vol8.. 7704 2.02ms 309.00us 1.30us 1820.00us 105.00us 0ms 9.00us