Lower than expected performance while utilizing a single volume
Applies to
ONTAP 9
Issue
- Lower than expected performance while utilizing a single volume
- Latency or slowness is seen in any operating system (Windows, Mac OS, Linux, ESX, etc.) or application (Office, Oracle, ESXi, Hyper-V, etc.)
- High latency on a volume with low CPU utilization.
Example:
- The output of command
sysstatshows a low Avg CPU utilization - The output of
wafltoponly shows the high i/o on vol1 - vol1 takes the majority of Ops
- No high latency from other volumes
CPU Utilization Percent
Application Total STRIPE LAST_STRIPE STRIPEGROUP VOL_LOG VOL_VBN_RANGE VBN_RANGE VOL_VBN VBN VOL AGGR_VBN_RANGE AGGR_VBN AGGR SERIAL XCleaner
----------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------
aggr1:vol1:cifs:WAFL_SPINNP_WRITE: 54 0 0 0 0 0 0 0 0 0 29 0 0 0 14
aggr1:vol2:cifs:WAFL_SPINNP_WRITE: 2 2 0 0 0 0 0 0 0 0 0 0 0 0 0
aggr1:vol3:cifs:WAFL_SPINNP_WRITE: 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0
aggr1:vol4:cifs:WAFL_SPINNP_WRITE: 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0
...
I/O utilization
---------MB Read---------- ---------MB Write--------- --------IOs Read---------- --------IOs Write---------
Application MB Total Standard ExtCache Hybrid Standard ExtCache Hybrid Standard ExtCache Hybrid Standard ExtCache Hybrid
----------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- --------
aggr1:vol1:cifs:WAFL_SPINNP_WRITE: 2558 9 0 0 2549 0 0 0 0 0 1287 0 0
aggr1:vol2:cifs:WAFL_SPINNP_WRITE: 12 0 0 0 12 0 0 0 0 0 3 0 0
aggr1:vol3:cifs:WAFL_SPINNP_WRITE: 7 0 0 0 7 0 0 0 0 0 1 0 0
aggr1:vol4:cifs:WAFL_SPINNP_WRITE: 5 0 0 0 5 0 0 0 0 0 1 0 0
Cluster::> node run -node node1 -command sysstat -x 1
CPU NFS CIFS HTTP Total Net kB/s Disk kB/s Tape kB/s Cache Cache CP CP_Ty CP_Ph Disk OTHER FCP iSCSI FCP kB/s iSCSI kB/s
in out read write read write age hit time [T--H--F--N--B--O--#--:] [n--v--p--f] util in out in out
13% 261 3 0 2927 222768 258592 104 0 0 0 12 100% 0% 0--0--0--0--0--0--0--0 0--0--0--0 1% 2663 0 0 0 0 0 0
15% 403 6 0 3040 255451 255197 116 0 0 0 12 100% 0% 0--0--0--0--0--0--0--0 0--0--0--0 2% 2631 0 0 0 0 0 0
5% 348 10 0 811 6094 9894 232 24 0 0 12 100% 0% 0--0--0--0--0--0--0--0 0--0--0--0 2% 453 0 0 0 0 0 0