SnapMirror Sync(SM-S) primary volumes has high latency due to volume bursty workload

Last updated
Save as PDF
Share
1. Share
2. Tweet
3. Share

Views:: 179

Visibility:: Public

Votes:: 0

Category:: ontap-9

Specialty:: perf

Last Updated:

Applies to

ONTAP 9
SnapMirror Sync(SM-S)

Issue

The client reports very high write times on SM-sync primary volumes from SM-Sync from QOS command.

cluster::> qos statistics workload latency show -vserver SVM1 -volume vol1
Workload            ID    Latency    Network    Cluster       Data       Disk    QoS Max    QoS Min      NVRAM      Cloud  FlexCache    SM Sync         VA
--------------- ------ ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ----------
vol1              4040    54.16ms    09.72ms        0ms    57.00us   14.00us         0ms     1.00us        0ms        0ms        0ms     44.44ms       0ms
vol1              4040    58.16ms    09.72ms        0ms    57.00us   14.00us         0ms     1.00us        0ms        0ms        0ms     48.44ms       0ms

The client may report slow copy/write operation

$ time echo '123' >/cbsrun/test1.txt;time echo '123' >/cbsrun/test20220401/test2.txt;

real    0m1.08s
user    0m0.00s
sys     0m0.00s

real    0m3.26s
user    0m0.00s
sys     0m0.00s