Skip to main content
NetApp Knowledge Base

CONTAP-120558: Time to Live (TTL) of CNAME DNS record cached in ONTAP can be invalid

  1. Last updated
  2. Save as PDF
Views:
202
Visibility:
Public
Votes:
0
Category:
ontap-9
Specialty:
nas
Last Updated:

Issue

  • Disks will report 100% utilization and higher latency will be seen.
    • Could be a subset of disks or all disks on node.
      cluster::*> run -node node1 statit -b
      ... (wait 30 seconds)

      cluster::*> run -node node1 statit -e
      ...
      disk ut% xfers ureads-chain-usecs writeschain-usecs cpreads-chain-usecs greads-chain-usecs gwrites-chain-usecs
      /data_aggr1/plex0/rg0:
      0a.11.1 10 23.42 0.00 .... . 11.21 61.56 133 12.21 57.15 50 0.00 .... . 0.00 .... .
      0a.10.1 11 23.80 0.00 .... . 11.66 59.25 147 12.14 57.37 55 0.00 .... . 0.00 .... .
      1a.12.1 100 158.69 120.29 5.43 2299 10.26 34.39 553 28.15 9.93 839 0.00 .... . 0.00 .... .
      0a.11.2 100 156.09 118.85 5.39 2253 9.96 34.97 553 27.28 10.05 794 0.00 .... . 0.00 .... .

      cluster::> qos statistics volume latency show -vserver svm1 -volume vol1
      Workload         ID         Latency    Network    Cluster    Data         Disk    QoS Max   QoS Min     NVRAM 
       --------------- -------- --------- --------- --------- ------- ------ -----------  ----------- ----------
      total              -       4.71ms    185.00us      7.00us   468.00us     4.04ms  0ms        0ms        11.03s
      vol1-wid32140   32140   22.22s     86.00us    125.00us  904.00us 321.11ms  0ms        0ms        16.34s 
  • DNS TTL values may report incorrectly.
    • Azure best practice of page blobs is 60 second TTL.
      cluster::*> name-service cache hosts forward-lookup show vserver <cluster_name>
      (vserver services name-service cache hosts forward-lookup show)
      IP Address IP Create
      Vserver Host Protocol Family Address Source Time TTL(sec)
       --------- -------- -------- ------- -------------- ------- ---------- --------
      cluster pageblobhost.blob.core.windows.net Any Ipv4 dns 53050
      20.1.2.3 11/28/2023 09:22:43
      cluster pageblobhost.blob.core.windows.net Any Ipv4 dns 25462
      20.1.2.3 11/28/2023 09:26:40
      ...
      Note: Make sure the SVM name matches cluster name before the prompt (::*> in this case)

 

Sign in to view the entire content of this KB article.

New to NetApp?

Learn more about our award-winning Support

NetApp provides no representations or warranties regarding the accuracy or reliability or serviceability of any information or recommendations provided in this publication or with respect to any results that may be obtained by the use of the information or observance of any recommendations provided herein. The information in this document is distributed AS IS and the use of this information or the implementation of any recommendations or techniques herein is a customer's responsibility and depends on the customer's ability to evaluate and integrate them into the customer's operational environment. This document and the information contained herein may be used solely in connection with the NetApp products discussed in this document.