Applies to Data ONTAP 9 FlexGroup with NFS or CIFS workload FlexVol with NFS or CIFS workload Issue Elevated latency on NFS or CIFS FlexGroup or FlexVol, specifically on metadata (READDIR) operations.
Increased latency observed for "other" ops (specifically READDIR but can be seen on GETATTR and other metadata ops) on the FlexGroup parent Example: Normally a 6 node A800 cluster may see 10 GB/s writ...Increased latency observed for "other" ops (specifically READDIR but can be seen on GETATTR and other metadata ops) on the FlexGroup parent Example: Normally a 6 node A800 cluster may see 10 GB/s writes before hitting Data Processing latency, but throughput may only be 1-2 GB/s for writes Latency may be seen on a single constituent Reads or Writes can show a large increase in latency when there is a large increase in Read/Write workload within a single constituent.
Many long running READDIR/READDIR+ requests could be identified from a packet trace, it could take up to tens of seconds, or even hundreds of seconds in the worst case scenario [<node_name>: wafl_exem...Many long running READDIR/READDIR+ requests could be identified from a packet trace, it could take up to tens of seconds, or even hundreds of seconds in the worst case scenario [<node_name>: wafl_exemptxx: wafl.readdir.expired:error]: A READDIR file operation has expired for the directory associated with volume <volume_name>/@vserver:<vserver_uuid> Snapshot copy ID xx and inode <inode_number>.
Applies to ONTAP 9 FlexGroup Answer READDIR+ workloads can be very resource intensive in ONTAP, so in some cases there could be a performance impact to FlexGroup performance From an application standp...Applies to ONTAP 9 FlexGroup Answer READDIR+ workloads can be very resource intensive in ONTAP, so in some cases there could be a performance impact to FlexGroup performance From an application standpoint, it would be more beneficial to utilize LOOKUP operations vs READDIR+ where appropriate If you believe FlexGroup performance may be impacted, please consult the ONTAP 9 Performance Resolution Guide Additional Information NFSv3 RFC explaining operation types
