Hi,
I can suggest some pointers as I have dealt with latency issues on NetApp filers lately. As I see this is a 7-mode Filer, so you may need more efforts to pin down the root cause(s). In cDOT the way latency is reported is completely changed the game and made it much easier for the storage admins to determine at which layer the latency is building up.
For 7-mode filer and NFS protocol, I will look at following items first, later we can delve into other protocol layer latencies.
1) Whats the aggregate capacity where this volume is hosted?
output of : filer>df -Ah
2) Whats the Avg CPU usage on this FILER, along with Peaks?
Grafana can give you this figure / Or simply run
filer>sysstat -m 1 [for 2-5 minutes] if the CPU is too high then stop it after a minute.
3) Collect the disk statistics
filer>privs set diag
filer>statit -b
let it run for a 1 minute
filer>statit -e
All these information is good enough to come to some conlcusion, plus we need to remember - Is this NFS vol presented as ESX Datasotre, in that case the Avg IO size is between 50 to 64KB. And, if you have a 1500-mtu environment, it means you will need :
IO Size = 64K
1500-mtu = Actual payload could be up to = 1460bytes = 1.4k
= > Total packets required before you complete a single IO => 64/1.4 = 45 Packets on avg for an acknowledgement. For NFS applications that read/write with smaller IOs, may have low latency despite other factors such as disk/cpu usage high.
Let us know the output of those items.
Thanks,
-Ash