topic Re: Performance Adviser - How to find Average R/W I/O size in Network and Storage Protocols

Performance Adviser - How to find Average R/W I/O size

markryanwillis — Thu, 05 Jun 2025 06:21:02 GMT

I cannot seem to find this counter anywhere within DFM and have activated all special counters and have created custom views in Performance Adviser. I understand NetApp uses the 4k block for processing at the disk after it leaves the front-end ports, but need to determine what my I/O block-size mix is that hits my array. NetApp indicated the counter should be located under the "Target" counter, but seen nothing that looks like Average R/W Block I/O size. Maybe it's called something else? Anyone?

Re: Performance Adviser - How to find Average R/W I/O size

joker_morgan — Wed, 15 Aug 2012 14:37:47 GMT

Hi Mark,

Not sure if this is what you are after, but here goes. If you run NFS stat -d you get what the calls are and how many in each block size. By the way... you said that you have activated all special counters... can you send me any info on doing that? I am trying to measure average read and write latency for LUNs and when I try to build the view in the nmc I can see the counters that I want but it says that they are currently disabled.

Anyway... I have been looking into similar things lately and will post if I come across average block size.

Server nfs V3: (10472591952 calls)

null getattr setattr lookup access readlink read

719573 0% 3091300682 30% 9285901 0% 108448744 1% 196642215 2% 492878 0% 3294648946 31%

write create mkdir symlink mknod remove rmdir

3652494337 35% 8117853 0% 78572763 1% 10267 0% 0 0% 5110354 0% 169440 0%

rename link readdir readdir+ fsstat fsinfo pathconf

332190 0% 647367 0% 2678763 0% 10186353 0% 11942399 0% 780258 0% 10669 0%

commit

0 0%

Read request stats (version 3)

0-511 512-1023 1K-2047 2K-4095 4K-8191 8K-16383 16K-32767 32K-65535 64K-131071 > 131071

882835 1160717 1239622 1242489 27672958 245727834 10057425 2863000088 143761938 0

Write request stats (version 3)

0-511 512-1023 1K-2047 2K-4095 4K-8191 8K-16383 16K-32767 32K-65535 64K-131071 > 131071

2847114 1878793 2995831 4480958 66931547 38517381 5355888 3008322084 521167461 0

Re: Performance Adviser - How to find Average R/W I/O size

AGUMADAVALLI — Wed, 15 Aug 2012 14:58:13 GMT

From the Operations manager or latest oncommand core, download the NMC (NetApp Management Console) which will allow you to set the real time counters and can show the past analysis too.

thank you,

AK G

Re: Performance Adviser - How to find Average R/W I/O size

markryanwillis — Wed, 15 Aug 2012 17:58:08 GMT

AK G

Not sure if you understood what I had stated, but I'm using NMC 3.1

Re: Performance Adviser - How to find Average R/W I/O size

markryanwillis — Wed, 15 Aug 2012 19:55:43 GMT

Enable showing of diagnostic counters in DFM: dfm option set perfAdvisorShowDiagCounters=yes

Restart DFM and then create your custom views, charts, etc.

I think there should be a specific counter within DFM that would capture this as it's a pretty standard metric as far as I can tell. Using NFS stat -d does not provide me the average read/write I/O block size coming in from attached FC-host, so not sure that will work for all around analysis of SAN throughput as well as other NAS protocol's such as CIFS I/O request.