SAN Bandwith in lpar2rrd only half after AIX update

skol

Hello

We have lpar2rrd 7.20 and lpar2rrd-agent-7.20-1.
Since we update the AIX to 7.2 TL5 SP2 (from TL3) the "SAN"-tab shows about half of the bandwith.
"SAN IOPS" and "SAN RESP" looks ok.
nmon shows the correct bandwith (double of lpar2rrd)
Therefore I assume the collection is not working properly.

Someone else with the same experience?

Regards Stefan

Pavel

Hi,

provide us:

1.

date

fcstat <fcsX adapter> | grep Bytes

sleep 300

fcstat <fcsX adapter> | grep Bytes

2. screenshot ofthe SAN graph from that time period, zoom it on that time

skol

Hi Pavel

I made with ndisk64 IO on the disk.

Here the output of your commands:

/root # date; fcstat fcs0  | grep Bytes; sleep 300; fcstat fcs0  | grep Bytes

Fri Aug  6 16:21:19 CEST 2021

  Input Bytes:  35051667

  Output Bytes: 1503871560

  Input Bytes:  47163539

  Output Bytes: 318964296

This are about 3 MB/s on fcs0. It matches the data in lpar2rrd.
But in nmon it looks like this during the transfer.

Disk-Adapter-I/O 

Name          %busy     read    write        xfers Disks Adapter-Type          

vscsi1          0.0      0.0      0.0 KB/s     0.0 1     Virtual SCSI Client A 

vscsi0          0.0     32.0      0.0 KB/s     7.0 1     Virtual SCSI Client A 

fcs3           68.9      0.0  81795.8 KB/s   159.8 1     Virtual Fibre Channel 

fcs2           65.9      0.0  81795.8 KB/s   159.8 1     Virtual Fibre Channel 

fcs1           75.9      0.0  81540.1 KB/s   159.8 1     Virtual Fibre Channel 

fcs0           80.9      0.0  81028.9 KB/s   159.8 1     Virtual Fibre Channel 

TOTALS  6 adapters      32.0 326160.6 KB/s   646.0 2     TOTAL(MB/s)=318.5  

It is about 80 MB/s.

skol

now I see the second number is even smaller than the first in "Output Bytes".
I have problems attaching a printscreen. But there it shows about 2.5 MB/s average.

skol

Pavel

Hi,

it is something we aready seen, pls report it to AIX support, we just present what we get from fcstat.

BTW there is some apar, I am not sure if it is related or not

https://www.ibm.com/support/pages/apar/IJ32635