OnCommand Storage Management Software Discussions

Monitoring Loop Performance

Can someone point me to documentation outlining how to monitor disk loop performance?  I'm currently using OM 4.0 but I don't see any objects that give me this info.




Re: Monitoring Loop Performance

HI Jamey,

Are you talking about the physical loop connectivity between the head and disk shelf ?

If so we don’t discover those objects, so you won’t be able to do it.



Re: Monitoring Loop Performance

Thanks for the reply Adai.  Yes, that is exactly what I am talking about.

So there is no way of monitoring this at all?  Or there is no way currently to monitor it in OM?



Re: Monitoring Loop Performance

As Far As I Know not in OM, I am not aware of other tools.



Re: Monitoring Loop Performance

The doc

Performance Management
Monitoring And Analysis

byAkshay Bhargava
Mukesh Nigam
And a bit.. Alain Geenrits


Bottleneck: FC-AL Loop have throughput limitations

  • Each 2Gbit ESH loop can support up to 170-180MB/s


  • High response times to requests on one or more volumes
  • Inability to add more load to one or more volumes
  • RAID reconstruction / scrub

Diagnosis: High disk utilization can indicate loop limits
Use statit to monitor disk utilization
Loop Saturation - If disk utilization is >70% but low disk tput(67 * 31.5 * 4K = 8 MB/s per disk) *and* high data transfer rates on a loop

disk ut% xfers ureads--chain-usecs writes--chain-usecs
0b.16 0 0.03 0.02 10.00 5250 0.01 10.00 0
0b.17 97 66.91 66.90 31.54 1774 0.01 10.00 0
0b.18 96 67.06 67.05 31.49 1552 0.01 10.00 0
0b.19 95 66.99 66.98 31.54 1472 0.01 10.00 0
0b.20 94 67.05 67.04 31.48 1453 0.01 10.00 0

You maybe able to create a customer report in OM with this method.

Hope it helps