First one sounds like you're looking at total I/O on the controller. This is going to include all of the backend traffic such as shifting data between tiers, fast track, etc and any ongoing raid scrubs or data migration. You might to well to look at the I/O for the individual back end ports as a mixed tier system will have different thresholds per disk class. Setting a threshold of 8000 IOPS on the back end won't do much if all of the traffic is on a SATA shelf that blows up around 2000. I think CoPilot can provide some guidance with setting up decent alerting.
Second sounds like a common graphing error. If you've ever used software like PRTG you'll rember that as you increase the sample size you lose resolution. Quite frequently I've seen graphs drop off peaks and take a more averaged approach.
hallidayr
48 Posts
0
September 24th, 2012 08:00
First one sounds like you're looking at total I/O on the controller. This is going to include all of the backend traffic such as shifting data between tiers, fast track, etc and any ongoing raid scrubs or data migration. You might to well to look at the I/O for the individual back end ports as a mixed tier system will have different thresholds per disk class. Setting a threshold of 8000 IOPS on the back end won't do much if all of the traffic is on a SATA shelf that blows up around 2000. I think CoPilot can provide some guidance with setting up decent alerting.
Second sounds like a common graphing error. If you've ever used software like PRTG you'll rember that as you increase the sample size you lose resolution. Quite frequently I've seen graphs drop off peaks and take a more averaged approach.