Solution Manager Monitoring - proper monitoring metric for disk performance
We have setup Solution Manager with some templates to monitor our SAP systems health. One of the areas we did this setup was in the Operating System space, where we had used the Average Service Time per Disk with the standard threshold of 100 ms. But what we are seeing is a huge number of occurrences happening several times per day. When looking in details to that, I noticed the messages happens almost all of the times for internal disks. As we are running in SuSe Linux 11 Enterprise, and the disks are all setup with Device Mapper, all of them appears as dm-XX no matter it is a storage disk or a internal one, so we can´t have distinguish between them.
Based in the current scenario I started to work with our Unix team to identify any bottleneck on disks, but so far we were unable to find any issue looking at the server performance stats.
Per what I could see in the Solution Manager this metrics is collected from SAPOSCOL:
"This is the average service time in milliseconds for I/O requests. This metric is retrieved from the saposcol running on the host."
My question here is how the SAPOSCOL get that information from OS, because I looked at IOSTAT documentation and it says the "Service Time" metric (svctm) will be removed in future releases, so I am wondering we have same case for SAPOSCOL and this might not be accreted value.
Also, I'd like to know for those who are using the Solution Manager for system monitoring, how you are monitoring the disk performance for your systems.
Thanks in advance,