I'm having a classic developer-system admin battle where I am stating that there is an IO problem on the disk of the shared sql server while the system admin tells me that the capacity hasn't been reached at all.
1 thing I was able to point out is that the avg disk queue length on the SQL server is very high. The avg queue length has an average of 5 and regularly spikes to 10 to 15. It never reaches below 2.5
The system admin tells me that's not a problem because the disk is a stripe of 6 disks and the queue length is by definition bad if it is higher then the double amount of the spindles. So his formula is 6*2=12 which is lower then the average 5.
Is his reasoning correct ? Can we just look at an azure disk as a spindle? The constant avg queue length of min 5 is not an indication?
EDIT: As it turns out, the disks were a huge bottleneck. The application runs smoothly again after moving the databases to a seperate database server.