While trying to find up-to-date information on SCSI UNMAP and IBM Storwize products I came to find this blog post by Dusan Tekeljak which I found to be very interesting.
Especially the best practice part on RTC:
“To get best Real-Time Compression performance use at least 8 compressed volumes (LUNs) per V9000. Regardless what sales people tell you, it is not good thing from performance point of view to create one big volume (and not even talking from VMware point of view). There are 8 threads dedicated for RTC and one volume can be handled by 1 thread only.”
I am pretty sure everyone working with RTC on IBM Storwize/SVC products would like to have this written in bold letters on the product spec sheet so they can configure their MDISKs for best performance!