IOPS reservations in SIOC 6 , what’s the deal?

Storage I/O control has been available for a long time now since vSphere 4.1, if you don’t know what SIOC is you can read about it in many blogs out there, my personal favorite for anything storage is Cormac Hogan‘s blog, here is also a link to Cormac’s post about SIOC.

Some of you might have read about the new SIOC feature in vSphere 6 called IOPS reservations.

In case you didn’t let’s quickly review it, In version 5.5 VMware introduced a new scheduler call mClock, this I/O scheduler is more efficient but also it has the capability to set I/O reservations on VMDK’s. In vSphere 6 VMware added the ability to set those reservations on the VMDK level, not through the web client but by setting the “reservation” property on the VMDK, see this post by William Lam that has a nice PowerCLI script to do this for you.

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