vSphere 4.1 to be announced July 13
Virtualization.info is reporting that the long discussed vSphere 4.1 will be announced on July 13.
While vSphere 4.1 will feature several performance improvements, several features have already leaked including memory compression and storage I/O control.
Storage I/O control will monitor the disk I/O performance of VMs at the VMFS level and make adjustments as needed in an attempt to minimize per-VM storage latency. This could prevent a scenario where other VM’s on the same volume are experiencing poor I/O performance due to another VM having a burst of I/O activity.
In the left illustration above we see a test VM (yellow) using up more disk I/O bandwith than a mission-critical server (red). In the right illustration, this is corrected using SIOC and share values inputed by the user.
Scott Drummonds has a good article about how this all works, and below is a movie which explains Storage I/O Control (SIOC) in action!
Tags: 
[...] Storage I/O Control (I had an earlier post on this here) [...]
[...] discussed in an earlier post and again here. This feature will allow the administrator to set a perference for I/O on a per VM [...]