Updates to Dynamic Memory UI in SP1 RC – Part 2

Last week I discussed some of the changes that were made to the Hyper-V manager in response to feedback from beta users of the service pack 1 release.  Today I am going to talk about the changes that were made to the virtual machine settings user interface:


There are three changes that have been made here.  In reverse order of complexity (simplest change first):


  • “Memory priority” is now “Memory weight”

    This was changed for two reasons.  First, it is more consistent with other areas in Hyper-V where we have a similar concept and use the term weight (for instance: you can specify the relative weight of the processor resource).  Second, there was some user confusion where people expected virtual machines with a higher memory priority to be treated in particularly special ways.  The memory weight is only used when there is contention for memory resource – and virtual machines with higher weights are given greater consideration when distributing memory.

  • The memory buffer is now configured using a text box instead of a slider.

    A number of users complained that it was hard to tell at a glance what the exact memory buffer was for a given virtual machine.  Using a text box makes this obvious.

  • Memory buffer now uses different math.

    In the beta release the memory buffer specified what percentage of the total memory used by the virtual machine should be buffer (e.g. so a virtual machine that needed 900MB of memory with an 80% buffer would end up using 4.5GB of memory – making the buffer use 80% of the total 4.5GB of memory).  Most of our users did not think of it in this way – so now the buffer is the percentage above the used memory.  So a virtual machine that needs 900MB of memory and has an 80% buffer will get 1620MB of memory (900MB needed plus 80% more – or 720MB extra – for a total of 1620MB).  This also means that the acceptable range of input is changed too.  You can now have a buffer that goes from 5% to 2000%.