Hi All,
Not new to virtualisation, however am pretty green to Hyper-V and liking the look of it so far.
Dynamic memory looks awesome, however I do see some "education" issues arising from the way memory is reported inside the guest. With VMware (where my background is) it doesn't matter how much memory is reclaimed, inside the guest this is always
reported as the amount you specify for the guest. This appears to be different with Hyper-V dynamic memory where;
a) Memory is hot added as required up to the configured maximum which is reflected in task manager, perfmon, etc.
b) if a guest startup memory is configured to more that what it needs, then when memory is reclaimed task manager, perfmon, etc inside the guest show you are using more memory than what you actually are.
The issue I see senario A producing is that VM owners will see their server has less memory than what they have ordered and won't understand that memory will be hot added as needed, and also that programs that check for available ram before actually
requesting it will throw errors (install of SCOM 2012 for instance). The only way I see getting around this while still using Dynamic Memory is to up the startup ram to be equal to the maximum ram, however this produces senario B where a guest appears to be
using a lot more ram than it is once the reclaimation process takes place.
Long story short, use of Dynamic Memory effectively breaks the historic method of measuring memory utilsation. Is there a way to mask the back end Dynamic Memory activity for the guest ? If not, then is there a way I can show VM owners to effectively
measure their memory utilisation in regard to consumed as a percentage of the maximum?
I really hope there is something I am missing here, as otherwise I see Dynamic Memory being a real hard sell to our business units.
www.iis-aid.com
