During March I did two sessions for Microsoft and the topics where CloudOS and related technologies such as System Center 2012 R2, Azure Pack, Storage, VDI, Hyper-V and BYOD. I have recorded one of the sessions, but please be aware that narration is in Croatian language.
During these sessions some questions came up that I think are interesting so here they are:
Q: How and at what intervals Windows Server 2012 R2 calculates heat map for files that are saved on tiered (SSD + HDD) storage space?
A: After you create tiered storage space two scheduled tasks will be created and enabled and they are responsible for creating heat map for file access and storage optimization. These task by default run once every day but that can be modified.
Q: What are recommended values for VDI capacity planning?
A: Although it is very hard to give any specific data on this since every implementation is different, Microsoft has a whitepaper that can help with this, or at least give some general info on workloads that you can expect. This whitepaper describes 2500 seat VDI deployment: http://download.microsoft.com/download/2/4/B/24B5EC7D-1D03-49A2-B792-C7EDF24549EE/Windows_Server_2012_Capacity_Planning_for_VDI_White_Paper.pdf
Some conclusions from the this test deployment:
One core is needed per ten users to keep the core below 80% utilization
Each VM needed about 1GB RAM when running Windows 8 and Office 2013
I/O was about 10 IOPS per VM
400 Kbps bandwidth was needed per user
Q: What is recommended minimum of memory that should be reserved for Hyper-V host?
A: “You’ll need to reserve at least 300MB for the hypervisor and 512MB for the host OS running on the root partition. However, most best practices guidelines state that you should reserve 2GB for the parent partition. You shouldn’t use the host partition for anything other than Hyper-V (although you can run security and infrastructure software such as management agents, backup agents and firewalls). Therefore, that 2GB recommendation assumes you aren’t going to run any extra applications or server roles in the parent partition.” Source is http://technet.microsoft.com/en-us/magazine/hh750394.aspx.
Q: What is Smart Paging File?
A: “To provide a reliable restart experience for the virtual machines configured with less minimum memory than startup memory, Hyper-V uses Smart Paging. This memory management method uses disk resources as additional, temporary memory when more memory is required to restart a virtual machine.” More info can be found here http://technet.microsoft.com/en-us/library/hh831766.aspx.
Q: Are there any best practices in preparing Windows 8 base images for VDI scenario?
A: There are some recommended modifications:
Use 64 bit version of Windows 8
Disable BitLocker partition
Disable not needed service
Disable System Restore and Hibernate
Full detailed list and recommendations can be found in this document http://download.microsoft.com/download/6/0/1/601D7797-A063-4FA7-A2E5-74519B57C2B4/Windows_8_VDI_Image_Client_Tuning_Guide.pdf. Also, some automation script for creating optimized Windows 8 VDI base image can be found here http://blogs.technet.com/b/jeff_stokes/archive/2013/04/09/hot-off-the-presses-get-it-now-the-windows-8-vdi-optimization-script-courtesy-of-pfe.aspx.