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You administer two servers that run Windows Server 2012 R2. Both servers are part of a Hyper-V cluster. The servers are configured as shown in the following diagram:
All of the .vhdx files are stored on DISK1.
You observe that the physical input/output (I/O) performance degrades when .vhdx files are accessed.
You need to improve performance.
Which two actions should you perform? Each correct answer presents part of the solution.
A. Run the Windows PowerShell command Set-BCCache 10.
B. On each host server, enable write caching for DISK1.
C. Run the Windows PowerShell command Get-ClusterSharedVolumeBlockCacheSizeInMB = 0.
D. Run the Windows PowerShell command (Get- Cluster).SharedVolumeBlockCacheSizeInMB = 512.
E. Run the Windows PowerShell command Get-ClusterSharedVolume “Disk1” | Set-ClusterParameter CsvEnableBlockCache 1.
F. On each host server, disable write caching for DISK0.
Correct Answer: DE
Explanation/Reference:
http://windowsitpro.com/windows-server-2012/configuring-csv-cache
D: Configuring CSV Cache
Windows Server 2012 R2
1. Open an elevated Windows PowerShell prompt
2. Define the size of the size of the cache to be reserved (example of setting to 1 GB)
(Get-Cluster). BlockCacheSize = 1024
Note:
* There are two configuration settings that allow you to control CSV Cache.
E: CsvEnableBlockCache – This is a private property of the cluster Physical Disk resource. It allows you to enable CSV Cache on an individual disk. This gives you the flexibility to configure cache for read intensive VMs running on some disks, while allowing you to disable and prevent random I/O on other disks from purging the cache. For example parent VHD’s with high reads you would enable caching on Disk1, and high writes for differencing disks the CSV cache could be disabled on Disk2. The default setting is 0 for disabled, setting to a value of 1 enables CSV Block Cache on that disk. Note: In Windows Server 2012 R2 this property has been renamed to EnableBlockCache and is Enabled by default.
D: SharedVolumeBlockCacheSizeInMB – This is a cluster common property that allows you to define how much memory (in megabytes) you wish to reserve for the CSV Cache on each node in the cluster. If a value of 512 is defined, then 512 MB of system memory will be reserved on each node in the Failover Cluster. Configuring a value of 0 disables CSV Block Cache. Note: In Windows Server 2012 R2 this property has been renamed to BlockCacheSize.
* The main new features of the VHDX format are:
/ Support for virtual hard disk storage capacity of up to 64 TB.
/ Protection against data corruption during power failures by logging updates to the VHDX metadata structures.
/ Improved alignment of the virtual hard disk format to work well on large sector disks.
