6.0

5 Enter 1 to enable or enter 0 to disable the memory compression cache.
6 Click OK.
Set the Maximum Size of the Memory Compression Cache
You can set the maximum size of the memory compression cache for the host's virtual machines.
You set the size of the compression cache as a percentage of the memory size of the virtual machine. For
example, if you enter 20 and a virtual machine's memory size is 1000 MB, ESXi can use up to 200MB of host
memory to store the compressed pages of the virtual machine.
If you do not set the size of the compression cache, ESXi uses the default value of 10 percent.
Prerequisites
Launch the vSphere Client and log in to a vCenter Server system.
Procedure
1 In the vSphere Client, select the host in the inventory.
2 Click the Configuration tab.
3 Under Software, select Advanced Settings.
4 In the left pane, select Mem and locate Mem.MemZipMaxPct.
The value of this attribute determines the maximum size of the compression cache for the virtual
machine.
5 Enter the maximum size for the compression cache.
The value is a percentage of the size of the virtual machine and must be between 5 and 100 percent.
6 Click OK.
Managing Storage I/O Resources
vSphere Storage I/O Control allows cluster-wide storage I/O prioritization, which allows better workload
consolidation and helps reduce extra costs associated with over provisioning.
Storage I/O Control extends the constructs of shares and limits to handle storage I/O resources. You can
control the amount of storage I/O that is allocated to virtual machines during periods of I/O congestion,
which ensures that more important virtual machines get preference over less important virtual machines for
I/O resource allocation.
When you enable Storage I/O Control on a datastore, ESXi begins to monitor the device latency that hosts
observe when communicating with that datastore. When device latency exceeds a threshold, the datastore is
considered to be congested and each virtual machine that accesses that datastore is allocated I/O resources
in proportion to their shares. You set shares per virtual machine. You can adjust the number for each based
on need.
Configuring Storage I/O Control is a two-step process:
1 Enable Storage I/O Control for the datastore.
2 Set the number of storage I/O shares and upper limit of I/O operations per second (IOPS) allowed for
each virtual machine.
By default, all virtual machine shares are set to Normal (1000) with unlimited IOPS.
NOTE Storage I/O Control is enabled by default on Storage DRS-enabled datastore clusters.
Chapter 25 Resource Management for Single Hosts
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