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Table Of Contents
Advanced Memory Attributes
You can use the advanced memory attributes to customize memory resource usage.
Table 161. Advanced Memory Attributes
Attribute Description Default
Mem.ShareForceSalting Mem.ShareForceSalting 0: Inter-virtual machine Transparent Page
Sharing (TPS) behavior is still retained. The value of VMX option
sched.mem.pshare.salt is ignored even if present.
Mem.ShareForceSalting 1: By default the salt value is taken from
sched.mem.pshare.salt. If not specified, it falls back to old TPS (inter-
VM) behavior by considering salt values for the virtual machine as 0.
Mem.ShareForceSalting 2: By default the salt value is taken from
sched.mem.pshare.salt if present, or vc.uuid. If it does not exist,
then the page sharing algorithm generates random and unique value for
salting per virtual machine, which is not configurable by users.
2
Mem.SamplePeriod Specifies the periodic time interval, measured in seconds of the virtual
machine’s execution time, over which memory activity is monitored to
estimate working set sizes.
60
Mem.BalancePeriod Specifies the periodic time interval, in seconds, for automatic memory
reallocations. Significant changes in the amount of free memory also
trigger reallocations.
15
Mem.IdleTax Specifies the idle memory tax rate, as a percentage. This tax effectively
charges virtual machines more for idle memory than for memory they
are actively using. A tax rate of 0 percent defines an allocation policy
that ignores working sets and allocates memory strictly based on shares.
A high tax rate results in an allocation policy that allows idle memory to
be reallocated away from virtual machines that are unproductively
hoarding it.
75
Mem.ShareScanGHz Specifies the maximum amount of memory pages to scan (per second)
for page sharing opportunities for each GHz of available host CPU
resource. For example, defaults to 4 MB/sec per 1 GHz.
4
Mem.ShareScanTime Specifies the time, in minutes, within which an entire virtual machine is
scanned for page sharing opportunities. Defaults to 60 minutes.
60
Mem.CtlMaxPercent Limits the maximum amount of memory reclaimed from any virtual
machine using the memory balloon driver (vmmemctl), based on a
percentage of its configured memory size. Specify 0 to disable
reclamation for all virtual machines.
65
Mem.AllocGuestLargePage Enables backing of guest large pages with host large pages. Reduces
TLB misses and improves performance in server workloads that use
guest large pages. 0=disable.
1
Mem.AllocUsePSharePool
and
Mem.AllocUseGuestPool
Reduces memory fragmentation by improving the probability of backing
guest large pages with host large pages. If host memory is fragmented,
the availability of host large pages is reduced. 0 = disable.
15
Mem.MemZipEnable Enables memory compression for the host. 0 = disable. 1
vSphere Resource Management
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