Ch3 Def Flashcards
Memory Ballooning
Memory is loaned to free up space. Loaned memory is placed into a Balloon and made available when needed by the VM.
Memory Compression
Memory pages are compressed and placed into a compression cache. When needed, a page is retrieved from the cache and uncompressed.
• Some performance impact
Swapping / Paging to Disk
If there is insufficient memory, the Hypervisor dumps data from Memory onto a page file.
• Slow Process, Performance Cost
• Use as Last Resort
Thick Provisioning
Virtual Disk size is specified and Pre-Allocated during Creation.
Thin Provisioning
The Virtual Disk starts small, and more chunks of memory are added as needed.
Administrators should Monitor…
• The amount of Free Space
• The amount of RAM used
• CPU Ready / CPU Utilization
CPU Utilization
A High CPU Utilization indicates the Host may be Overloaded.
CPU Ready
The amount of Time a VM must wait for pCPUs to become available.
• 5% or below = Best practice
VMs require a ___ for Communication.
Virtual NIC
Failover Clustering
Multiple physical Hosts with shared storage are configured to provide Redundancy. Agents are placed on Hosts and monitor other Hosts through Heartbeat Connections.
• Ensures HA
VM Cloning
Creates a replica of an existing VM. The original VM is the Parent, and the new VM is the clone.
Linked Clone
Shares virtual disks with the Parent.
Full Clone
Creates its own virtual disks.
• Faster Performance
• Takes longer to create
Snapshot
The state of a VM is captured and stored as it was. Captures can be taken at any time.
What is contained in a Snapshot?
• VM Disk State
• VM Memory
• VM Settings
