Resource Pools

Question 1

What is the 2/3 to 1/3 ratio

Answer 1

Objects with high shares will have 2/3s of the entire resources and objects with normal shares will have half of that 1/3.

Question 2

Where do VMs in child resource pools go when the child resource pools are deleted?

Answer 2

To the parent resource pool

Question 3

What are the 4 caveats for adding VMs to resource pools?

Answer 3

■ If the virtual machine is powered on and the resource pool does not have adequate resources to guarantee its reservations, admission control will not allow the move to complete.

■ Virtual machine–configured reservations and limits will not change.

■ Virtual machine shares of high, medium, or low will be adjusted to reflect the total number of shares in the new resource pool.

■ Virtual machine shares configured with a custom value will retain the custom value. A warning will appear if a significant change in total share percentage would occur.

Question 4

What is the virtual flash read cache

Answer 4

An aggregation of virtual disks used for swapping

Question 5

What are the two main components of the flash read cache?

Answer 5

• vSphere Flash Read Cache software — provides a write-through (read) cache that can increase the performance of many workloads running in virtual machines, especially for read-intensive workloads or those with high percentages of data locality requirements. ■ vSphere Flash Read Cache infrastructure — resource manager and broker for Virtual Flash Resource consumption and the enforcer of admission control policies.

Question 6

What are the system requirements of the vSphere Flash Read Cache

Answer 6

• ESXi 5.5 and newer

■ vCenter Server 5.5 and newer

■ vSphere Web Client is required to manage and configure

■ VM hardware version 10 (ESXi 5.5 and later compatibility)

■ Each ESXi 5.5 or newer host must have a supported flash-based device listed in the HCL

■ Enterprise Plus licensing

Question 7

What are some flash read cache limitations?

Answer 7

• 1 Virtual flash volume per ESXi host
• SSDs per volume are 8 or less
• SSD flash based device size of 4TB or less
• Virtual flash size 32TB or less

Question 8

How does DRS behave with VMs configured with virtual flashes?

Answer 8

It places them but does not move them unless the host is put into maintenance mode or there is a major imbalance

Question 9

What is the file system of a vFlash volume

Answer 9

VFFS