A vSphere administrator has created a Virtual SAN Cluster with Automatic Mode Disk Groups. The
cluster includes three ESXi hosts contributing one SSD and six SAS disks each. The administrator
has four new ESXi hosts that boot from a fiber channel array and have no local disks attached.
These four new hosts need additional shared storage but there is insufficient space on the fiber
channel array. The hardware budget is limited.
What can the administrator do to provide the needed storage for the lowest cost?
A.
Add the four new hosts to the Virtual SAN Cluster and use the existing storage in the cluster.
B.
Add an SAS RAID controller to each of the new hosts. Attach one SSD and six SAS disks to
each RAID controller and then add the four hosts to the Virtual SAN cluster.
C.
Add the four new hosts to the Virtual SAN Cluster and contribute the fiber channel disks to the
Virtual SAN.
D.
Add the four new hosts to the Virtual SAN Cluster and change to Manual Mode Disk Groups.
Explanation:
Even tough it is the most Expensive option. It is the only valid option! B.
Every ESX(i)Host in the Virtual SAN Cluster Must have an SSD!
Indeed it is the cheapest which will work 😉
See: which-statement-is-true-about-the-hardware-configuration-for-esxi-hosts-participating-in-a-virtual-san/
I’ll Take back my remark…
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2058424
Virtual SAN cluster nodes with no local storage
Not every host in the cluster needs storage. An ESXi host which is a Virtual SAN cluster node can boot from SAN, SD/USB, or local disk. Virtual machines can then run in memory, reading virtual machine files from the local disks of other cluster nodes.
For example, consider this sample environment:
A 4-node Virtual SAN cluster named Testgroup running 32 virtual machines. The Virtual SAN cluster nodes in Testgroup are:
ESX1 – Has 1 SSD and 1 HDD
ESX2 – Has 1 SSD and 1 HDD
ESX3 – Has 1 SSD and 1 HDD
ESX4 – Has no local storage and is booting from SAN
A Virtual SAN datastore has been created from the available local storage
The 3 SSDs and 3 HDDs in hosts ESX1, ESX2, and ESX3 are used to create a 500 GB Virtual SAN datastore named TestDS.
Note: SSDs do not contribute to the capacity of the Virtual SAN Datastore. SSDs are used only for read cache and write buffering.
Virtual machines stored on datastore TestDS are available to all Virtual SAN cluster member hosts.
Host ESX4 is running virtual machines stored on the TestDS datastore. The pieces of those virtual machines are physically located on storage which is locally attached to another cluster node. The virtual machine runs in the memory of host ESX4, but the read and write data is sent across the Virtual SAN network to the local storage of the other nodes.
A. is CORRECT!
A