My vSAN Notes – Part 1

Integrated File Services
In vSAN 7, integrated file services make it easier to provision and share files. Users can now provision a file share from their vSAN cluster,
which can be accessed via NFS 4.1 and NFS 3 and SMB. A simple workflow reduces the amount of time it takes to stand up a file share

Storage Policy-Based Management (SPBM) abstracts storage services delivered by Virtual Volumes, vSAN, I/O filters, or other storage entities.
Multiple partners and vendors can provide Virtual Volumes, vSAN, or I/O filters support. Rather than integrating with each individual vendor or
type of storage and data service, SPBM provides a universal framework for many types of storage entities.

SPBM offers the following mechanisms:

• Advertisement of storage capabilities and data services that storage arrays and other entities, such as I/O filters, offer.

• Bi-directional communications between ESXi and vCenter Server on one side, and storage arrays and entities on the other.

• Virtual machine provisioning based on VM storage policies.

For RAID-5, a minimum of 4 hosts are required; for RAID-6, a minimum of 6 hosts are required. The objects are then deployed across the storage on each of the hosts, along with a parity calculation. The configuration uses distributed parity, so there is no dedicated parity disk. When a failure occurs in the cluster, and it impacts the objects that were deployed using RAID-5 or RAID-6, the data is still available and can be calculated using the remaining data and parity if necessary

A new policy setting has been introduced to accommodate the new RAID-5/RAID-6 configurations.

This new policy setting is called Failure Tolerance Method. This policy setting takes two values: performance and capacity. When it is left at the default
value of performance, objects continue to be deployed with a RAID-1/mirror configuration for the best performance. When the setting is changed to capacity,
objects are now deployed with either a RAID-5 or RAID-6 configuration.

The RAID-5 or RAID-6 configuration is determined by the number of failures to tolerate setting. If this is set to 1, the configuration is RAID-5.If this is set to 2, then the configuration is a RAID-6.

RAID 5 or RAID 6 erasure coding is available only on all-flash disk groups.
On-disk format version 3.0 or later is required to support RAID 5 or RAID 6.
You must have a valid license to enable RAID 5/6 on a cluster.
You can achieve additional space savings by enabling deduplication and compression on the vSAN cluster.

Leave a Reply

Your email address will not be published. Required fields are marked *