In vSphere 5.0, VMware has released a new storage appliance called VSA. VSA is an acronym for “vSphere Storage Appliance”.
This appliance is aimed at our SMB (Small-Medium Business) customers who may not be in a position to purchase a SAN or NAS array for their virtual infrastructure, and therefore do not have shared storage. Without access to a SAN or NAS array, SMB customers are unable to implement many of vSphere’s core technologies, such as vSphere HA & vMotion. Customers who decide to deploy a VSA can now benefit from many additional vSphere features without having to purchase a SAN or NAS device to provide them with shared storage.
2. Introduction (1 of 3)
In vSphere 5.0, VMware will release a new storage appliance called
VSA.
VSA is an acronym for “vSphere Storage Appliance”.
This appliance is aimed at our SMB (Small-Medium Business)
customers who may not be in a position to purchase a SAN or NAS
array for their virtual infrastructure, and therefore do not have shared
storage.
Without access to a SAN or NAS array, SMB customers are unable to
implement many of vSphere‟s core technologies, such as vSphere HA &
vMotion.
Customers who decide to deploy a VSA can now benefit from many
additional vSphere features without having to purchase a SAN or NAS
device to provide them with shared storage.
3. Introduction (2 of 3)
VSA VSA VSA
vSphere vSphere vSphere VSA Manager
vSphere Client
NFS NFS NFS
Each ESXi server has a VSA deployed to it as a Virtual Machine.
The appliances use the available space on the local disk(s) of the ESXi
servers & present one replicated NFS volume per ESXi server. This
replication of storage makes the VSA very resilient to failures.
4. Introduction (3 of 3)
The NFS datastores exported from the VSA can now be used as
shared storage on all of the ESXi servers in the same datacenter.
The VSA creates shared storage out of local storage for use by a
specific set of hosts.
This means that vSphere HA & vMotion can now be made available
on low-end (SMB) configurations, without external SAN or NAS
servers.
There is a CAPEX saving achieved by SMB customers as there is no
longer a need to purchase a dedicated SAN or NAS devices to
achieve shared storage.
There is also an OPEX saving as the management of the VSA may be
done by the vSphere Administrator and there is no need for dedicated
SAN skills to manage the appliances.
The installation & configuration is also much simpler than that of a
physical storage array or other storage appliances.
5. Supported VSA Configurations
The vSphere Storage Appliance can be deployed in two configurations:
• 2 x ESXi 5.0 servers configuration
• Deploys 2 vSphere Storage Appliances, one per ESXi server & a
VSA Cluster Service on the vCenter server.
• 3 x ESXi 5.0 servers configuration
• Deploys 3 vSphere Storage Appliances, once per ESXi server.
Each of the servers must contain a new/vanilla install of ESXi 5.0.
During the configuration, the user selects a datacenter. The user is then
presented with a list of ESXi servers in that datacenter.
The installer will check the compatibility of each of these physical hosts
to make sure they are suitable for VSA deployment.
The user must then select which compatible ESXi servers should
participate in the VSA cluster, i.e. which servers will host VSA nodes.
VSA then „creates‟ the storage cluster by aggregating and virtualizing
each server‟s local storage to present a logical pool of shared storage.
6. vCenter Server
VSA Manager VSA Cluster Service
Manage
Volume 2 Volume 1
Volume 1 Volume 2
(Replica) (Replica)
VSA VSA
Datastore 1 Datastore 2
VSA cluster with 2 members
7. vCenter Server
VSA Manager
Manage
VSA
VSA VSA
Datastore 2
Datastore 1 Datastore 3
Volume 3
Volume 1
(Replica)
Volume 2
Volume 3
(Replica)
Volume 1
Volume 2
(Replica)
VSA cluster with 3 members
8. Simplified UI for VSA Cluster Configuration
Once the VSA Manager installation has completed and the VSA
manager plug-in is enabled in vCenter, select the datacenter in the
vCenter inventory and select the VSA Manager tab. The following is
displayed:
9. Simplified UI for VSA Cluster Configuration
Introduction Datacenter
Selection
1 2
ESXi host IP Address
Selection Assignment
3 4
10. Simplified UI for VSA Cluster Configuration
Select Disk Ready to
Format Install
5 6
11. VSA Manager
The VSA Manager helps an administrator perform the following tasks:
1. Deploy vSphere Storage Appliance instances onto ESXi hosts to create a
VSA cluster
2. Automatically mount the NFS volumes that the each vSphere Storage
Appliance exports as datastores to the ESXi hosts.
3. Monitor, maintain, and troubleshoot a VSA cluster
12. Resilience
Many storage arrays are a single point of failure (SPOF) in customer
environments.
VSA is very resilient to failures.
If a node fails in the VSA cluster, another node will seamlessly take over
the role of presenting its NFS datastore.
The NFS datastore that was being presented from the failed node will
then be presented from the node that holds it‟s replica (mirror copy).
The new node will use the same NFS server IP address that the failed
node was using for presentation, so that any VMs that reside on that
NFS datastore will not be affected by the failover.
13. vCenter Server
VSA Cluster
VSA Manager
Service
Manage
Volume 2 Volume 1
Volume 1 Volume 2
(Replica) (Replica)
VSA VSA
Datastore 1 Datastore 2
Failover in a VSA cluster with 2 hosts
14. Maintenance Mode
The are two types of Maintenance Mode:
• Whole VSA Cluster Maintenance Mode
• Single VSA Node Maintenance Mode
A user can put a particular VSA node into maintenance mode in order to
reconfigure the VSA in some way, e.g. rolling upgrade.
Since only one VSA is being taken offline, the storage volumes being
supplied by the storage cluster will remain online, therefore there is no
need to migrate any VMs utilizing that storage.
This does mean, however, that at least 2 volumes will be degraded with
the loss of one VSA. This should be addressed as quickly as possible as
a further failure in the VSA will lead to a storage outage scenario.
15. VSA Cluster Node/Member Replacement
If a VSA cluster member stops responding, its status changes to Offline
in the VSA Manager tab.
If an admin cannot bring the VSA Cluster member back online by
resetting it, another option available to the admin is to replace the VSA
cluster member.
16. VSA Cluster Recovery
In the event of a vCenter server loss with no backup, the VSA cluster
can be recovered with a vanilla install of vCenter.
The admin will have to re-install the VSA plugin in the new vCenter.
•When vSphere Client is launched
and the VSA tab is selected, it will
contain two options (the same
options visible during the initial
install). In this case the admin can
choose to Recover the VSA
cluster.
17. vSphere Storage Appliance: Summary
Installed, configure and managed via vCenter
Simple manageability
Abstraction From Underlying Hardware
Resilient to server failures
Delivers
High availability Highly available during disk (spindle) failure
Provides Storage framework for vMotion, HA and DRS
Pools server disk capacity to form shared storage
Creates Shared
Leverages vSphere Thin provisioning for space utilization
Storage
Enables storage scalability