Availability classes
Aperçu
On the Val de Reuil Datacenter campus, the Cloud Avenue infrastructure is deployed in two rooms, each being completely independent of the other (energy, cooling, networks), which makes it possible to offer several classes of availability for a vDC.
Principes de base
- The location of a VM depend on the location of the storage policy used to create the vmdk of the VM.
- By default, a storage policy is not bound to a specific room. So location may be either room 1 or 2, because a storage policy is build from one or several datastores, which can be in either room 1 or 2.
- Only a localized storage policy can stick a VM in a specific room.
- By default the infrastructure carrying the T0 and T1 are in very high availability over 2 rooms. The loss of a room will not affect the vDC connectivity.
One Room
This is the default configuration, the vDC resources are provided by the two rooms, randomly, according to the capacity rules.
The Customer cannot choose on which room the VMs will be deployed, it is transparent for him.
This configuration is available for all performance classes.
Dual Room 1 vDC
The Customer chooses a vDC with 2 storage policies, one in each room.
This configuration allows him
to choose the location of the VMs.
The resilience of the service will be based on the application mechanisms (VM in cluster mode, web server farm configured in the Load Balancer, etc.)
The advantage of having a single vDC is for the capacity management, which is simplified compared to 2 vDCs (one in each room).
One Room rates apply.
This configuration is available for all performance classes.
Dual Room 2 vDC
The Customer orders 2 vDCs, one in each room.
This configuration allows him to choose the location of the VMs.
The resilience of the service will be based on the application mechanisms (VM cluster mode, server farm configured in the Load Balancer, etc.)
The Customer will have to manage the capacity of each vDC, as they are completely independent from the hardware point of view.
The networks can be shared between the 2 vDCs.
One Room rates apply.
This configuration is available for all performance classes.
HA Dual Room (aka HADR)
In this configuration, the computing and storage resources are spread over the two rooms, thus providing the very high availability of the infrastructure (computing + storage).
This is called HADR (High Availability Dual Room)
To activate this configuration, the Customer must order a single vDC in HA Dual Room mode (vDC rates in HA Dual Room apply).
The ordered storage will be automatically provisioned in Dual Room mode.
Storage is written to both rooms simultaneously (RAID 1) and is always available even if one room is lost.
The VMs located in the failed room will automatically restart on the ESXi in the second room, and will regain their storage.
This configuration is only available for Standard and High Performance classes.