Home > Storage > PowerMax and VMAX > Storage Admin > Implementing Dell SRDF SRA with VMware SRM > VMAX/PowerMax device masking requirements
In order for hosts to be able to see and use VMAX/PowerMax storage, hosts must be granted access to devices via software functionality referred to as Autoprovisioning Groups.
Autoprovisioning Groups is a VMAX/PowerMax feature that grants visibility to a certain device or set of devices from one or more host HBAs across certain front-end ports (a process mostly commonly known as masking). This is achieved by creating three logical constructs: a storage group (a group of VMAX/PowerMax devices), a port group (a group of VMAX/PowerMax front-end ports) and an initiator group (a grouping of host HBAs). These three groups are associated together via the creation of a masking view and therefore allows the initiators in the initiator group to see the devices in the storage group across the front-end ports in the port group.
In VMware environments, it is not always practical or useful to have recovery site target devices (TimeFinder replicas or SRDF remote devices) presented to the recovery ESXi hosts until the time of recovery/test recovery. This is an especially common requirement in enterprise environments where presenting large numbers of devices can threaten to exceed the ESXi device maximums. In more recent VMware releases this has become less of an issue, as ESXi 6.7 and higher supports 4096 logical paths per server and 1024 devices, however the feature can be desirable for other business reasons.
The SRDF SRA has the ability to add/remove devices as needed to the VMware environment--easing the burden on storage administrators. The following section discusses those masking requirements.
The SRDF SRA has the ability to automatically mask and unmask devices for recovery and test recovery operations. To achieve this, the SRDF SRA has two advanced options that, when enabled and properly configured, allow for the automatic masking of the device:
Note: If the R2 devices are not presented to the recovery site because RDF masking control will be used, and FilterNonVmwareDevices is set to ‘Yes’, it is essential that the masking file includes the R2 devices otherwise the device pairs will not show up in SRM.
These two options instruct the SRA to perform masking operations during either test recovery or recovery. When either one of these options are enabled, the SRA will query an XML configuration file called EmcSrdfSraDeviceMaskingControl.xml for the required information to properly Autoprovision the device.