EMC Unity array was released in 2016 to replace VNX and VNXe family with another mid-range array solution. EMC Unity came with lots of new features and enhancements compare to older families but there was an absent feature that VNX offering. Host access method was changed and each LUN should have been present to each host separately.
More than 4 years from GA release, we were waiting for changing host access method because presenting LUN to each host was horrible in large scale environment with many hosts and LUNs.
Biggest Change In EMC Unity OE 220.127.116.11.5.394
Previous versions have “Consistency Group” with some limits to present a LUN or more than one LUN to group of hosts. EMC Unity OE 18.104.22.168.5.394 including new feature that the new feature is like VNX Storage Group. The new feature called “Host Group“.
You could assign or present multiple LUN to multiple hosts in OE version 5.0 and later but Host Group is the feature that we want.
In Dell EMC Unity OE version 5.1 users can logically group hosts and block resources within a host group. Host groups can be created and managed from the Host Groups tab and help to streamline host/resource access operations. A host group can be one of two types, General and ESX, which is persistent for the life of the group. A General type host group allows one or more non-ESXi hosts and LUNs to be grouped together. ESX host groups allow VMware ESXi hosts to be grouped with LUNs and/or VMFS datastores.
When a host is added to a host group, the host automatically is mapped to all resources assigned to the group. When adding a host to the group a merge option is also available, which maps all block resources assigned to the host to the host group and all hosts in it. If merge is not used, the resource attached to the host will be displayed within the host group, but access is restricted and remains unchanged. When a resource is added to the group, it is automatically mapped to all hosts within the group. Configuring host access using the resource creation wizard or on an existing resource remains unchanged.
You can find all other major changes and enhancements on EMC Unity OE Release Notes document.