Factors such as array LUN size, Data ONTAP overhead, and checksum type impact the number of array LUNs that you need.
You should consider the following when determining the number of array LUNs that you need:
Ideally, creating one large array LUN from a given storage array RAID group is recommended.
The Hardware Universe contains information about device limits.
The amount of usable space in an array LUN is determined by the space that Data ONTAP requires, checksum type, and additional factors such as space required for optional Snapshot reserves.
When determining the assignment of array LUNs to Data ONTAP systems, you should consider what the storage will be used for and the number of requests that are likely to be generated by different applications.
Starting in Data ONTAP 8.2, the supported number of visible array LUNs on an FC initiator increased from previous releases as part of the shared FC initiator support introduced in Data ONTAP 8.2. (Prior to Data ONTAP 8.2, support is limited to one FC initiator connecting to just one storage array target port, and fewer visible array LUNs than in Data ONTAP 8.2.)
The FlexArray Virtualization Best Practice Guide documents the supported number of visible array LUNs on an FC initiator port for different Data ONTAP releases. The FlexArray Virtualization Installation Requirements and Reference Guide contains information about the requirements for shared FC initiator ports.