Each host server supports up to 256 LUNs. However, on some hosts, it might be possible to exceed the guideline of 256 LUNs per host by changing host hardware or software settings.
When you configure vHBAs on individual host servers, use the following formula to verify that your deployment is in compliance with the general guideline of less than or equal to 256 LUNs per host:
(Number of vHBAs) * (Number of Targets per vHBA) * (Number of LUNs per target) <= 256
where:
Maximum number of vHBAs for a host is 16
Maximum number of targets for an vHBA is 64
Maximum number of LUNs per targets for a target is 256
Some examples of the formula and individual limits:
(2 vHBAs) * (64 targets) * (2 LUNs) = 256, which complies with the rule of 256 total LUNs per host, and the maximum of 64 targets per vHBA
(4 vHBAs) * (16 targets) * (4 LUNs) = 256, which complies with the rule of 256 total LUNs per host
(16 vHBAs) * (4 targets) * (4 LUNs) = 256, which complies with the rule of 256 total LUNs per host, and the maximum of 16 vHBAs per host
(4 vHBAs) * (4 targets) * (2 LUNs) = 32, which complies with the rule of 256 total LUNs per host. This example shows that less than 256 LUNs per host are supported.
(1 vHBA) * (1 target) * (256 LUNs) = 256, which complies with the rule of 256 total LUNs per host, and the maximum of 256 LUNs per target