This might not be exactly what you are looking for, but one way to potentially decrease that is to utilize only 4 paths per LUN by essentially allocating a host to a brick and round-robining the hosts between the bricks in that fashion. Its kind of a pain from a management perspective since the customer has to be mindful of that type of host/brick balancing, but this is supported and a way I have approached it with some of my customers due to the pathing limits you mention:  [IMAGE]
Hello,  VMware vSphere ESXi 5.5 and 6.0 have a limit of 256 LUNs per host: [URL] [URL] For the traditional (if I can call them that) storage arrays like VNX where there are two Storage Controllers and VMware Best Practice to have two HBAs connected to the two Fabrics the host will have four paths to a LUN: 2 Controllers x 2 HBAs = 4 paths When we use the same logic with EMC XtremIO clusters (two or more X-Bricks (max is currently 8), we should also consider another limit, the 'Number of total paths on a server' which is 1024. If you have a cluster of two X-Bricks, you have four controllers, multiply by two HBAs and you have eight paths to a LUN.  Therefore the max number of LUNs will be 1024 / 8 = 128. If you go to the extreme and configure your XtremIO with eight X-Brick, you have 16 controllers. Again, two HBAs per host and the max number of LUNs you can attach to an ESXi host will be 32... I understand, different OS'es may have different limits than in VMware environment and this logic will not be available.  We currently have XtremIO array with two X-Bricks (four controllers) that is used for Oracle T&D environment with multiple RDM mapped LUNs and have hit the limit of 1024 paths (1024 / 4 controllers / 2 HBAs = 128 LUNs).   How would you resolve this issues?   We can disable (manually or through the script) certain paths on the VMware ESXi host. And what logic we should apply to the selection criteria? Can we do something clever in EMC PowerPath/VE to limit the number of path it will use etc?...  Thank you.  Mark Strong www.vStrong.info
Multi X-Brick XtremIO clusters and VMware vSphere LUN/path limits