DMP DSM for VCS SQL, Round Robin vs. Dynamic Least Queue Depth
What is the recommended setting for the Load Balance Policy for a SQL environment? Or, where can I find more information about the available settings? Thanks!
Explanation of DMP setting
Explanation of DMP setting should be the same, regardless of product, so here is the description from SFW 6.0 from SFW admin guide:
Dynamic Least Queue DepthSelects the path with the least number of I/O requests in its queue for thenext data transfer.For example, if you have two active paths, path A with one I/O request andpath B with none, DMP DSMs would select the path with the least numberof I/O requests in its queue, path B, for the next data transfer.
Round Robin with SubsetUses a subset of paths, each in turn, in round-robin fashion. The userspecifies the paths for data transfer that make up the subset. The remainingpaths are in standby mode.For example, if you have three active paths, path A, path B, and path C andyou specify the subset to contain path A and path B, then DMP DSMs woulduse path A for one data transfer and then use path B for the next. Path Cis in standby mode and is used if path A or path B fails.