Hi all, Thought it would be a good time to bring up a discussion on the type of statistics that dm-multipath would find useful, e.g. for a load balancing path selection algorithm or for users. This is a list of statistics provided by an IBM multipathing product. (The discussion of how to gather these type of statistics would also require another discussion). Any thoughts/suggestions? Per Path Information: - Number of times the path was selected for I/O - Number of I/O errors on this path Per Adapter Information : - The number of times this adapter was selected for I/O - The number of errors on all paths attached to this adapter - The number of paths attached to this adapter - The number of functional paths attached to this adapter (i.e. Exclude failed or offline paths) Path Performance Information (more specific breakdown): Total Read I/O: Total number of completed read requests Total Read Sector: Total number of sectors that have been read Total Write I/O: Total number of completed write requests Total Write Sector: Total number of sectors that have been written Active Read I/O: Total number of read requests in process Active Read Sector: Total number of sectors to read in process Active Write I/O: Total number of write requests in process Active Write Sector: Total number of sectors to write in process Maximum I/O: The maximum number of active I/O requests Maximum Sector: The maximum number of active sectors to read or write Transfer Size: <= X , (X = {512, 4K, 16K, 64K}) The number of I/O requests received whose transfer size is X bytes or less > 64K The number of I/O requests received whose transfer size is greater than 64KB Adapter Performance Information: ** identical to Path performance information except no "Transfer Size'" info Thanks! Lan