Shrinking large filesystem spanned across multiple luns
Hello, we have a mirrored/raid1 volume of 1TB spanned across two arrays (80 luns from each array) and its usage is now 400G (at some point usage was 850G). We need to shrink the filesystem to 500G so that we can utilize the space for new filesystem. I understand vxresize helps in this case and it will attempt to remove most recently added LUNs similar to stack LIFO mode. I am under impression that if the data extents are on the recently added LUN, that will be evacuated to free blocks on the old LUN and it will take considerable amount of time to complete the resize operation. I guess defragmenation prior the resize helps. I would like to know/estimate the resize operation time and wondering if there is any way to identify howmuch data is stored on a particular LUNs.
Thanks in Advance.