Hi Ratnam,  The best practice for this type of expansion is to expand with the same size journal volume as it stripes across these volumes. In doing so, you can simply add "X"x100Gb volumes to it to grow the protection window to your desired size. So if you just want to extend the protection window a little bit, you can add a single 100Gb device. If you want to grow it much larger you can add more 100Gb volumes.  Let me know if that helps.  Thanks!
We have a distributed CG with multiple datasets. We already assigned 10X100 GB journals for this CG. I want to extend the protective windows. Is it allowed to give 5x100 GB or 10x 50GB instead of 10x100 GB? Should they have to be same as previous, that is 10 x100 GB to balance with the journal earlier?
Journal LUN for Distributed Consistency Group