I'm building high capacity storage for video. It is currently at 20TB mark and keeps growing. Currently, I have 12-bay enclosure filled with 2TB drives and configured in RAID-6. I'm considering to buy another 12-bay enclosure and fill it with 2TB drives as well and I'm considering the following 2 options:
- Either expand my RAID-6 array on 12 additional drives or
- Create another RAID-6 array from 12 new drives and then use LVM to expand the original volume.
In first case I will be facing ~4-6 weeks of rebuild time before I can use extra capacity. Also, if I need to add another shelf to this array later and use same approach the rebuild time will likely be even longer.
In the second case I'm loosing some capacity and potentially performance but it seems easier to handle and availability times are more predictable.
I also plan to grow this array to 7-10 shelves in total within next 2-3 years and the entire array will comprise one huge volume formated with XFS. So, could anyone speak from their experience and elaborate on pros and cons of each approach and potential problems I will be facing as time goes by.