I am looking to get a little bit of guidance and some recommendations on what to do with my raid group. I have a TS-1679u-RP loaded out with 16 4tb drives in raid 6 with 1 hot spare. Slowly I am starting to have issues with the drives as they are getting older so I am replacing them with 8tb drives as they fail. Being a naive person back when I setup this big raid group thinking it was the best option not realizing that all 16 drive would need to be replaced to get more storage.
The NAS primarily stores video for PLEX and backups of all my VMs and desktops. Now that I have enough extra storage to pull everything off and rebuild the raid group I just want to see if there are recommendations as to how I should build my raid groups and storage pools. Currently I am at 23tb used for video, 5tb in backups and 2.3tb of other stuff. With this I am thinking that my video collection is where I would like most of the protection since it would be the biggest pain to replace but needs to be easily expandable as that is where the most growth is.
I am not sure if I should do multiple storage pools with different raid levels depending on the use or if I should keep one pool with multiple raid groups and what type off raid they should be. I have had thoughts of maybe 1 pool, 2 groups of 8 in raid 6, or 1 pool 2 groups of 5 and 1 of 6 in raid 6. It has been mentioned to me that 1 pool of 4 groups in raid 5 would be a bad idea as I would lose a bunch of capacity and if 1 group fails all is lost.
Any thoughts and recommendations are greatly appreciated.