We are looking at separating each of our buckets in different physical disks. I note (by observation) that couchbase create a folder for each buckets. In theory, it is possible to map each folders to a different mounted disks in RHEL. However I also would like to hear from anyone who had experience in such arrangement, or maybe it is just a stupid idea afterall 
There’s no reason what you suggest wouldn’t work, although it’s more common to use something like LVM to form a single logical volume from multiple disks - that allows all buckets to share the increased performance of the disk group.
Note if you do go down this route, you need to make sure that all disks are correctly mounted whenever you restart Couchbase, as it can get quite upset if Bucket data vanishes from underneath it!
Indeed it is definitely the right thing (gain increased performance from disk group) to do technically. Within the enterprise, separation of data (both logically and physically) seems to be highly value at times.
Thank you. I will be mindful of your word on mounting.