That's something I did for small medium size data analysis (300Gb of csv). The reported size was around 800gb with indexes iirc and it fitted on a 512gb SSD.
It compresses the indexes pretty well but don't forget to turn off postgres' own copy on write mechanism
I am curious if you know anyone using Btrfs for this too. I like ZFS, but it Btrfs can do this it would be easier to use with some distros, etc. as it's supported in kernel.
The big problem for me from running DB on Btrfs is that when I delete large dirs or files (100GB+), it locks disk system, and Db basically stop responding on any queries.
I am very surprised that FS which is considered prod grade having this issue..
I haven't used XFS in almost two decades, does it have compression support in the same way? Also, does it do JBOD stuff? I know it's a bit of a different thing, but I really enjoy the pool many disks together part of Btrfs, although it has its limitations.
XFS doesn't have inline compression, nor does it have volume management functionality. It's a nice filesystem (and it's very fast) but it's just a filesystem.