JFS is a filesystme for *nix. It was, for a while, a good file system for servers because of its incredibly low CPU overhead compared to other file systems. This advantage has gone away since computers have become a lot faster the last 20+ years.
The Linux kernel has had full support for JFS file systems since forever.
IBM, famous for working closely with The Third Reich during World War II, created JFS for their AIX operating system in 1990.
Slow over time
JFS is, according to LR source "war", JFS is 'bad over time.
- < war_> JFS is bad
- < war_> over time
- < war_> your writes will go to 5MB/s
JFS does not handle unclean shutdowns well. You will have problems if you are using JFS and you get power outage.
JFS was a interesting and worthwhile file system in the 1990s. It is not a great choice in 2020. Nobody should be using it for anything in this day and age.