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A combination of XFS and ZFS. I work in high performance computing (academic). While I love the reliability of ZFS for data archival and peace of mind that results provably haven’t suffered bitrot, sometimes I just need a 10 TB temp file(s) with fast mostly-sequential R/W. Appropriate selection of file systems lets me have both.
As an aside, I’ve been watching bcachefs with some interest, as it seems to be getting faster with every kernel release, building on the data integrity guarantees of ZFS while pushing performance boundaries and being GPL compatible (i.e. in tree). Kent Overstreet et al. have done a fantastic job with this FS.