Supporting More Partitions

“’15 partitions (at least for sd_mod devices) are too few,’ Jan
Engelhardt suggested along with a patch to try and make the
mounting of an unlimited number of partitions possible. H. Peter
Anvin proposed as an alternative, ‘now when we have 20-bit minors,
can’t we simply recycle some of the higher bits for additional
partitions, across the board? 63 partitions seem to have been
sufficient; at least I haven’t heard anyone complain about that for
15 years.’

“Alan Cox explained, ‘this was proposed ages ago. Al Viro vetoed
sparse minors and it has been stuck this way ever since. If you
have > 15 partitions use device mapper for it. I’d prefer it
fixed but it’s arguable that device mapper is the right way to punt
all our partitioning to userspace…'”

Complete
Story