The Grumpy Editor's guide to surviving the systemd debate

The Grumpy Editor's guide to surviving the systemd debate

No one is expected to port systemd to other platforms, because it's not expected at all!

It would be more appropriate to say that (a) the systemd developers don't see the point of portability patches to systemd because systemd relies heavily on kernel features that are currently only available on Linux in the first place, and (b) the systemd developers don't want their own code base cluttered up with portability #ifdefs. None of this prevents other people from actually trying to port systemd if they have nothing better to do with their time.

To port systemd to another Unix-like operating system kernel, somebody would have to remove all the Linux-specific bits from systemd and/or enhance the other kernel to provide compatible versions of those Linux-specific bits that one would consider worth supporting (considering that some of systemd's Linux-specific bits are really quite essential for its functionality). This would very likely involve a major effort, and – since most other Unix systems by now have their own take on an improved init – it is unclear whether such an effort would really be worthwhile. Having said that, it is fair to assume that if one is prepared to go to the trouble at all then having to maintain a separate OpenSSH-style “portable systemd” repository is probably the least of one's worries.

In this context it is worth mentioning that leading FreeBSD developers have recently gone on record to say that something like systemd would not be a bad idea at all for FreeBSD as far as they're concerned. Whether this means that FreeBSD will move towards evolving enough Linux compatibility to support a (partial?) systemd port, or whether the FreeBSD people will come up with something similar but unrelated by themselves is as yet unclear – but the fact that there is active interest does validate the principle of systemd's approach to basic plumbing (if not portability).