> On Apr 7, 2015, at 9:40 AM, Chris Siebenmann <c...@cs.toronto.edu> wrote: > >> History lesson: until people could afford to purchase more than one >> disk and before Sun invented the diskless workstation (with shared >> /usr), everything was under /. > > As Richard knows but other people may not, this is ahistorical on > Unix. From almost the beginning[*] Unix had a split between the root > filesystem and the /usr filesystem, based (as far as I understand > it) on the physical disks involved at Bell Labs CSRG on their Unix > machine. This is part of why the split of commands between /bin and > /usr/bin existed for years. Sun's diskless machines did not invent a > split /usr, they just took advantage of existing practice and made it > read-only and shared.
Splitting some hairs... originally the OS was in / and user programs in /usr (hence the name) It was later that the thing we now call the "OS" moved to /usr. Now the "OS" is moving elsewhere, invading as it goes, as Volker described rather well. The key point is that trying to use filesystem(5) as written only works if everyone uses it, and they don't :-( with /opt being the perfect example of organizational dysfunction. The packaging system doesn't matter as it just sweeps the dust under the rug. IMHO the companies that solve this take the reductionist path: one file system. When done well, upgrades and installation are painless and my grandmother has no problem upgrading her phone without assistance. My approach to creating filesystems is based on policies to be applied, where those policies are fundamental to filesystems. Harkening back to the diskless workstation example or the more modern SmartOS model, there can be a readonly policy for the fixed OS bits that are replaced en masse. Other common policy knobs include: quota, reservation, backup, dedup, compression. Back to the problems at hand: 1. BE managing /opt as if it was its own, exclusive, waterfront resort. IMHO trying to assert an upgrade en masse policy to /opt is futile. Oracle's hack in Solaris 11.2 just kicks the can down the street. 2. Saving space for dumps. Don't waste time dumping to ZFS, setup a dump device on a raw partition somewhere. No need to mirror it or back it up. -- richard _______________________________________________ OmniOS-discuss mailing list OmniOS-discuss@lists.omniti.com http://lists.omniti.com/mailman/listinfo/omnios-discuss
