Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!ucsfcgl!cca.ucsf.edu!root From: root@cca.ucsf.edu (Systems Staff) Newsgroups: comp.os.minix Subject: Re: switching file systems Summary: Simplifying assumptions Message-ID: <2461@ucsfcca.ucsf.edu> Date: 6 Oct 89 01:15:13 GMT References: <24987@louie.udel.EDU> <2453@ucsfcca.ucsf.edu> <1989Oct5.181148.8229@utzoo.uucp> Organization: Computer Center, UCSF Lines: 59 In article <1989Oct5.181148.8229@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: > In article <2453@ucsfcca.ucsf.edu> root@cca.ucsf.edu (Systems Staff) writes: > >Trading a one time minor task for a kludge > >that would complicate the logic of a critical element of the system > >and would add confusion, overhead, and bug-proneness for the long > >term isn't sensible. > > Filesystem switches have many uses other than filesystem conversions. Yes, but usually only on research or other special purpose systems (in this context we are only talking about filesystems for the same device population -- not like the differences due to mixed read/write and read-only media). A major goal of Minix is clarity and building in such unnecessary complication goes against that goal. Not to mention the problem of the user level incompatibilites which would be introduced (which your comments did not address) ... > And that "one time minor task" is one-time and minor only if it works > perfectly the first time. Well, I do make the simplifying assumption that you aren't going to reload your personal files until you have the new system running. That seems to be a reasonable assumption. So do the implicit assumptions that you are already familiar with your hardware and its reliability so you know whether you need multiple copies of your backups etc. and that you aren't so careless as not to label and write-protect your backup media. And then there are the possibilities of doing the conversion in situ or between separate areas (for those who have the space) on the hard disk avoiding the need to restore from backup media in the normal case. > Ask people about their 4.1BSD->4.2BSD conversions. I don't have to ask; I went through it. Likening reloading files on a personal system to dealing with the typically hundreds of megabytes belonging to hundreds of users on such systems and trying to make the changeover transparent to them is not appropriate for evaluating the former. Henry, thanks for your ever perspicuous comments. Thos Thos Sumner Internet: thos@cca.ucsf.edu (The I.G.) UUCP: ...ucbvax!ucsfcgl!cca.ucsf!thos BITNET: thos@ucsfcca U.S. Mail: Thos Sumner, Computer Center, Rm U-76, UCSF San Francisco, CA 94143-0704 USA I hear nothing in life is certain but death and taxes -- and they're working on death. #include