kim wrote: > > Tony Abernethy wrote: > > James Hartley wrote: > >> On Fri, Feb 22, 2008 at 1:21 AM, kim <[EMAIL PROTECTED]> wrote: > >>> Just out of interest, what happens when you delete the 'c' > >> partition? I > >>> understood it deleted the drive spec but is this > >> irreversible? can you > >>> low level format the drive or repopulate the information > >> some other way, > >>> or with some other format software? > >> The definitive answer to your question is to try & see. Although I > >> have been curious about this at times, I haven't been so curious to > >> invest the time to experiment. > >> > >> As for conjecture, I would doubt that there is any physical harm in > >> deleting *all* partitions, but I doubt if there are any tools which > >> would reverse the result. I suspect one would end up having to > >> reinstall, but again, this is only a guess. > > > on an old installation (old computer, old OBSD) > > <snip> > > > partition to modify: [] c > > FS type: [unused] > > offset: [0] 3 > > The OpenBSD portion of the disk starts at sector 63, you > tried to add a > > partition at 3. You can use the 'b' command to change the > size of the > > OpenBSD portion. > > offset: [0] 66 > > size: [488397168] > >> w > > > > At this point, something is surely wrecked, HOWEVER > > I can log in again and disklabel now gives > > > The question being because I once did it, got stuck, gave up, got > another harddrive and continued playing. It was more because I never > knew what id done, and the manual doesnt seem to hold the information > how to get unstuck from this grey area. Many ways to mess something up. Few way to straighten things up. Details are in how when where etc OBSD actually put stuff on disk. (also matter of what's in cache and what's on disk) You should actually do better reading the source. There seem to be cases where you want to use say rwd0c instead of wd0c for "raw" access.
> > > Ah well. > > Time to wipe and reinstall something more like -current. > > Nothing quite like the feeling of wiping the disk you are > running on;) > > I don't know about most people but I quite enjoy the pleasure > of being > utterly confused by the state of the art partition system that comes > with obsd, its a bit like the installer it shows me how minuscule my > knowledge is yet even with a mundane understanding I can get > a somewhat > working system. DOS/Windows has the screwball partitioning system. The initial sector contains the initial boot sector which is used to find the bootable partition and read the next sector of the bootstrap. OpenBSD works on computer architectures other than just Wintel. Main thing is to realize that the word partition is really two very different words: DOS Partition (there are 4 primary partitions on disk) and OBSD Partition (there are 16 stored on the disk) There is not really any required connection between the two (assuming you're comfortable with a DOS partition being coexistent with a file on another DOS partition) changing the offset of 'c' from 66 to 77 works so at least disklabel is/was not dependent on having a valid 'c' partition to access the raw disk. > > Thanks for the info, and the experiment results, It might be > a good idea > to publish a webpage with the details of what you did, and how you > unstuck yourself from the situation. 1) I did NOT unstick myself --- whatever I clobbered does not YET matter. 2) kinda obvious the 'c' partition is how OpenBSD talks to the disk itself (instead of just to an OpenBSD (as opposed to DOS) partition It is possible that 'c' is required on some architectures and not on others. In which case, you're ahead to keep from messing up something which cannot be portable. Anything like this, helps if you have something (very) expendable. Also helps to have several ssh sessions into the victim machine. _______________________________________________ Openbsd-newbies mailing list [email protected] http://mailman.theapt.org/listinfo/openbsd-newbies
