From: Bela Lubkin <firstname.lastname@example.org> Subject: Re: Booting SCO 3.2v4.0 hard disk image in VMware or Bochs Date: 31 Jan 2006 14:01:54 -0500 Message-ID: <email@example.com> References: <Pine.CYG.4.64.0601310954250.1204@nighthawk> Robert Giles wrote: > Hi folks - I'm trying to boot a dd'd disk image of an IDE-based SCO system > inside VMware 5.5, Bochs IA-32 emulator, or an actual Athlon-based PC. > > This is the entire image of a 170MB hard drive to include partition table, > etc. as captured by "dd if=/dev/hda of=disk.img" from a Knoppix boot CD... > > In all three cases (VMware/Bochs/Athlon box), I get > "SCO UNIX System V/386 i80486" followed by a "boot:" prompt. > > "hd(40)unix" or simply pressing enter causes the kernel to load, but the > system immediately restarts after the the kernel load is complete (ie: > after .text, .data, .bss output to the console). > > If I type "dir" at the "boot:" prompt, I can see a filesystem on the disk > image, so I'd guess the image is valid - but I've heard that SCO's IDE > controller support back then was extremely limited. > > VMware presents the disk image to the guest OS as a SCSI disk hanging off > a Buslogic controller, but I'm not sure how to migrate a virtual SCO > system from IDE to SCSI when I can't boot the image in the first place :) > > (I have 3.2v4.0y N1/N2 disks, but it reboots immediately after the kernel > load and "Insert N2, press enter" part - same as the hard disk image). > > I can't mount the filesystem in Linux, either - I get a > "VFS: unable to find oldfs superblock on device" with the sysv module. > (this is with both loop devices and an actual IDE device /dev/hda4). > Possibly an HTFS filesystem, unsupported in Linux? > > It'd be great to get this disk image to boot, or even to be able to grab > the files out of it - any ideas out there?
I've booted OSR5, but have never tried 3.2v4.x, in VMware Workstation. I can't think of any difference that would definitely doom the attempt, but I can imagine there might be one... But from what you describe, there's a pretty big problem to start with. If the image is from an IDE drive, it isn't going to be happy suddenly booting up on a SCSI disk. Fortunately, VMware will also emulate IDE disks. So that should be your first move: reconfigure your VM to use IDE. If you didn't see that option, create a new VM and look again. Tell it you're installing "other/other" OS. When you get to the disk setup, you may need to click on "advanced" to get to the IDE-vs-SCSI options. As a diagnostic, you can boot with: Boot : defbootstr prompt The kernel will load, then (still in the boot program) you'll get a prompt before the kernel starts running. If you don't make it to the prompt, that tells us something. I think you _will_ get that far. At that point, type "v" (return) and you should get a memory map. Post that, trying to keep it accurate... HTFS first appeared in OSR5.0.0, so that isn't the problem with mounting under Linux. It probably doesn't have the right driver to _find_ the filesystem in its division within a partition. You can overcome that by using `dd` to chop out just the filesystem -- if you can figure out its start block. There are many ways to do this, none of them easily described in a few words...
Yet another route would be to install OSR5 (any version you can get to fly) on an IDE drive within a VM. Then add the 170MB image as a second IDE drive and use `mkdev hd` to attach it. Or, again you could use `dd` to slice out just the filesystem, then put it onto any OSR5 system (real or virtual) as a single large file, use `marry` to make it into a block device, and mount that. The basic problem you have to solve is finding the filesystem within the division within the partition. All of the proposed solutions break down to two basic routes to this goal: (1) chop it out manually, (2) use software -- 3.2v4.0 itself or OSR5 -- that has built-in knowledge of the SCO divisioning scheme. >Bela<
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