Re: emergency: can't boot! please help
On Sat, 23 Aug 2003 20:09, OZ wrote: Hi, I've got a massive problem and I need urgent help, please. Trying to set up a dual boot, and I've rendered my primary master (which has windows xp) un-bootable. On this page: http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/disks.html#NT-BOOTLOAD ER For the same disk situation this seems fairly clear; but for the different disk situuation I find it quite confusing. Nor do I suggest that I know how it should be done!!! in section 9.10... it says: - If FreeBSD is installed on the same disk as the NT boot partition simply copy /boot/boot1 to C:\BOOTSECT.BSD However, if FreeBSD is installed on a different disk /boot/boot1 will not work, /boot/boot0 is needed. Warning: DO NOT SIMPLY COPY /boot/boot0 INSTEAD OF /boot/boot1, YOU WILL OVERWRITE YOUR PARTITION TABLE AND RENDER YOUR COMPUTER UN-BOOTABLE! /boot/boot0 needs to be installed using sysinstall by selecting the FreeBSD boot manager on the screen which asks if you wish to use a boot manager. This is because /boot/boot0 has the partition table area filled with NULL characters but sysinstall copies the partition table before copying /boot/boot0 to the MBR. When the FreeBSD boot manager runs it records the last OS booted by setting the active flag on the partition table entry for that OS and then writes the whole 512-bytes of itself back to the MBR so if you just copy /boot/boot0 to C:\BOOTSECT.BSD then it writes an empty partition table, with the active flag set on one entry, to the MBR. - Well, I read that to mean that if I installed /boot/boot0 with sysinstall, THEN i should copy /boot/boot0 to C:\bootsect.bsd. I did this by following instructions I found elsewhere. In FreeBSD, I tried this: dd if=/dev/ad1 of=c:\bootbaby.sec bs=512 count=1 I see two problems here. Firstly 9.10 (ahead of where you quoted) says copy the first sector of your native root FreeBSD partition This is probably /dev/ad1s1 or /dev/ad1c not the first sector on the disk. Next c:\bootbaby.sec brobably ends up as a file in the FreeBSD filesystem c:bootbaby.sec (with the \ disappeared) in whatever directory you were in when you ran the command. It is probably easiest to copy this to a DOS format floppy and then again to C:\bootbaby.sec when back in XP. How you actually get this image into windows is not explained in the information. (I figured that by calling it bootbaby.sec, I'd rename it later to bootsect.bsd, which is what the NT loader dual boot item was set at from a previous failed attempt.) I may also have copied /boot/boot0 to c:\bootsect.bsd from off the CD. I don't remember at this point -- I've been panicking for about 3 hours now. Anyway... the point is this: My NT loader got screwed up, and now I can't even get into that disk (Windows XP is on the Primary Master, ad0, and FreeBSD is on the Primary Slave, ad1). Can you still get into FreeBSD and how? What happens an boot up? What appears on screen? It sounds as though you may have destroyed the MBR on the master disk when you went back to sysinstall. I've tried creating a boot disk: http://support.microsoft.com/default.aspx?scid=kb;en-us;305595 and even added some options, as suggested here: http://tweakhomepc.virtualave.net/dual/rescuebootdisk.html (and I used his exact boot.ini -- don't know what the original boot.ini was, but his seems about right)... but nothing's working. The error I get from that one is: Windows could not start because of a computer disk hardware configuration problem. Could not read from the selected boot disk. Check boot path and disk hardware. Please check the Windows documentation about hardware disk configuration and your hardware reference manuals for additional information. Now, this might not seem like a FreeBSD issue, since it's the Windows XP disk I can't get into, but it was the FreeBSD boot loader that got me into this mess. The FreeBSD warning was: Warning: DO NOT SIMPLY COPY /boot/boot0 INSTEAD OF /boot/boot1, YOU WILL OVERWRITE YOUR PARTITION TABLE AND RENDER YOUR COMPUTER UN-BOOTABLE! and although I was very careful about this and I was sure I WASN'T doing what they were warning me against... I think that's what has happened. I don't believe you managed to make the image available to the loader so this is unlikely to be the problem. How do I fix this? I've even tried attaching the drive to another computer (Win XP) as a Slave, to see if I could SEE the contents of the drive, but I can't. Please don't tell me this disk is gone. There's got to be a way to re-create the original partition table or re-write a new one that will see the disk's contents, etc.??? If you know what you did in installing XP then it might be possible for someone who knows more about how XP sets up disks to make a reasonable guess. That person is not me. This has
Re: emergency: can't boot! please help
On Sun, 24 Aug 2003 16:38, OZ wrote: --- Malcolm Kay [EMAIL PROTECTED] wrote: On Sat, 23 Aug 2003 20:09, OZ wrote: Hi, I've got a massive problem and I need urgent help, please. Trying to set up a dual boot, and I've rendered my primary master (which has windows xp) un-bootable. On this page: http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/disks.html#NT-BOOTLOAD ER For the same disk situation this seems fairly clear; but for the different disk situuation I find it quite confusing. Nor do I suggest that I know how it should be done!!! in section 9.10... it says: - If FreeBSD is installed on the same disk as the NT boot partition simply copy /boot/boot1 to C:\BOOTSECT.BSD However, if FreeBSD is installed on a different disk /boot/boot1 will not work, /boot/boot0 is needed. Warning: DO NOT SIMPLY COPY /boot/boot0 INSTEAD OF /boot/boot1, YOU WILL OVERWRITE YOUR PARTITION TABLE AND RENDER YOUR COMPUTER UN-BOOTABLE! /boot/boot0 needs to be installed using sysinstall by selecting the FreeBSD boot manager on the screen which asks if you wish to use a boot manager. This is because /boot/boot0 has the partition table area filled with NULL characters but sysinstall copies the partition table before copying /boot/boot0 to the MBR. When the FreeBSD boot manager runs it records the last OS booted by setting the active flag on the partition table entry for that OS and then writes the whole 512-bytes of itself back to the MBR so if you just copy /boot/boot0 to C:\BOOTSECT.BSD then it writes an empty partition table, with the active flag set on one entry, to the MBR. - Well, I read that to mean that if I installed /boot/boot0 with sysinstall, THEN i should copy /boot/boot0 to C:\bootsect.bsd. I did this by following instructions I found elsewhere. In FreeBSD, I tried this: dd if=/dev/ad1 of=c:\bootbaby.sec bs=512 count=1 I see two problems here. Firstly 9.10 (ahead of where you quoted) says copy the first sector of your native root FreeBSD partition This is probably /dev/ad1s1 or /dev/ad1c not the first sector on the disk. Are you saying that I didn't actually copy what I thought I did WHERE I thought I did? I don't understand what you mean. I don't know what you think you copied but your command reads the MBR on the slave drive which is not the same as the native root FreeBSD partition. But whether this is what is actually required I findn somewhat confusing. As far as the destination is concerned then c: is not special in BSD so it does not select a disk, and the backslash '\' is simply an escape character, it says don't impliment any special meaning of the next character so c:\bootbaby.sec is seen as a simple file name 'c:bootbaby.sec' in the FreeBSD system. If you had somehow mounted the ntfs on directory /c: then you might be able to write the file to /c:/bootbaby.sec to get it where you want. But I doubt whetherb you have a mounted ntfs system, and in any case I believe the FreeBSD ntfs support is somewhat flakey and writing to it is dangerous or not allowed. Next c:\bootbaby.sec brobably ends up as a file in the FreeBSD filesystem c:bootbaby.sec (with the \ disappeared) in whatever directory you were in when you ran the command. Hmmm. I understand what you're suggesting, but somewhere on the Net, it had suggested that the if=/of= thing (part of the dd command) would copy to the c: drive with the line that way. I honestly just don't know enough about how the commands work. I'm very new to FreeBSD. Is there any way to check? I don't even know how to navigate around FreeBSD -- I've only had it a week. It is probably easiest to copy this to a DOS format floppy and then again to C:\bootbaby.sec when back in XP. How you actually get this image into windows is not explained in the information. Do you know how to do this? Take a ms formatted floppy, put it in the drive and as root: # mount_msdos /dev/fd0 /mnt now you can write it with: # dd if=/dev/ad1c of=/mnt/bootbaby.sec bs=512 count=1 yoou should then unmount with # umount /mnt (I figured that by calling it bootbaby.sec, I'd rename it later to bootsect.bsd, which is what the NT loader dual boot item was set at from a previous failed attempt.) I may also have copied /boot/boot0 to c:\bootsect.bsd from off the CD. I don't remember at this point -- I've been panicking for about 3 hours now. Anyway... the point is this: My NT loader got screwed up, and now I can't even get into that disk (Windows XP is on the Primary Master, ad0, and FreeBSD is on the Primary Slave, ad1). Can you still get into FreeBSD and how? What
Re: emergency: can't boot! please help
OZ [EMAIL PROTECTED] writes: Well, I read that to mean that if I installed /boot/boot0 with sysinstall, THEN i should copy /boot/boot0 to C:\bootsect.bsd. Incorrect. That's what you were supposed to do: /boot/boot0 needs to be installed using sysinstall by selecting the FreeBSD boot manager on the screen which asks if you wish to use a boot manager. This means that you should not deal with /boot/boot0 file manually. This is because /boot/boot0 has the partition table area filled with NULL characters but sysinstall copies the partition table before copying /boot/boot0 to the MBR. dd if=/dev/ad1 of=c:\bootbaby.sec bs=512 count=1 This was not supposed to work as is. dd has no idea about your c: disk. So what exactly did you do? Please don't tell me this disk is gone. There's got to be a way to re-create the original partition table or re-write a new one that will see the disk's contents, etc.??? You may try Norton Disk Utils on that disk. It may find and restore another copy of you MBR. -- Alexander Pohoyda [EMAIL PROTECTED] ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: emergency: can't boot! please help
Hi, Thanks to Luke's suggestion, I'm currently attempting to load Linux over FBSD to then attempt to mount the NTFS drive, which may allow me to see the contents of that drive, to either copy them elsewhere to salvage the data, or to determine whether restoring it is possible. If you (or anyone on the list) have additional suggestions or ideas in light of this new scenario, please let me know urgently. Thanks!!! Do you have a spare disk with at least the same size than your problem disk? Then do a byte-by-byte backup first, to prevent even more damage during the following experiments. At least backup the MBR with dd if=/dev/hda of=backup.mbr count=1 bs=512 if you use some Linux bootdisk or dd if=/dev/ad1 of=backup.mbr count=1 bs=512 if you use FreeBSD First you must know, how your partition table looks like at the moment. A good tool to check this, is Linux fdisk from some bootable floppy (tomsrtbt) or CD (Knoppix), but any other free DOS tool is as good. If you don't write changed data back to disk, there is no danger to do any damage. - If there is a valid partition table still on disk, you're lucky. If I understand you correct, then you had a working Win XP before? Then I would first try to boot from the XP CD and start the recovery console from there. On the command line appearing there, you can enter fixmbr and fixboot. I don't know exactly how this will deal with corrupt partition tables, however. - If there is no partition table left on disk, things are more difficult. Do you know how (which tool, which size) you partititioned your disk in the first place? If yes, then you always have the chance to exactly reproduce your disk layout and regain your data by doing the same steps again. Ciao Siegbert ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
