Date: Thu, 10 Feb 2000 12:29:31 +0100 (CET) From: Micke Josefsson <mj@isy.liu.se> To: Ernst de Haan <ernst@znerd.demon.nl> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Boot record repair program? Message-ID: <XFMail.000210122931.mj@isy.liu.se> In-Reply-To: <38A28D6F.DE8BADDF@znerd.demon.nl>
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On 10-Feb-00 Ernst de Haan wrote: > It was in `compatible' mode, cuz Winblows didn't start up if me 2nd disk > was in `dangerously dedicated mode'. > > Any help would be greatly appreciated. I'm going to install a new harddisk > now and install FreeBSD on that one and then try to copy all data from the > old disk to the new. Problem is, I don't know where the partitions start >:( > > I used to have my partitions like this (for what I recall): > > 1st FreeBSD (about 3 GB) > 2nd Linux (about 3 GB?) > 3rd Linux swap (about 120 MB) > > But this is what FIPS gives me under DOS (i compressed the table): > > -------------------- > Which Drive (1=0x80/2=0x81/_)? 2 > > Partition table: > > |boot| Start | | End | Start |Number of| >#|able|Hd Cyl Sec|System|Hd Cyl Sec| Sector |Sectors | MB > -+----+----------+------+------------+--------+---------+---- > 1|yes | 1 768 63| FFh|254 1917 63|16711935| 16753663|8180 > 2| no | 0 894 63| FFh|254 1807 63|16753663| 16747519|8177 > 3| no | 0 768 63| FFh| 0 1792 63|16711935| 16711935|8160 > 4| no | 0 768 63| FFh| 0 1792 63|16711935| 16711935|8160 > > Checking root sector ... > Error: Invalid root sector signature: FF AA > -------------------- > > > This is weird as I dont recall havig _4_ partitions (but it could be I > created different partitions for / and /usr (?) ) and the size of the > partitions are way out of bounds for my Quantum Fireball 6.4A (6.4 GB) > > A partition table always have 4 entries, even if they are not used. (This is why the 1st partition in an extended partition is number 5). (A dangerously dedicated disk has no partition table at all. The sector used by the partition table is used by FreeBSD instead.) If this is the only partition info you have, you must have messed up your disk somehow. It states there is one (1) partition which starts at cylinder 768 and goes on till cylinder 1917. And possibly one partition inside this one (does not make sense for now). If this is the disk which contained the above FreeBSD/Linux/LinuxSwap then there should have been more info in this table or in the MasterBootRecord. You should have some info where cylindernumber is 0, this is where the 1st partition would start. The layout you claim should have been something like this: FreeBSD 1 0 63 | 254 xx 63 | Linux 0 xx+1 63 | 254 yy 63 | where xx is cylinder boundary and yy is ending cylinder (which may NOT need to be the actually max available cylinders, DOS/FAT-partitions may not be able to allocate all). I'm here assuming that 1) you have set up linux and FreeBSD in primary partitions and 2) the linux swap is contained within the linux partition (dunno if this is the way linux actually does it). If the linux partition is inside an extended partition then the 2nd entry above would have been of type EXTENDED and been pointing to yet another partition table. This latter table would also have had 4 entries, the 1st specifying the size of your linux partition, the 2nd pointing to possibly another extended partition. Entries 3 and 4 would have been empty. FreeBSD does not install in an extended partition, linux does. The usage of the word 'partition' above is in the DOS/FAT-language, a FreeBSD buff would have called them slices (slicii?) instead. If you don't touch anything and can boot off a boot floppy a friend of mine has a little hack to identify zombie partition tables laying around. With this info you should be able to make copies of possible partition table candidates and by time consuming (I know!) and careful bitfiddling make new partition tables. More (all!) info about your drive would also be neccassary to continue. What does BIOS see it as (C/H/S)? Have you repartitioned the drive before or are the partition tables inserted only once and on a fresh drive? Restoring partition tables is quite fun once you get the hang of it. It's a bit like archaeology or decryption, if that's your cup of tea! I'd like to hear of any success (and good luck!) /Micke PS. Perhaps you find it easier to start from a clean slate instead of going through all this trouble... PS2. The discussion above has got nothing at all to do with the partitions FreeBSD sets up inside a slice. ---------------------------------- Michael Josefsson, MSEE mj@isy.liu.se This message was sent by XFMail running on FreeBSD 3.1 ---------------------------------- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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