finding alternate superblocks in ffs

[Erik Udo]

What if you repartition & slice the disk exactly the way it was in 
sysinstall, and then Toggle Newfs off, and write changes. It worked
fine for me.


Christoph P. Kukulies wrote:
> Yesterday a major desaster happened: I stumbled across the power cable of my
> Dell Inspiron notebook. The notebook fell to the floor. FreeBSD was running
> at that time. Nothing seemed to got damaged, just a palm rest popped off.
> 
> Ah yes, the HD bay sprung off and in a moment of reflex I pushed it
> in again in the running system. After that I tried to mount the
> disk (which had not been mounted at that point of time). Anyway,
> trying to
> 
> # fsck_ffs /dev/ad2s1e
> ** /dev/ad2s1e
> Cannot find file system superblock
> 
> LOOK FOR ALTERNATE SUPERBLOCKS? [yn] y
> 
> 32 is not a file system superblock
> 89808 is not a file system superblock
> 179584 is not a file system superblock
> 269360 is not a file system superblock
> 359136 is not a file system superblock
> 448912 is not a file system superblock
> 538688 is not a file system superblock
> 628464 is not a file system superblock
> 718240 is not a file system superblock
> 808016 is not a file system superblock
> 
> ....
> 20813728 is not a file system superblock
> 20903504 is not a file system superblock
> 20993280 is not a file system superblock
> 21083056 is not a file system superblock
> 21172832 is not a file system superblock
> 21262608 is not a file system superblock
> SEARCH FOR ALTERNATE SUPER-BLOCK FAILED. YOU MUST USE THE
> -b OPTION TO FSCK TO SPECIFY THE LOCATION OF AN ALTERNATE
> SUPER-BLOCK TO SUPPLY NEEDED INFORMATION; SEE fsck(8).
> # 
> 
> Any idea what I can do now?
> 
> I wrote a little program that opens /dev/ad2s1e
> 
> #include <stdio.h>
> #include <sys/param.h>
> #include <sys/stat.h>
> #include <sys/file.h>
> #include <sys/time.h>
> #include <sys/mount.h>
> #include <sys/resource.h>
> #include <sys/sysctl.h>
> #include <sys/disklabel.h>
> 
> #include <ufs/ufs/dinode.h>
> #include <ufs/ufs/ufsmount.h>
> #include <ufs/ffs/fs.h>
>  
> 
> #include <fcntl.h>
> #include <ufs/ffs/fs.h>
> main(){
>   int fd;
>   int k,i=0;
>   int buf[512/(sizeof (int))];
>   if((fd=open("/dev/ad2s1e",O_RDONLY)) < 0)
>       printf("error opening device\n"),exit(2);
>   printf("opened device\n");
>   while(read(fd,buf,512)>0){
>     for(k=0;k<(512/(sizeof (int)));k++){
>        /*if(buf[k]==FS_UFS1_MAGIC)
>            printf("UFS1 * %d\n",i),fflush(stdout); */
>        if(buf[k]==FS_UFS2_MAGIC)
>            printf("UFS2 * %d\n",i),fflush(stdout);
>        i++;
>      }
>     }
> }
> 
> 
> I'm not sure whether my approach is correct. 
> Anyway, the blocks I find with that method
> aren't recognized as superblocks either.
> 
> 
> --
> Chris Christoph P. U. Kukulies kuku_at_kukulies.org
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