Messages in this thread | | | From | "Dave Cinege" <> | Date | Wed, 11 Jun 97 15:39:14 -0500 | Subject | Re: *Help!* Where is device partition info stored by the kernel? |
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On Wed, 11 Jun 1997 15:20:41 -0400 (EDT), Grant R. Guenther wrote:
>> Where does the kernel keep the partition info? I looked all in /proc and >> couldn't find it. > >There's an array indexed by the minor number inside each block device >driver. Look for the fields "start_sect" and "nr_sects" in the source of >the driver in question. > >> The system HAS NOT been rebooted. I can still mount all of my partitions, >> but the second it goes down everything will vanish. The kernel still knows >> the old (correct) layout, or else it would not be mounting things. Where is >> it hidden? > >There's probably a better solution, but at worst you could write a little >program to use the BLKGETSIZE ioctl to extract the _size_ of each >partition, and then deduce the layout from that.
This is what I figured......I've yet to sit down and actully write anything for linux so I wouldn't know where to begin. By the time I shit!
Just had an idea....if I dd the partitions to /dev/null it should give me the size of each! I believe they are spaced 63 sectors apart from that point, so I should be able to work from the end of the drive back....
What I was saying, is it would take me more time to write that program then back everything up, repartition, and restore.
>As a backup solution, you might use dd to capture the first physical >block of each of the lost partitions. Take a cksum of each of them, >then you can devise some offline method of searching for blocks >on the disk that have that cksum.
I thought of this, but the data is not worth the work. Basically everything is from a virgin install and set-up so it is a matter of how much time I can save.
My new dd idea should work. Will take a little time, but it will work. I was hoping someone would say "Look here in proc" or "This new version of fdisk will print that info"
That info really should be available somehow at the user level.....
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