[PLUG] Partition table editing

[Robert Kopp]

Previously I mentioned difficulties I had with an inconsistent partition table that prevented me from using gparted. I fixed it and then made it worse again; at present it looks like this:

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
104 heads, 52 sectors/track, 361228 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xa8a8a8a8

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb2       235352062   782227455   273437697    5  Extended
/dev/sdb5       235352064   245116927     4882432   82  Linux swap / Solaris
/dev/sdb6       245118976   293956512    24418768+  83  Linux
/dev/sdb7       293947392   782243003   244147806   83  Linux

I was able to see in in gparted until I used Partition Table Doctor (a Windows application) on it. PTD noted slight gaps between some of the partitions (logical) and offered to "correct" this. What I have now is sdb7 going slightly beyond the end of sdb2 (the extended partition) and sdb6 and sdb7 also overlapping slightly. Exactly how could I fix this? I know that fdisk doesn't make permanent changes before "w" is issued. Do you have to delete all the partitions before re-creating the table? Or can you just change the offending one? Changing sdb7 alone, at both ends, would correct the overlap. Also, I note that in no case is there a gap of only one sector from one partition to the next. How large should it be, and how accurately do you have to estimate it?

 
Robert "Tim" Kopp 
http://analytic.tripod.com/