[Tfug] fdisk sanity check

[Mike Morrell]

  I need to modify my partition table but I wanted a sanity check first 
so I dont hose everything.  It seems that Partition Magic screwed it up 
at some point.  If you look at the layout below you will see that Part 
Magic set the extended partition to stop at cyln 1870 but the drive has 
only 1869.

Disk /dev/hda: 15.3 GB, 15381159424 bytes
255 heads, 63 sectors/track, 1869 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start       End      Blocks          Id  System
/dev/hda1   *           1          6         48163+        16  Hidden FAT16
/dev/hda3                7         19        104422+      83  Linux
/dev/hda4               20        1870    14868046+  f     W95 Ext'd (LBA)
/dev/hda5               20        1525    12096913+  83  Linux
/dev/hda6           1845        1869    200812+      82  Linux swap

  I already reconfigured my swap partition to end at the right spot so I 
only need to change the extended partition end position.  I assume all I 
would need to so is fire up fdisk and delete the 4th partition, recreate 
it with the correct end cylinder, and reset the type to f.   Or, do I 
need to erase partition 4, 5, and 6 and reenter them all?
  To backup the partition table ahead of time I can use 'dd bs=512 
if=/dev/hda of=/dev/fd0/parttbl.bin' right?


Thanks,

Mike