Repartitioning Corrupts Partition Table (103102)
The information in this article applies to:
- Microsoft Windows NT Server 3.1
- Microsoft Windows NT Workstation 3.1
- Microsoft Windows NT Advanced Server 3.1
This article was previously published under Q103102 SUMMARY
Disk Administrator (and the FDisk engine it shares with Setup) writes
partition table information to the disk based on the disk's Cylinder-Head-
Sector geometry. For SCSI disks, this geometry is invented by the driver,
rather than being an inherent property of the disk. Windows NT follows a
relatively standard method of using a geometry that produces 1-Megabyte
tracks. However, other systems (or SCSI disks run with BIOS) can use
different geometries.
When a disk with multiple partitions is taken from one system to another
that uses a different geometry, repartitioning it with Disk Administrator
can cause the partition table to become corrupt. This problem occurs
because Disk Administrator aligns all partitions on track boundaries based
on the current disk geometry. If the partition table entry for an existing
partition is rewritten with a new starting offset, the data on that
partition becomes inaccessible.
You can avoid or correct this situation by editing the partition table to
set the partition starting sector and length back to its original value.
You can use the BIOS Parameter Block (BPB) in sector one of the physical
volume to determine the geometry, or you can use sector zero of the
partition, which also contains a BIOS Parameter Block, to find the starting
sector offset.
Modification Type: | Major | Last Reviewed: | 11/20/2003 |
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Keywords: | KB103102 |
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