Advanced Format

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Contents

The Technology

Hard drive manufacturers have moved to a new standard: 4KB (4,096 bytes) sectors, replacing 512B sectors. This is a good thing; it means that the signal-to-noise ratio improves, and less space is needed for error correction. Long-term improvements in speed, density, and overall capacity. Western Digital has started releasing drives with 4KB sectors under the name "Advanced Format" (not to be confused with the Advanced Forensic Format).

The Problem: Death of LBA 63

Operating systems written before the transition, particularly XP, have trouble with the new drives. XP makes an assumption about where the format should start (LBA 63), but this doesn't work well with the translation software that maps from logical 512B blocks to physical 4K blocks.

The nutshell is that XP should not be used to format these drives, and some assumptions made by tools and users need to be corrected. For analysis purposes, note that you can't assume that an NTFS partition starts at LBA 63. If you are used to using, for example, the Sleuthkit command "fls -o 63 <image>", this may need to change. Hopefully more information about these drives will come forth as time progresses.

The Solution

To format one of these drives properly for Windows XP, use the following utility (this applies only to drives from Western Digital):

Western Digital Advanced Forensic Drive Format Utility

Links

A Good Overview at AnandTech PDF White Paper A Tom's Hardware Review of the WD Caviar Green Drives