I came across a great post today that brought back so many memories. It’s a blog post on a data recovery blog that goes into detail about what the Master Boot Record on a hard disk looks like. It took me back to the days of messing around with Norton DiskEdit and finding out how disks REALLY work. Anyway, here’s the Partition Record Layout from the post:
Partition Record Layout
|00h||Byte||Boot flag. 80h if partition is bootable, otherwise 0.|
|01h||Byte||Starting head(0 to 254)|
|02h||Word||Starting cylinder (0 to 1023) & sector (1 to 63) number|
|04h||Byte||Partition type (07 NTFS, 06 FAT16, 0C FAT32)|
|05h||Byte||Ending head number (0 to 254)|
|06h||Word||Ending cylinder (0 to 1023) & sector (1 to 63) number|
|08h||Dword||relative sectors to start of partition|
|0Ch||Dword||Total number of sectors in partition|
Okay, I never really went very far in messing around with partition tables, but the blog I took the post from is for a company called DTIData and from the post you can tell that they really know what they’re talking about. I looked a bit further into the website and learnt that they’re one of the few data recovery companies around with a class 100 clean room. This means that the room has less than 100 0.5 µm particles per cubic foot of air. Just to give you some perspective, normal air has around 35,000,000 particles per cubic meter.
They’re an interesting firm that seem to have a good selling proposition. They offer free upfront flat rate price quotes on single hard drive data recovery and also offer a data guarantee and all single hard drive recoveries are no data no charge (unless you tamper with the drive). They also recovery Exchange disks and perform RAID data recovery. Believe me, when you lose data, you can get really desperate, so a data guarantee can make all the difference for you. Interestingly, they have written their own software for data recovery and this is available for sale on their website. All in all, a pretty comprehensive data recovery company. Have you ever had a disk that needed a data recovery expert?