diagnostics

Diagnostics-General Overview

This set of functions are the heart and soul of the Drive Master 2000 file system recovery suite. It allows the technician to scan the current file system for any anomalies and pinpoint problems.

This set of functions must be executed FIRST, before any additional file system repair can be implemented.

Build Physical

This function scans the system for all hard drives that are registered with the BIOS.

It is not scanning for drives C, D, E etc.... but for the actual physical drive.

For example, the system may have one hard drive (physical) in it, but the file system contains two (logical) drives designated C and D. The scan does not look for CD-ROMS, Tape systems, or other peripheral other than hard drives registered in the BIOS.

You must build the Physical Drive before choosing the drive to work on in the next step. We often get calls that the software will not allow them to choose a drive. They have skipped this step, and have not built the list in memory! (there is nothing to choose! the software hasn't tested anything yet!

Choose Physical

Allows you to choose which physical drive to work with.

Drive Master 2000 only looks at the first two physical drives in the system. If any more exist, they are ignored.

Tech Tip: If a drive is in need of data recovery we always recommend that it be moved to a test system, with perhaps one other clean drive to move data to incase of physical damage to the first drive.

The PID is the actual physical drive number.

80 is the first physical drive.
81 is the second physical drive.

The box next to the PID is the physical drive number and a drop down list. Just click on the box (80) and all the currently found physical drives will be displayed.

Pressing the Okay button activates the currently selected physical drive.

Build Logical This is the next step in determining the extent of damage, if any, on the current file system. Just as Build Physical scans the system for all hard drives registered with the BIOS, Build Logical scans and tests all the registered hard drives for logical drives. A logical drive is defined as a partition on a hard drive. In other words, a physical drive, may be divided into many logical drives designated as C, D, E etc. It is not uncommon for the data to be fine on one logical drive, and damaged on another even though they reside on the same physical drive. The process for scanning and building the logical drive list consists of Four phases. They consist of: Phase I Scan and Build Partition table list Phase II Boot Record Testing and Typing Phase III File Allocation Table (FAT) testing Phase IV Geometry Alignment testing After this testing, you will be able to evaluate which drive(s) have file system problems, and can then choose which (logical) drive (C,D,E, etc) to work on. Phase I - Scan and Build Partition table list Phase I of the recovery process looks at all registered physical drives on the system. Through a series of rigorous tests Drive Master 2000 determines if the current partition table structure is intact. During the testing and recovery process this windows will be displayed and gives a step by step status. NOTE: Some repair is being done in memory at this point. We are not writing to the disk! (Drive Master will always warn you before writing any information to the drive) If the structure is found to have possible corruption, a set of time tested algorithms are applied to reconstruct the original structure. During the reconstruction process some questions are asked in order to assure a complete and accurate file system recovery. The possible questions and expected answers are as follows: Is the current drive formatted as a Compaq drive? Compaq drives maintain a diagnostic partition on each of their systems. The diagnostics are specific to each Compaq system and therefore it is logical that the partition exist. However, in the world of file system recovery this diagnostic partition is considered non standard and is handled as such. In order to ensure that the partition table structure is properly reconstructed it is important to answer this question correctly. There are several things to keep in mind when answering the above question. 1. Does the drive exist on a Compaq system? 2. If the drive exists on a Compaq system have any utilities been executed to delete the diagnostic partition? 3. Was the drive originally on a Compaq system but then transferred to a non-Compaq system? Is the current drive formatted as a single partition? If the physical drive has been repartitioned by fdisk or any other drive utility, the original partition data may still exist on the drive. This can lead to false partitions and possible data corruption. If the drive has more than one logical drive (C, D, E, etc.) then the answer to the above question is NO. However, if you only have a C drive then the answer to the question is YES. A NO answer executes a drive scan that will closely examine the physical drive for existing partitions. If a partition is discovered a window will be displayed. The partition size as well as the cylinder will vary from physical drive to physical drive. It is important that this question be answered correctly to help ensure recovery.

	Phase II Boot Record Testing and Typing After the partition table structure has been scanned, listed, and for corrupt structures, recovered, Drive Master 2000 tests the Boot Records for each partition or logical drive. During the testing and recovery process this window be displayed. It gives a step by step status of the boot record scan and reconstruction. If the boot record is found to have possible corruption, a set of time tested algorithms are applied to reconstruct the original boot record. During the reconstruction process some questions are asked in order to assure a complete and accurate boot record recovery. The possible questions and expected answers are as follows: Will this version of Windows support the FAT32 File System? This question helps determine which version of 95 the you are currently running. If you have an older version of 95, that is pre OSR2, then the answer to this question is NO. Any version that is OSR2 and later, including 98, will support FAT32 and the answer to the question is YES. Has a FAT16 to FAT32 conversion utility been used on drive '?'. In order to align the file system structure properly it is important to know if a third party utility, or a non-Microsoft partitioning utility was used to convert a previously FAT16 file system to a FAT32 file system. If a utility of that type was used the answer to this question is YES. However, if the FAT32 file system was created with fdisk, or some other Microsoft utility, then the answer is NO.


	Phase III File Allocation Table (FAT) testing The FAT is the map to the rest of the file system structure. If the data is corrupt in this area then the entire file system may be skewed and recovery, although not impossible, becomes increasingly difficult. Unlike Phase I and Phase II where the file system structures were rebuilt immediately (in memory), the FAT phase only tests. There are other functions in Drive Master 2000 that allow for the reconstruction or the FAT, as well as the Root directory. (they are described in the File System Component Recovery section) During the testing process this window will be displayed, and gives a step by step status of the FAT scan . It is important, although not crucial, to keep a watchful eye on this windows progress.
	Phase IV Geometry Alignment Testing The geometry of a physical drive is one of the key elements in ensuring that the file system structure is in correct alignment. Many times the Head, Sector, and Cylinder of a hard drive may be wrong, or corrupt. This test determines: 1. The Head, Sector, and Cylinder information found in the CMOS as well as any translation from BIOS to BIOS is consistent with the current file system structure. 2. If any file system reconstruction was performed during Phase I or Phase II questions were answered correctly. This Phase of testing scans the drive for certain keys to geometry. If one is found, then the correct counter is incremented. Locating 5 of these keys connotates a valid geometry and the testing is terminated. However, if a key is found at the wrong location, then the incorrect counter in incremented. If the incorrect counter exceeds 50 or more and the correct counter does not reach 5, this is a good indication that the geometry alignment of your drive is incorrect and it may be time to check the CMOS, BIOS type, as well as any questions answered during the phase I or phase II reconstruction. If the correct counter does not reach 5, and the incorrect counter is less than 50 it is possible that the geometry is correct, but only a few files reside on the logical drive. This window will appear if in this case: A special note The geometry testing may take several minutes to scan the logical drive.Although no activity may be seen on the screen, Drive Master 2000 is probably still hard at work. However, always check for drive activity via the drive light on the computer.