HARD DISK STARTUP PROBLEMS

Symptoms

A Microsoft Windows NT-based or Microsoft Windows 2000-based server may not start up if its system hard disk is transferred to another computer that is a different model. For example, a user may transfer a system hard disk to a backup computer or may replace the computer's motherboard with a different model. The following error message may be displayed on a blue screen:
***STOP: 0x0000007B (0xF741B84C,0xC0000034,0x00000000,0x00000000)
INACCESSIBLE_BOOT_DEVICE

Cause

This behavior can occur because the drivers for the storage controller and other critical hardware components are not installed.

Resolution

To resolve this behavior, use either of the following methods:

* Use only the same hardware for the backup system. -or-

* Replace the problem hardware components with the same model and the same series.

Contact your hardware vendor for any hardware-related problems.

More Information

There are two kinds of startup drivers that are critical for Windows NT and Windows 2000: the storage controller driver and the display controller driver.

If the drivers for the new storage controller and the new display controller are not currently installed, Windows NT or Windows 2000 may not be able to start up correctly on the new system.

You can work around a storage controller problem by doing either of the following methods:

* If the system disk is a SCSI disk, use the same kind of SCSI controller in the new computer. -or-

* If the system disk is a IDE disk, use the same kind of motherboard with the same kind of chip set.

For the IDE controller, there are several different chip sets in the market, such as Intel, VIA, SIS, and ALI.

NOTE: Windows 2000 may use different IDE drivers, which does not enable you to transfer the IDE system disk to a backup computer with a different chip set.

In Windows NT 4.0, the system may start up even when transferred to a system with a different IDE chip because several kinds of IDE chip sets share the same IDE (ATAPI) driver in Windows NT 4.0.

To work around a display controller problem, use the video graphics adapter (VGA).

Hard Disk

WHAT IS A HARD DISK?

Once known as the Winchester drive, the hard disk or hard drive is an essential hardware that every computer desktop and server contain. And its functionality, is to store vast amount of digital data in a non-volatile form, so that data can be retained when the computer is powered off. Data is again accessed when the power is on.

HARD DISK APPLICATIONS

Hard disks is a growing storage medium, used in desktop computers, laptop computers, video recorders, game consoles, portable players and much more.

Based on the principles of magnetism much like cassette tapes and floppy disks, hard drives are not immune to failure. As such, it is important to take care of your hard disk, and use it carefully.

TYPES OF HARD DISKS

There are a few different types of hard disk but, other than its physical size, the different type of interfaces of the hard disk is the main difference.

Desktop Hard Disk Types: 3.5', IDE and Sata Interfaces

Laptop Hard Disk Types:2.5', 1.8', IDE, Sata, SCSI

Server Hard Disk types:3.5' Sata, SCSI

HOW DOES A HARD DISK WORK?

Internal of a Hard Disk

If you are to dismantle the hard disk drive by opening the top casing (after removing all the necessary screws), the first thing you'll see is a spindle holding one or a number of mirror-like hard rotating platters (commonly called data platter). The platters could be made to spin at an extremely high speed, technically between 5,400 to 10,000 revolutions per minute (RPM). An extremely thin magnetic coating is layered onto the surface of the platter that is polished to mirror-type smoothness.

The platter is usually made of glass or ceramic (modern platter may use titanium). Unlike a floppy disk, the platter cannot be bent or flipped and hence we coin it as "hard disk" or "hard drive". Commonly a hard disk contains 1 to 10 identical platters that are stacked in parallel to form a cylinder. There is usually one Read Write (RW) head designated per platter face, and each head is attached to a single actuator shaft which moves all heads in unison and performs a uniform synchronous motion during reading or writing of data.

Data on a hard disk is stored in microscopic areas called magnetic domains on the magnetic material. Each domain stores either a 1 or 0 value. Similar to a floppy disk, a hard disk records its data in concentric circles or tracks, which are numbered from the outermost edge to the innermost edge of the platter. These tracks are further subdivided into smaller units called sectors which typically store 512 bytes of data each. Zoning may be needed to further optimise the data storage as the outer circumference would normally pack more sector units than the inner circumference.
Read Write Head

The RW head is the key component that performs the reading and writing functions. It is placed on a slider which is in term connected to an actuator arm which allow the RW head to access various parts of the platter during data IO functions by sliding across the spinning platter.

The sliding motion is derived by passing a current through the coil which is part of the actuator-assembly. As the coil is placed between two magnets, the forward or backward sliding motion is hence derived by simple current reversal. This location of the platter (just like the landmark along the road) is identified and made possible by the embedded servo code written on the platter.

Hard Disk Interface(s)

There are a few ways in which a hard disk can connect/interface with:
•(A)dvanced (T)echnology (A)ttachment (Also known as IDE, ATAPI and Parallel ATA)
•(S)erial ATA
•SCSI(aka Scuzzy)

There are variants of each interface, and this article will not do justice to the different types of ATA, SATA and SCSI interfaces. Thus, it will only highlight the more common interfaces as used by the home user.

ATA (IDE, ATAPI, PATA)

ATA is a common interface used in many personal computers before the emergence of SATA. It is the least expensive of the interfaces.

Disadvantages

* Older ATA adapters will limit transfer rates according to the slower attached device
* Only ONE device on the ATA cable is able to read/write at one time
* Limited standard for cable length (up to 18inches/46cm)

Advantages

* Low costs
* Large capacity

SATA

SATA is basically an advancement of ATA.

Disadvantages

* Slower transfer rates compared to SCSI
* Not supported in older systems without the use of additional components

Advantages

* Low costs
* Large capacity
* Faster transfer rates compared to ATA (difference is marginal at times though)
* Smaller cables for better heat dissipation

SCSI

SCSI is commonly used in servers, and more in industrial applications than home uses.

Disadvantages

* Costs
* Not widely supported
* Many, many different kinds of SCSI interfaces
* SCSI drives have a higher RPM, creating more noise and heat

Advantages

* Faster
* Wide range of applications
* Better scalability and flexibility in Arrays (RAID)
* Backward compatible with older SCSI devices
* Better for storing and moving large amounts of data
* Tailor made for 24/7 operations
* Reliability