Ghost Switches: Drive detection

Products

• Ghost Solution Suite

Issue/Introduction

What switches are available for controlling how Ghost accesses the hard drives?

Resolution

Computers provide a variety of methods for accessing the hard drive. Several factors affect which methods are available on any particular computer: the computer's BIOS, the hard drive controller, the size of the hard drive, the make and model of the hard drive, and the capabilities of the program that needs access to the drive.

Ghost uses a variety of methods for accessing hard drives. The following table describes switches that allow you to control which method Ghost uses.

Switch	Function	Ghost Version
-FFI	Forces Ghost to prefer the use of the direct IDE access method for IDE drives. Direct IDE access is sometimes faster for IDE drives than other access methods.	All versions
-FFS	Forces Ghost to prefer the use of the direct ASPI/SCSI access method.	All versions
-FFX	Forces Ghost to prefer the use of the Extended Interrupt 13h access method.	All versions
-FIS	Prevents Ghost from making corrections when the BIOS fails to report the last cylinder of the disk. More information: During a Disk-to-Disk or Image-to-Disk cloning operation, Ghost calculates where the partitions will be located on the destination hard disk drive. This calculation is based, in part, on the disk access method that Ghost is using, which provides figures for calculating the size of the drive. The BIOSs on some computers do not report the existence of the last cylinder of a hard disk. When Ghost detects this inaccuracy, Ghost uses the disk size that is calculated from a different, safer disk geometry to avoid possible integrity problems. Using the size calculated from the safer disk geometry may leave several megabytes unused in the destination disk's partitions and cause small differences between the source and destination disks' available free space.	All versions
-FNA	Turns off asynchronous Input/Output. When -FNI solves a disk access problem, -FNA and -FNU can be used to help diagnose the disk access problem.	All versions
-FNI	Prevents Ghost from using the direct IDE access method. Use the NOIDE switch if you want to turn off all IDE access with Norton Ghost 2003.	All versions
-FNS	Prevents Ghost from using the direct ASPI/SCSI access method (an ASPI driver is necessary for direct SCSI access).	All versions
-FNU	This switch prevents Ghost from accessing the IDE drive by means of Ultra DMA and forces Ghost to access the drive by means of PIO instead.  When -FNI solves a disk access problem, -FNA and -FNU can be used to help diagnose the disk access problem.	All versions
-FNX	Prevents Ghost from using the Extended Interrupt 13 access method.	All versions
-NOIDE	Disables access to IDE devices.	Symantec Ghost 8.0 and Norton Ghost 2003
-NOSCSI	Disables access to SCSI devices via ASPI.	Removed from Symantec Ghost 8.0 and Norton Ghost 2003

Explanation of the term "disk geometry"
"Disk geometry" is the layout of the drive, that is, the number and location of the cylinders, heads, and sectors (CHS). Each disk has two or more valid disk geometries. The first is the actual (physical) number and location of the cylinders, heads, and sectors.

Other disk geometries consist of the number and location of the cylinders, heads, and sectors as reported by the disk access method that is in use. Most disk access methods "translate" the real CHS numbers into other numbers so that the operating system and programs can read and write to all sectors on the drive, regardless of the size of the drive.

Ghost documentation often uses the terms "disk geometry" and "disk access method" interchangeably. Which term is appropriate to use can normally be determined by the context. Generally, when Ghost documentation discusses the drive detection switches, the correct term to use is "disk access method." When Ghost documentation discusses the size of the drive or partitions, or the CHS values, the correct term to use is "disk geometry."