Next: Source Code
Up: Disk Optimization Simulator
Previous: Assumptions
There are several differences between my simulator, real
disks, and real disk defragmentation software.
- 1.
- I assume that all tracks have the same number of
sectors. This is not true of real disks.
- 2.
- All tracks and sectors are treated identically.
There is no differentiation between sectors holding
boot data, directory entries, file system metadata,
or data.
- 3.
- Simulator allocates disk space assuming one
cluster equals one sector. Multiple consecutive
sectors would have to be specified in the input file
in order to emulate clusters of more than one sector.
At present, there are two situations which can lead to a
segmentation fault in the simulator.
- 1.
- Simulator will crash with a segmentation fault
if the number of sectors selected by the user is less
than 3. This isn't really serious since there should
not be any disks with so few sectors per track.
- 2.
- Simulator will crash with a segmentation fault
if the number of sectors required to hold all of the
entries in the input file exceeds the number of
sectors available (based on the number of tracks and
sectors specified by user).
As shown by the simulator's help screen, these are
the command line arguments that the simulator accepts:
--help this screen
--in <filename> read from input file <filename>
--out <filename> output to output file <filename>
--tracks <numtracks> disk has <numtracks> tracks
--sectors <numsectors> disk has <numsectors> sectors
--policy <type> specify policy, where <type> is
1 for everything at beginning
Next: Source Code
Up: Disk Optimization Simulator
Previous: Assumptions
Barnett Hsu
1998-10-31