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3]DISKOPTI: Disk Optimizer
3]By Claude Abraham
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     This program will copy an entire disk in a way that allows the files to
be read faster by rearranging the data blocks.
     In normal use, when the system writes files on a disk, chances are the
data blocks allocated for this file won't be contiguous but spread all over
the disk. This is why why we hear the disk drive's head go back and forth
when the file is reread. It then takes more time to read the file and adds
wear and tear to the disk drive mechanism.
     DiskOpti will copy all the files on a disk, making sure the data blocks
for each file are consecutive. Depending on the number of directories and
files on a disk, the process can take up to 6 minutes to complete.
     Usage of the program is straightforward, place the disk to be optimized
in one disk drive and a formatted disk in another drive, then select the
appropriate menu selection, as example:

df0: -> df1:

. . . which means the source disk is in df0: and the destination disk is in
df1:. Then wait until the process is complete.
     In the Project menu you will find the List and the Save options:
     List: Will make a list of all files, directories and headers of the
source disk. No copying is done.
     Save: Save the list either on the prt: device or on a file.
     You can also do a save after the disk as been optimized.

     The list is divided in 8 columns:
  1- Header block number of the file or directory.
  2- Root block number.
  3- Block number of a file with the same hash code of the current file.
  4- If the file has more than one header block (uses more than 72 blocks),
     block number where the block list continues.
  5- File or directory header block position in the parent directory
     (between 24 and 308).
  6- Total number of blocks used for this file, including the header block.
     This number is always 1 for a directory.
  7- 0: if its a directory or 1: for a file.
  8- Name.

     All this information can be useful for those who like to look at the
data directly on the disk's blocks.

3]TESTING RESULTS
     Try this test to check the improvement of an optimized disk.
     -- Select a disk that has a number of drawers with icons.
     -- Open all the drawers after you make sure the write protect tab of
the disk is off. This is very important.
     -- Do the same with the optimized copy of the disk.
     -- Now measure the time it takes for the icons to appear when you open
the disk icon of the original disk.
     -- Do the same for the optimized disk.
     -- Compare both timings. The more icons are on a disk, the more the
gain. Some times as much as 100 percent.

     This program works either from the Workbench or the CLI. It is entirely
written in assembler for faster operation and smaller size. You can also use
the included DiskView program to look at the position of the file and
directory blocks on the disk.

3]BENCHMARKS
     Here are some benchmarks done with different optimizing programs and
the DiskOpti program. The AmigoTimes 1.1 disk was used for the test.

1- Original disk.
2- Copied with Disk Mechanic's Tune_Up using the CLI FILE COMPLETE option.
3- Copied with Disk Mechanic's Tune_Up using the WB DRAWER COMPLETE option.
4- Copied with the "copy df0: to df1: all" command.
5- Copied with DiskOpti.

Tune_Up is copyright Lake Forest Logic Inc.

                        -1-     -2-     -3-     -4-     -5-

Copying time                     65      37     8.5     5.1     in minutes

Time to open
disk icons      (10)    9.8    12.8     4.2    10.3     4.4     in seconds

Virus_Killers   (2)     2.9     3.2     2.1     2.1     2.3

Programs        (9)    10.6     ***     4.7    10.7     4.7

Pictures        (3)     3.3     3.6     2.5     4.2     2.6

Terminal        (5)     5.1     ***     2.9     6.3     2.9

Demos           (2)     2.9     3.9     2.2     4.2     2.1

Tools           (8)     6.6     7.7     3.7     7.6     4.5

"Dir opt a" command    20.6     ***    24.5      38    28.3

Load ArkDemo           17.6    26.7    25.1       *    18.8

Load MacAttak.pic      14.7    14.5    16.4    17.1    14.3

You read correctly, 65 and 37 are in minutes....
***: Guru...
*:   Did not work.

3]CONCLUSION
     I still have to work on the program to make the Dir command faster
while keeping the other timings the same. For the rest I will let you make
your own conclusions.
     All comments, questions and suggestions are welcome.
     Claude Abraham, 1999 Place Jules Leger, St-Bruno, QC, Canada, J3V 5M6.

4]END OF TEXT