[Coco] Can an OS-9 disk get fragmented?

[Mark Marlette]

At 11:21 PM 3/25/2005, Allen Huffman wrote:

Al,

GREAT INFO! Where are these programs today?

We can't loose these great utilities.

???

Mark
Cloud-9

>The OS-9 file system, RBF, can get fragmented as easily as anything else 
>out there.  It's probably a more complex file system than DOS, so maybe it 
>has the potential of even more fragmentation.
>
>There were a number of utilities to defrag a CoCo OS-9 drive.  First, some 
>terminology:
>
>Defragment - make all files into one chunk.  You can degragment all the 
>files, but the free space can be horribly fragmented, causing 
>fragmentation to start happening immediately.
>
>Optimize - grouping files and directory sectors together in such as way 
>that the drive has to do fewer and smaller seeks to get all the parts of a 
>file/directory.
>
>Now, the utilities that were made for the CoCo include:
>
>Burke & Burke's FSR (file system repack) -- this was the BEST 
>optimizer/defragger.  On my old 20MB drive, after a complete defrag (which 
>could take 20+ hours!) the drive was SILENT -- until fragmentation set 
>back in.  It would put the FILE ID sector and then the file segment list 
>and then the sectors of the file or directory all back to back -- VERY 
>SWEET.  This one was the best, but massively time consuming.
>
>Burke & Burkes compactor -- I forget the full name, but it ran on a 
>graphics screen and was MUCH faster, but didn't optimize.  It reduced 
>fragmentation and packed things together so all the free space was at the 
>end of the disk.  Nice.
>
>JWT's Optimize Utility Set - Jordan Tsvetkoff had an EXCELLENT set of disk 
>utilities for OS-9 (must have, must have, right up there with dEd, the B&B 
>utils, etc.).  "optimize" would RAPIDLY run through all the files on the 
>disk and degrag the files (not touching the free space).
>This was awesome... But... did you know:
>
>OS-9 defrags by itself.  If you open a file, and specify that you want 
>200K, it will find a 200K contiguous block of sectors for you.  So, if you 
>want to defrag, you do this:
>
>open file A
>get file A size
>
>create file B with size set to size of A
>read from A
>write to B
>close A
>close B
>delete A
>
>...that little trick (which is why DSAVE defrags) is what optimize did -- 
>real slick.
>
>There may have been other utils but I never heard of them.
>
>There were utils to repair the bitmap/DAM (disk allocation map), set bits 
>(sectors in use), clear bits, etc.  Armed with these tools, and dEd, I 
>could just about repair anything -- got real good since my HD crashed all 
>the time...
>
>I wiped out the CompactFlash card I had a few months ago -- found a tech 
>manual for OSK on the net (same format, basically), and used dEd to bring 
>it back.  I really like the RBF file system.
>
>                 -- Allen
>
>
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