Author Topic: Defragmenting  (Read 1125 times)

Offline Syntho

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Defragmenting
« on: November 26, 2018, 04:26:54 PM »
I haven't defragged a hard drive since the 90s. I've read that defragging an SSD isn't necessary. But I'm running SCSI drives on my 9600 machines. Should I defrag a SCSI drive every once in a while?

Offline FdB

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Re: Defragmenting
« Reply #1 on: November 26, 2018, 04:31:50 PM »
Not certain if it's necessary... but force of habit (on SCSI drives) I still do. Seems to make things a bit faster after many large file writes, re-writes and updates of image files as they move towards completion. (Perhaps more so with sound files?)
This Must Be The Place

Offline Syntho

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Re: Defragmenting
« Reply #2 on: November 26, 2018, 05:02:33 PM »
Another thing I just realized is that I use ASR to backup my OS after doing a fresh install and tweaking to the way I want. I wonder if when you copy and restore an image if the files are placed in a way that defragging wouldn't even be necessary, since maybe it copies/places the files in an area on the drive that makes most sense already. Hmm...

Offline IIO

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Re: Defragmenting
« Reply #3 on: November 26, 2018, 05:56:32 PM »
you can be sure about that: copying data to an image file and/or burning media will create 100% unsplit files. because an image is a fresh volume.
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Offline OS923

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Re: Defragmenting
« Reply #4 on: November 28, 2018, 05:51:25 AM »
Your computer reads the directory of all volumes into memory at startup. For every file it reads the information of the first 4 fragments. Every time you want to access fragments after those 4 fragments, it has to read this info from disk instead of memory. Then it starts to work like a Winblows computer and you lose a big advantage of Classic Mac OS. This problem goes away by defragmenting, also on SSD. Don't say that an SSD is fast enough and that you won't feel the difference. Every HD/SSD can do only a limited number of asynchronous calls per second.

Offline ELN

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Re: Defragmenting
« Reply #5 on: March 16, 2019, 01:41:46 AM »
If you are able to access the volume from a modern machine, you could use my machfs Python package to dump the whole file system then rebuild it (HFS only). This would clear out any nasty lurkers, and would probably be much faster than a native defragmenter.