Defrag on Mac? Hard drive cleanup?

Due to the way OS X works, with minor exception, defragging isn't required. To delete an application, drag the application icon to the garbage can and empty the garbage.

If you want to see the files that are taking up space, download this: http://www.free-mac-software.com/whatsize/ . This program will allow you to sort all the files on your system by size.

If your wife only uses a few languages, you can use the program monolingual to remove unused languages, and there may be alot, that come standard with OS X. Be sure to keep English ... choose languages to keep or delete carefully. You can pick up up to 1GB of space depending on your options. Available from http://monolingual.sourceforge.net/

Also run the disk maintenance software OnyX, available from http://www.titanium.free.fr/download.php?sid=17d64f0e8b52277debd24503e87e2361 . Run the tasks on the cleaning and maintenance tabs. This may help with disk space and should help performance.

Of course before deleting files or running a disk maintenance program, you should have a hard drive backup.

You may find some other useful space-saving tips here:

http://www.thexlab.com/faqs/freeingspace.html

blueghoti:

If the HDD is near full, even after you dump some stuff, defragmentation may be helpful. You need to maintain a minimum of 5 GB of the total disk capacity on HDDs 40 GB and less, and 15% on HDDs over 40 GB as contiguous (unfragmented) free space to allow for swap files and allow for directory expansion. To run tighter than that risks directory corruption as the Extents Overflow file needs contiguous space to lay down new pieces. If it does not find the space it will overwrite extents that already have data resulting in overlapping volume structures, which results in data corruption, even if you use a utility like Disk Warrior, TechTool Pro or DriveGenius to rebuild the directory.

For defragging both Tech Tool Pro and DriveGenius hacve defrag tools, or you can get a dedicated tool as iDefrag.

In the long run a larger capacity HDD may be the best solution.

😉 cornelius

There's an application called [Show Volume Fragmentation|http://www.macupdate.com/info.php/id/18451/showvolumefragmentatio n] that just reports fragmentation. Read the reviews. The other thing is that pretty much any drive will show some fragmentation, even one just defragmented. You also need to know how to read a utility like this and don't let it scare you into thinking you absolutely have to defragment.

The easiest and cheapest way to defragment is to clone (Carbon Copy Cloner, SuperDuper!, others) your drive to another drive, wipe the original drive, then clone back. Files are automatically defragmented when copying provided the target drive has sufficient free contiguous space.

One note about running maintenance tasks using a utility tool. This will clear up space that will probably be taken up again soon since some of this is used on a regular basis by the computer. In other words, the effect may be temporary so don't suddenly think, "Oh, look, 1 GB freed up, let's fill that up fast." If you discover it suddenly frees a huge amount of space then maybe you have other issues with your computer that are causing some runaway process to create huge log files.

The easiest and cheapest way to defragment is to clone (Carbon Copy Cloner, SuperDuper!, others) your drive to another drive, wipe the original drive, then clone back. Files are automatically defragmented when copying provided the target drive has sufficient free contiguous space.

I have heard and read this, too. However, in another discussion thread baltwo, who is a moderator for the CCC forums, mentioned this option. I tried it with both CCC and SD. The result, was larger and fewer fragments, but not defragmentation. ( See this thread for a fuller discussion of defragmentation in Mac OS X). Doing sequential clones may get closer, but, although less expensive, will not be less troublesome than using a defragmentation tool.

😉 cornelius

I got incentive to do some investigating.

I examined my own hard drive, 115 GB (after formatting). I started off with about 14 GB free. I ran Speed Tools Defragmenter on it repeatedly until it no longer reported any files being defragmented, but still reported several hundred fragmented files. I kept on deleting large files and repeatedly running Defragmenter but it still wouldn't defragment all (according to Speed Disk's report).

This is ShowVolumeFragmentation (SVF) utility's report about half way through the delete large files and defragment again process, maybe when I had about 16 GB free. SVF also reported about 200 files still fragmented:

Number of freespace pieces >= 5GB: 0
Number of freespace pieces >= 1GB: 0
Number of freespace pieces >=500 MB: 1
Number of freespace pieces >= 100 MB < 500 MB: 1
Number of freespace pieces >= 10 MB < 100 MB: 1
Number of freespace pieces >= 1 MB < 10 MB: 5794
Number of freespace pieces < 1 MB: 19590

Below is SVF's report after I had removed more large (nearly a GB or larger) files (some of which had been on the drive, unchanged, since I first set it up) until there was about 20GB free. The report (not pasted here) still shows about 200 fragmented files. I'm puzzled because there's a 500GB chunk free and these files are mostly 2-20 MB mp3s and the like. Freespace piece distribution has moved around a bit, probably because defragmenting opened up some larger areas, but there's still a lot of bits and pieces.

Number of freespace pieces >= 5GB: 0
Number of freespace pieces >= 1GB: 0
Number of freespace pieces >=500 MB: 1
Number of freespace pieces >= 100 MB < 500 MB: 1
Number of freespace pieces >= 10 MB < 100 MB: 2
Number of freespace pieces >= 1 MB < 10 MB: 6745
Number of freespace pieces < 1 MB: 17996

Based on the report above (and other data not shown here) I saw I still had about 4 GB in freespace pieces <1 MB which made them nearly useless. I then decided to clone (not block clone) to an external, erase the internal, then clone back, all with Carbon Copy Cloner. Here's a SVF report after I did that:

Number of freespace pieces >= 5GB: 1 = 19.75 GB
Number of freespace pieces >= 1GB: 1 = 1.43 GB
Number of freespace pieces >=500 MB: 0 = 0 GB
Number of freespace pieces >= 100 MB < 500 MB: 0 = 0 GB
Number of freespace pieces >= 10 MB < 100 MB: 2 = 0 GB
Number of freespace pieces >= 1 MB < 10 MB: 3 = 0 GB
Number of freespace pieces < 1 MB: 62 = 0 GB

There is clearly a lot more contiguous space. The report shows 62 still fragmented files vs. the 200 remaining pre-clone. However, these files are largely only in 2 fragments each vs. the anywhere from 2 to 50 pre-clone. I'm still puzzled as to why some of my <10MB mp3 files were not copied onto contiguous space during cloning seeing as there's a very large contiguous chunk, but the situation has clearly improved as regards to fragmented freespace.

The Speed Tools defragmenting tool defragmented files but I think any decrease in the <1MB free pieces was only a side effect. Despite having 99.945% of the files unfragmented pre-clone I still had 4+ GB of pretty fragmented free space. Cloning only reduced file fragmentation to 99.985% unfragmented files but converted almost all of that 4GB to pretty much contiguous space.

Speed Tools defragments files but doesn't directly defragment freespace. The cloning process did take care of the fragmented free space, and apparently also some of the file fragmentation.

Now the question still exists, will I see any change in performance?

Edit:
Ran Speed Tools Defragmenter again. Took care of the remaining fragmented files.

Message was edited by: Limnos

Speed Tools defragments files but doesn't directly defragment freespace. The cloning process did take care of the fragmented free space, and apparently also some of the file fragmentation.

Interesting. I have Speed Tools, but never use it, and not for defrag.

The point of defragmentation in this context is to recover fragmented disk capacity as contiguous free disk capacity (free space). Speed Tools defragmented your files, which apparently reduced fragmentation. Cloning then completed the process of putting defragmented data into contiguous blocks thus creating contiguous free space. At least that is my best guess of what happened in your experiment.

Thanks for checking that out and reporting your results. Do you have any reflections on what happened?

😉 cornelius

The point of defragmentation in this context is to recover fragmented disk capacity as contiguous free disk capacity (free space).

That's the major objective in terms of extents as you have mentioned. Another thing is if a file is highly fragmented the drive may have to work a bit harder to find all the pieces, slowing things down a bit.

Do you have any reflections on what happened?

Probably pretty much as you said. Simply having ST copy the files elsewhere on the drive as part of defragmenting resulted in some of the file chunks between empty spaces being moved elsewhere and the space made contiguous. That's why I saw a slight improvement in 1-100MB free spaces simply by the movement of tiny file pieces allowing some of those tiny spaces to now become contiguous. Still, if the the space is also broken up by some unfragmented files Speed Tools doesn't do anything to them so the space remains broken up. Hence I still had 17,000 <1MB free space pieces with only 200 fragmented files. It was probably unfragmented files staying put that was still breaking up the space. It's not until you force those files to be copied that the simple process of copying ends up with them being placed contiguously and all tiny spaces made contiguous.

I don't know the details of drives and file systems. For some reason those final files weren't defragmenting until I truly made a large contiguous space by cloning. Maybe some of that pre-cloning contiguous space was reserved by the system and wasn't available for defragmenting. After cloning there truly was space available and the final defragmenting run defragmented all the rest of the files (with the exception of a few active system files since I was running it on an boot drive). I still wonder why they weren't copied on unfragmented though.

Not that I'm in a rush to try it, it would be interesting in seeing how effective cloning alone would have been in terms of defragmenting the files. For the files remaining after using ST the cloning process defragmented only about 70% of the files. There wasn't anything special about the remaining files. Some were mp3s, one was an application, one another media file.

Edit comment:
When I first started using ST defragmenter I had about 1600 fragmented files. I ran it a couple of times in succession until it wouldn't defragment any more files, and there were still 1000 fragmented files. Every time I deleted a large file (e.g., a 2 GB sparse image) it would go a bit further. So it is effective, but definitely won't go all the way on its own, especially if you really, really want to keep all your files. 🙂

You can get more help about Defrag Drive from here
http://support.apple.com/kb/HT1375

Either You can delete an unwanted App which you do not wish to keep on your Mac with the help of Stellar Speed Up Mac which provides an uninstaller which deletes your App from your Mac. Just it has a Drag & Drop facility to delete your un-needed software.

Message was edited by: allensood

You can get more help about Defrag Drive from here
http://support.apple.com/kb/HT1375

The article linked deals with disk optimization in a general sense, although it does have reference to the need for defragmentation in cases in the event of a too full drive or large files. If you check the thread I linked earlier you will find a more extensive reference to this article.

😉 cornelius

Thanks cornelius, I do appreciate this...