Optimizing Apple Mac OS X

[kattman]

In theory, any operating system installed on a partition formatted HFS + (which is the case of Mac OS X) tends to fragment. This is an inescapable rule! Mac OS X thus not immune to this rule. Therefore, as you use OS X for its daily work, the system and the files it contains is fragmented and, gradually OS X becomes more heavy.

Well, that's the theory! But just think that Apple precise HERE few interesting elements:

• Nowadays hard disks are much larger than in the past. Thus the HFS + avoids whenever possible the reuse of space previously used by deleted files.
• MAC OS X 10.2 and later include an allocation system to bring together in one place the disc a number of small allocations. When you install Mac OS X, many files are placed in a special area ( "hot band") can be read quickly and defragmentation could move those files, which could slow down the boot.
• PANTHER, TIGER and LEOPARD can automatically defrag some files (the files small and medium size) in a process called "Hot-File-Adaptive-Clustering."

Also according to Apple, there would therefore be of little interest to defragment your hard drive! However, if you feel the need to defragment, APPLE suggests at first simply restarting your Mac! As against, if your hard drive is copiously filled and / or if you regularly create or edit large files (video etc ... - which is increasingly common nowadays -) in this case APPLE states still it may be necessary to defragment your hard drive with appropriate software.

[kattman]

Many people (who believe sometimes hold infuse science) who feel that due to the UNIX Mac OS X, this defrag has become totally useless. Others argue however that even if OS X has a UNIX kernel, the system is actually installed on an HFS + partition, which it inevitably leads to fragmentation

Companies publishing software as TechTool Pro, Drive Genius "or" iDefrag "they believe there is indeed fragmentation:

MICROMAT:
"TechTool Pro" offers a new optimization feature for your disk drive. The Mac OS X system contains thousands of files that fragment quickly. TechTool Pro allows you to defragment files that your system operates at its maximum potential."
"Micromat strongly recommends leaving at least 15% free space on your volume OS X. If 85% of an HFS + volume is filled and highly fragmented, any new data added to the volume can damage the disk directory"
"The file swapfile must be written to a disk location that must be both free and contiguous."

"To use a hard drive at maximum performance, it must be defragmented regularly. It is very important, especially if you do video editing or manipulation of audio files. When a file Media is fragmented, it is possible that the disc can not read or write the file fast enough. This will penalize the operating software. Optimization changes the way the data are positioned, and improve disk performance. After optimization, the files are stored in contiguous, starting from the "beginning" of the disc which is the fastest. "

PROSOFT:
"Create and delete files on your hard drive contribute to fragmentation. When the system writes files on the disc, looking for empty slots. If a site is too small to accommodate the file, then it writes a part of the file here and another elsewhere. This fragmentation leads to a gradual slowdown of the disc, because it must constantly scan the content to pick up the pieces of files. Use "Drive Genius" to defragment the hard drive is an excellent way to increase performance of the computer. "Drive Genius" puts all the pieces in a block adjacent to the remaining free space. "

CORIOLIS:
"Every user has noticed, little by little the system becomes more broken. This is especially true with frequent updates. This contributes to fragmentation. Moreover, the operating system itself ends up disperse throughout the disc, so that your computer takes longer to boot, applications, more time to get started and you need more time to your work. "
"Some people say that HFS + avoids fragmentation, this is true, but only for files of small and medium sizes, not for large files, or the free space on the disc. This poses a real problem on Mac, because the swapfile is no longer necessarily contiguous on the disc if the free space is fragmented. "

[kattman]

To defragment your OS X system on a periodic basis (the notion of periodicity of course varies according to each type of configuration, use more or less intensive applications, installations and uninstalls frequent ... etc) you will find on this page 4 solutions for defrag, defragmentation applications to be used either from the bootable OS X CD that came with those applications, or (even better if possible) from a second partition OS X (clone for example) - see "Installation" .
The final solution is simply ... cloning.



1 - TechTool Pro: a tool that has proved its worth

Download latest version of TechTool from here.

This is an excellent tool and is undoubtedly the current reference in the field of software essential for your Mac. "TechTool Pro offers many features for maintenance, repair and optimization. As we are discussing here the issue of fragmentation, we will develop this function proposed by TechTool Pro

Remember to defragment your OS X partition, you must either boot from the CD that came with "TechTool Pro, or start a second OS X partition (your clone for example) or even (and this is is an advantage of TechTool Pro) start on the eDrive.

A "eDrive" is a boot partition containing emergency "TechTool Pro. To create this "eDrive" run "TechTool Pro and go to the" Tools. "Once this partition" eDrive "created, you'll even forget, because it is invisible! You can however at any time select "TechTool Pro" to start your Mac on it and proceed to repair and optimize your OS X partition

Note: If you have a bootable clone on a partition on your external hard drive, do not you create a "eDrive. Just start on your clone to verify / repair your main OS X volume.

To proceed with the defragmentation of a partition or a hard disk with "TechTool Pro, run the software and go to" Tools. "Two operations optimization are proposed:

Optimizing Files:
This test allows the defragmentation of files. Mac OS X when writing data to disk, it may have to split a file into several pieces. We then say that it is fragmented. This feature allows you to combine data from a file on successive blocks of the hard drive.

Optimization Volume:
This feature allows defragmenting the disk. After making the optimization file, the files are continuous, but may not be placed one after the other, creating "holes" empty. To improve disk access, it is better to stick the files to each other at the beginning of the hard disk.

It is therefore preferable to start as a first step "Optimizing Files" and then in a second time "Optimizing volume". See it a little more detail:

a) Select the "Optimize Files" in the lower left to the "Selection Tool" and select a volume on the right. Two buttons are available:

- "Previous Optimization" which displays an overview of the status of files, without starting the defragmentation
- "Start Optimization Files" lets you actually defragment the files.

Click the "Start Optimization Files" to start defragmenting files.

b) Now select the "Volume Optimization" at the bottom left to the "Selection Tool" and select the volume that you optimize the files. Two buttons are available again:

- "Previous Optimization" will display a graph representing the state of your disk / partition:

On the left of the graph, you will find a summary of the data from your disk / partition:

• Used: Size of data that are stored on disk.
• Free space: empty space on the disk.
• Largest free space: The size of the largest contiguous free blocks on disk. If the system or the user wants to write a larger file (here a file larger than 780 MB, then it is fragmented).
• free contiguous blocks Number of blocks occupied and non-contiguous.
• Fragmentation space: Less contiguous free space is fragmented, the less the need to fragment the new files on the disk will be important.

The graph on the right shows the condition of your disk / partition. At left, the beginning of the disc at the right end of the disk. The green represents the free space, the red space. The size of the bar graph shows the amount of data to a location. In the picture above, one can see a very fragmented disk with little free space.

Click the "Start Optimization Volume" to start defragmenting volume.


Once "Optimization Volume" is complete, you get a graph like this:

[kattman]

2 - DRIVE GENIUS: A GOOD ALTERNATIVE

Here is also a very comprehensive software for testing, repair, and of course defragment your volumes. "Drive Genius" is also regarded as the major competitor of TechTool Pro. The functions offered by these two programs are very similar.

As "TechTool Pro, you will need to install" Drive Genius "on another partition (and boot from this denière) or boot from the CD" Drive Genius "defragment your partition for OS X.

You can get "Drive Genius" form HERE

To start a defragmentation in "Drive Genius", select "Defragmenter" in the main window, "Drive Genius", then choose to defragment the volume in the left column.

Which appears in yellow is already defragmented
which appears purple in color requires defragmentation
which is black is the free space.

Click the "Start" button.

"Drive Genius" when the program launches defrag your volume. When finished, it tells you that the defragmentation operation is successful.

"Drive Genius" also offers a very interesting (but I do recommend that users) to resize your partitions on the fly.
You just need to select "Partition" in the main window of "Drive Genius".
You can then add / remove, make the invisible visible and resize your partitions to suit your mood and your available disk space. You can also change the location of the partitions on your hard drive.

Note: It is necessary to boot from another volume or CD, because you can not resize / modify the partition on which you booted.

[kattman]

3: iDEFRAG, an interesting tool

"iDefrag is a small program that does one thing defragment. Its price is more modest .

This software has my preference, because as stated Coriolis "iDefrag" has the advantage of being fully compatible with the "Hot Band" specific to Mac OS X, which seems to be likely to meet the concerns of some users . iDefrag "is the only software to take into account this specificity.

The demo version only allows you to defragment the partitions less than 100 MB You can download the demo version (or buy the software) from HERE.

The originality of "iDefrag" lies in the fact that the software offers 5 different defragmentation algorithms:

• Compact: All files are moved to the "beginning" of the volume.
• Metadata: This algorithm is based primarily on the metadata files. Metadata is better protected and optimized.
• Quick-on-line: To defragment a volume without the "dismount." That is possible only for certain files only.
• Optimize: Allows you to rearrange the files on the volume.
• Full Defrag: Lance algorithms the "Metadata" and "Optimize".

I advise you to use the algorithms "Compact" or "Full Defrag" for a defragmentation optimized.

To use "iDefrag", select the volume to be processed and click "Go",thing is easier.

[kattman]

4: SIMPLY THE CLONING

Yes, if you do not have defrag software, but if you have rather a cloning software (my preference is for "Super Duper" ), you indeed quite possible to defragment your hard drive using the technique of cloning.

How?

1. Clone your main OS X partition on another partition (preferably on an external hard drive)
2. Start on this clone and clone the clone, this time to your main OS X partition, taking care to clear before the latter ( "Super Duper!" Allows this).
3. Restart your main OS X partition

Then you will enjoy a substantial gain of responsiveness!

NOTE: It is important to take into account this cloning back is a problem Indeed, some software needs to be enabled to work remotely. It is sometimes necessary to disable the registration of the software before the operation in return for cloning and then reactivate at a later date.

I recommend you also use the excellent utility maintenance "Leopard Cache Cleaner." This allows the "Optimize" under "System", optimize / defragment files (case " Optimize Files ") using precisely the internal OS X defrag described above

NOTE: To enable this feature requires the "Logging" is enabled.

Should we launch this operation often defragmentation?

It depends of course on the configuration of each (size of the hard disk, file number, intensity of use etc ...).
For my part, I run this very useful about 3 to 4 times a year. This enough, we are no longer under OS 9.
So if you have a good time to less or more run a good defrag!

[kattman]

LEOPARD AND FUNCTIONS "UPDATE_PREBINDING" / "dyld"

In Mac OS X PUMA (10.1), it was necessary to optimize the system regularly by launching the "update_prebinding." This could be initiated manually from the "Terminal", or through applications such as small "Xoptimize" or "SpeedMeUp Pro" that did for you.

With Mac OS X Jaguar (10.2), things became different and much simpler yet! Because, according to the explanations provided by the publisher of "Xoptimize", available here, and this function "update_prebinding" became fully automated in OS X and the system itself which launched this operation when this is necessary.

And yes, as explained in the editor "Xoptimize" it was no longer necessary to manually run this function "update_prebinding" under OS X, as the system takes care of everything! This is under Jaguar 10.2, Panther 10.3 and Tiger 10.4.

10.5 under Leopard, things have changed since this command update_prebinding "has become obsolete and was replaced by an operation of updating caches shared" dyld ".
"dyld" a pitcher is responsible for loading dynamic frameworks, and bundles dylib required by a process. This option allows you to update the caches used by dyld and sometimes fixes problems. You can run this update caches shared "dyld" with "Onyx"