Q: proper maintenance and good diagnostics?

"Maintaining" OS X is not really necessary.  TechTool Pro is very expensive and probably not worth it.

Defragmentation is a Windows thing and not really an issue with OS X.

I personally don't trust any third-party disk or system utility.  If apple felt Defrag was needed, then that capability would have been built into Disk Utility.

Repair Permissions now and then if you feel like it.  That's built into Disk Utility, so it's safe enough.

Just use OS X.  It takes care of itself.

hotwheels,

The Safe Mac » Mac Performance Guide provides additional information.

How to maintain a Mac

1. Make redundant backups, keeping at least one off site at all times. One backup is not enough. Don’t back up your backups; all should be made directly from the original data. Don’t rely completely on any single backup method, such as Time Machine. If you get an indication that a backup has failed, don't ignore it.

2. Keep your software up to date. In the App Store or Software Update preference pane (depending on the OS version), you can configure automatic notifications of updates to OS X and other Mac App Store products. Some third-party applications from other sources have a similar feature, if you don’t mind letting them phone home. Otherwise you have to check yourself on a regular basis.

Keeping up to date is especially important for complex software that modifies the operating system, such as device drivers. Before installing any Apple update, you must check that all such modifications that you use are compatible. Incompatibility with third-party software is by far the most common cause of trouble with system updates.

3. Don't install crapware, such as “themes,” "haxies," “add-ons,” “toolbars,” “enhancers," “optimizers,” “accelerators,” "boosters," “extenders,” “cleaners,” "doctors," "tune-ups," “defragmenters,” “firewalls,” "barriers," “guardians,” “defenders,” “protectors,” most “plugins,” commercial "virus scanners,” "disk tools," or "utilities." With very few exceptions, such stuff is useless or worse than useless. Above all, avoid any software that purports to change the look and feel of the user interface.

It's not much of an exaggeration to say that the whole "utility" software industry for the Mac is a fraud on consumers. The most extreme examples are the "CleanMyMac" and “MacKeeper” scams.

As a rule, the only software you should install is that which directly enables you to do the things you use a computer for, and doesn't change the way other software works.

Safari extensions, and perhaps the equivalent for other web browsers, are a partial exception to the above rule. Most are safe, and they're easy to get rid of if they don't work. Some may cause the browser to crash or otherwise malfunction.  Some are malicious. Use with caution, and install only well-known extensions from relatively trustworthy sources, such as the Safari Extensions Gallery.

Never install any third-party software unless you know how to uninstall it. Otherwise you may create problems that are very hard to solve.

4. Don't install bad, conflicting, or unnecessary fonts. Whenever you install new fonts, use the validation feature of the built-in Font Book application to make sure the fonts aren't defective and don't conflict with each other or with others that you already have. See the built-in help and this support article for instructions. Deactivate or remove fonts that you don't really need to speed up application launching.

5. Beware of malware. Malware is malicious software that circulates on the Internet. This kind of attack on OS X used to be so rare that it was hardly a concern, but it's now increasingly common, and increasingly dangerous.

There is some built-in protection against downloading malware, but you can’t rely on it — the attackers are always at least one day ahead of the defense. You can’t rely on third-party protection either. What you can rely on is common-sense awareness — not paranoia, which only makes you more vulnerable.

Never install software from an untrustworthy or unknown source. If in doubt, do some research. Any website that prompts you to install a “codec” or “plugin” that comes from the same site, or an unknown site, is untrustworthy. Software with a corporate brand, such as Adobe Flash Player, must come directly from the developer's website. No intermediary is acceptable, and don’t trust links unless you know how to parse them. Any file that is automatically downloaded from the web, without your having requested it, should go straight into the Trash. A web page that tells you that your computer has a “virus,” or that anything else is wrong with it, is a scam.

In OS X 10.7.5 or later, downloaded applications and Installer packages that have not been digitally signed by a developer registered with Apple are blocked from loading by default. The block can be overridden, but think carefully before you do so.

Because of recurring security issues in Java, it’s best to disable it in your web browsers, if it’s installed. Few websites have Java content nowadays, so you won’t be missing much. This action is mandatory if you’re running any version of OS X older than 10.6.8 with the latest Java update. Note: Java has nothing to do with JavaScript, despite the similar names. Don't install Java unless you're sure you need it. Most people don't.

6. Don't fill up your boot volume. A common mistake is adding more and more large files to your home folder until you start to get warnings that you're out of space, which may be followed in short order by a boot failure. This is more prone to happen on the newer Macs that come with an internal SSD instead of the traditional hard drive. The drive can be very nearly full before you become aware of the problem.

While it's not true that you should or must keep any particular percentage of space free, you should monitor your storage use and make sure you're not in immediate danger of using it up. According to Apple documentation, you need at least 9 GB of free space on the startup volume for normal operation.

If storage space is running low, use a tool such as OmniDiskSweeper to explore the volume and find out what's taking up the most space. Move seldom-used large files to secondary storage.

7. Relax, don’t do it. Besides the above, no routine maintenance is necessary or beneficial for the vast majority of users; specifically not “cleaning caches,” “zapping the PRAM,” "resetting the SMC," “rebuilding the directory,” "defragmenting the drive," “running periodic scripts,” “dumping logs,” "deleting temp files," “scanning for viruses,” "purging memory," "checking for bad blocks," "testing the hardware," or “repairing permissions.” Such measures are either completely pointless or are useful only for solving problems, not for prevention.

To use a Mac effectively, you have to free yourself from the Windows mindset that every computer needs regular downtime maintenance such as "defragging" and "registry cleaning." Those concepts do not apply to the Mac platform. A computing device should not be a focus of your attention. It should be an almost invisible tool by means of which you communicate, work, and play. If you want a machine that is always whining for your attention like a neurotic dog, use a PC.

The very height of futility is running an expensive third-party application called “Disk Warrior” when nothing is wrong, or even when something is wrong and you have backups, which you must have. Disk Warrior is a data-salvage tool, not a maintenance tool, and you will never need it if your backups are adequate. Don’t waste money on it or anything like it.

hotwheels 22 wrote:

 

i am on Mountain Lion on the desktop and Mavericks on the laptop and my brain is telling me that i should do a Disk Defragmentation which is a PC operation.

Retrain your brain. Mac ≠ PC.

you have been around for tooo long to be asking!

TTPro etc, no.

Lean mean clean performs better when nothing is altering behavior or even monitoring system, I/Os, etc.

CLONE.

I do reformat drives and t hen clone and use the clone as the new system, pull and treat the old drive as backup.

One reason has been changes to partitions made as OS X grew up, partition tables change, what was reserved, and what was optional become mandatory. Plus I tend to buy new drives or SSD. And I always format a drive when a new OS comes out rather than throw a new OS on top.

Free space can get fragmented though it only becomes an issue beyond where you shoudl be filling a drive to begin with (and I do aim for 50% on boot drives, and 65% at most on media drives)

There seems to be happenstance that the folks that ask for help tend to have been using something to "make things better."

The boot drive should be internal normally, but you don't have to move a drive to have it be the boot drive.

Working system

Clone of working system

Clone of last OS X update (say 10.9.1) while you use and test 10.9.2

Clone of Moutain Lion 10.8.5 while you test and use 10.9.x and find if all your apps are ready for Mavericks.

Due to some kind of issue with Disk Utility's GUI ability to format 4TB and 3TB drives internally, it would also be nice to have 10.8.3 or earlier.

how you do that is of little to no concern. Only that you do it somehow.

and OS X can be tiny 20GB or it would be rather large and 300GB in rarer situations.

Small enough to carve out a tiny partition or even to use a sparse disk image you can restore if necessary.

To me it is just a spin on the old "grab a tape, slap it on and download tape to disk."

And while cloning back, you can have CCC do a file integrity check or another program.

And for me, a new OS is an excuse and use to be every 2 yr cycle that it was time to get a new drive for the system.

Right now 250GB SSD Samsung 840 goes for $144 so I just picked up a couple. Great system boot drives.

And when you restore (CCC or SuperDuper) all the free space is consolidated back.

Anyone that has tried to use Boot Camp Assistant and Windows very well may have run into the "I have tons of free space but it says it can't and to backup and restore" 1000s of threads from 2007 to 2012-3 when I stopped even reading or commenting, but... people had drives wtih 100GB of free space but all of it was in chunks, it was not contiguous, and often it was bound by unmoveable or locked or other files that prevent being moved easily.

Shrinking the HFS partition as much as possible (not safe to do btw without backups) might be able to move files and free space so that Windows could have its 80GB out of that 100GB (but 20GB might be 'more than 9GB" but it really is not a safe or good idea).  And no it was not Windows mnd set, it was, you can't use a Mac to install Windows unless the partitions are correct.

10% was what MicroMatTech and MacFixit got into the habit of rule of thumb while 18% and seeks and finding where to write and having files scattered over a drive affected performance.

Backup. Backup. Backup. A tape for weekend backups. A tape for monthly backups. A tape for Monday-Tues-Wed       adn then use Monday's for Thursday, and Tuesday for Friday, and Wednesday for weekend...

Not safe but for testing it worked to have one drive with 5 partitions and I would restore one of those (to keep it as is and unchanged) and restore it to my small SCSI 15K boot drive (which today is a small high performance SSD, names change but the players are the same).