I've created this site because so many Macintosh users
have expressed frustration that they don't know how to perform routine
maintenance on their Macintosh computer. Unfortunately, there
is a huge amount of misinformation going around on the
subject. Even Apple has contributed to the confusion with conflicting
tech notes on their Web site. With the assistance of a few, mostly free
utility programs, routine maintenance under OS X is very easy. The
problem for most users is figuring out which utilities to use, and how and when to use them. This
site will tell you that.
Just a little routine maintenance can make a Macintosh that is
acting old and slow run like it was new again! It can also banish
vexing spinning beachball cursors, rid you of "out of memory" error
messages, and keep your valuable data from being lost.
The Philosophy behind this site:
This is not (necessarily) a site for experts and power-users.
What I recommend here is what I see as the easiest, quickest, surest,
least intimidating, and least expensive way to accomplish valuable
routine maintenance. If you enjoy inputting arcane commands at a UNIX
prompt, if you know UNIX inside and out, if you have money burning a
hole in your pocket for commercial software with lots of questionable
features, or if you enjoy playing around with the features of powerful
(and potentially dangerous) software that you don't really understand,
this site isn't meant for you. I freely admit that there are other ways
to do the routine maintenance suggested on this site, but the
procedures that I recommend here are designed to be the best ones for
the average Macintosh user.
I've tried to make it easy as possible. I tell you what you
should do, and what you should do it with, and roughly how often. If
you are an average user, you can just follow my recommendations and be
happy that you have done what is necessary. If you want to know
more...the "why," or the other options, or any controversy that exists
in the Macintosh community over the need for these procedures, I've
provided a "Discussion"
section for each bit of routine maintenance, as well as a bunch of
There are several very common myths circulating about
Macintosh maintenance. I don't know anywhere else where they are all
acknowledged in one place. I have endeavored to mention them all on
this site. Look for the headings: "Maintenance
that one might experience while running OS X, especially performance
and memory error problems, can be traced to not having enough RAM
(memory) installed. The amount of RAM that comes standard with a new
Macintosh (assuming that you haven't paid to have more RAM installed at
the time of purchase) is usually the bare minimum necessary, and adding
more RAM to your Mac is usually a good idea. In my opinion, a Mac
running a recent
version of OS X (OS X 10.9 or later) runs best if it has at least 8GB
of RAM installed. More
RAM is better, though there are often diminishing returns above 8GB.
8GB is usually plenty for most purposes. (Note that some
older Macintosh models may max out at 4GB of RAM and cannot be upgraded
beyond that. 4GB of RAM will work fine, but is not ideal.)
If you want to find out if you need more RAM, this free
utility works nicely if you are running OS X 10.6 or earlier:
"Do I Need More Memory?"
(As of the date of this writing, "Do
I Need More Memory" is no longer supported by its
developer, but it still works perfectly if you are running OS X 10.6 or earlier.)
If you are running OS X 10.9 (Mavericks) or later, Apple provides a utility that does much the same thing. Open Activity Monitor
(in your Applications/Utilities folder) and click the “Memory” button
on the top. A window at the bottom will tell you how much swap or
virtual memory is being used. If it is zero or close to zero and stays
that way as you work on your Macintosh through the day, then you don't
need more memory. Also while in Activity Monitor,
there is a graph on the bottom of the window. It is called “Memory Pressure.” This shows a history of how much memory (RAM) is being used
and if you are overloading your memory it will go up and change color
from the normal green.
This Web page doesn't cover troubleshooting hardware problems. For
instance, many, maybe even most kernel panics (i.e. system crashes)
under OS X, are caused by hardware problems such as bad RAM,
problematic USB hubs, incompatible PCI cards, etc.
When using any software utility that makes changes to your hard drive's
system or structure,
there is always the slim possibility that things can go horribly wrong.
So, it is always a really good idea to have an up to date backup of all
of your important data before using any software utility.
Actually, it's just simply a good idea to always keep a backup of your
data in any case, because hard drives are notorious for failing when
you would least expect them to and you can least afford them to. For
backup software, I suggest that you check out:
and that you purchase an external hard drive to backup to. At this time
I prefer and highly recommend Glyph external hard
If you are experiencing a problem with your Macintosh,
performing all of the suggested routine maintenance found on this page
will often fix the problem. If it doesn't fix the problem, and you are
still encountering problems with slowdowns and/or seeing the rotating
rainbow beachball, see:
Macintosh OS X Beachballs!
http://www.macattorney.com/rbb.htmlMacintosh OS X Slowdown Solutions
Return to Table Of
UPDATE: Disk Utility in OS
X 10.11 (El Capitan) and later still has "First Aid" which is the
equivalent of what used to be called "Repair Disk". https://support.apple.com/kb/PH22243?locale=en_US
Disk Utility no longer has the "Repair Permissions" feature, because it
is no longer necessary. Permissions are immutable in El Capitan.http://www.macobserver.com/tmo/article/os-x-el-capitans-deletion-of-repair-disk-permissions-could-impact-you
If you are running a version of OS X prior to version 10.11, slow operation and generally unusual
behavior are signs that may indicate that permissions need to be
repaired on your Macintosh's hard drive. To do so you can run Repair
Disk Permissions from within Disk
, located on your hard drive at: Applications/Utilities/Disk Utility
Note: There is no need to verify permissions before you repair
them. Unless you can read the report and understand what Disk Utility proposes to do,
there is little point in verifying first.
You should run Repair Disk Permissions regularly. Maybe once a
month, and every time after you have installed new
software. (Contrary to popular belief, it is not at
all necessary to run Repair Disk Permissions prior to installing new
software. Though doing so won’t hurt anything.)
Open Disk Utility,
and on the left side of the screen select your hard drive, then select
the First Aid tab on the right side and click on "Repair Disk
for further details.
Note: Some users are reporting that they run Repair
Permissions over and over again, and the same permissions are reported
as being incorrect, and they are not being repaired. You should know
that, in addition to reporting faulty permissions, until very recent
versions of OS X, running Repair Permissions in Disk Utility also gave you
advisory messages. For instance, it might report that it is using an
updated set of rules to determine if any permissions needs to be
repaired. These are not error reports and they will not change no
matter how many times you run Repair Permissions. Advisory messages do
not indicate that anything is wrong, and they can safely be ignored.
"We are using special permissions for the file or directory
New permissions are 33261"
"ACL found but not expected" or “Warning: SUID file” error
These messages can safely be ignored.
Note: Some users have noted that their permissions revert to
apparently incorrect settings every time that they restart their
Macintosh. Disk Utility/Repair
Disk will correct their permissions, but the next time that they
restart the permissions have been changed again. This has
been traced to the fact that these users are running security software
such as Intego’s Virus
Barrier. The security software is intentionally
modifying permissions to close off potential malicious exploits.
Note that in this case, it is neither necessary, or even
desirable, to repeatedly repair your permissions to “fix” this
Update: As of OS X 10.7 (Lion) there is a way to repair more permissions; those in your User home folder:
1. Restart Lion, and before you hear the chime, hold down the
Command and R keys.
2. You’ll be at the Repair Utilities screen. Click the
Utilities item in the Menu Bar, then click Terminal.
3. In the Terminal window, type “resetpassword” and hit Return.
4. The password reset utility window launches, but you’re not
going to reset the password. Instead, click on the icon for your Mac’s
hard drive at the top. From the dropdown below it, select the user
account for which you want to repair permissions.
5. At the bottom of the window, you’ll see an area labeled
Reset Home Directory Permissions and ACLs. Click the Reset button there.
The reset process takes just a couple of minutes. When it’s
done, close everything and restart your Mac.
#1: "You need to repair permissions from a copy of Disk Utility that resides on
the drive that you are repairing."
This is a myth that is very prevalent.
It used to be that you were warned against repairing
permissions on one disk while booted from another because only the
receipt files on the drive you were booted from would be consulted, not
the receipt files on the drive you were repairing, and thus not all
permissions would be set correctly. This is no longer necessary. As of
late in OS X 10.2, you could run Repair Permissions while booted from a
disk other than the one that you are repairing (e.g. the OS X installer
CD-ROM), and it will correctly use the receipts on the disk being
#2: There are some folks who are very adamant that you
never need to repair permissions under OS X. While repairing
permissions isn't a panacea, they are wrong, it is definitely worth
your while to repair permissions occasionally. The reality is that
Repairing Permissions doesn't require that you purchase anything to do
it, it can be accomplished fairly quickly, it doesn't hurt anything,
and after repairing permissions sometimes the problem(s) that the user
is experiencing are gone. In addition, often the curative effects of
repairing permissions are repeatable and predictable. I don't see any
reason not to do it.
Apple provides a list of reasons that you may need to repair
Here is a (rather extreme) example of the "it's never ever
necessary" school of thought:
Exercises in Futility Part 2: Repairing Permissions is Useless
From the folks at MacFixIt, who recommend routine repair of
Another follow-up to the Repair Permissions debate
The MacFixIt article makes this excellent point: While Disk Utility's Repair
Permissions feature only repairs permissions for Apple Software (and
not any third party software), much of that Apple software is system
software, and that system software contains routines that are accessed
and used (and used often) by third-party applications. Thus,
incorrectly set permissions, contrary to what some would tell you, can
cause problems with third-party applications.
These MacFixIt articles further explain what repairing
permissions does, and they document real-world cases where repairing
permissions was extremely helpful to users.:
Unraveling the Repair Disk Permissions controversy
Repair Permissions Success Stories
More Repair Permissions Success Stories
Frequently Asked Questions On Fixing Permissions In OS X
Microsoft Office, and especially Microsoft Word, often
requires, and responds very well to repairing permissions:
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REPAIR DISK PERMISSIONS
RUN ROUTINE MAINTENANCE SCRIPTS
OS X runs its own built-in
maintenance routines, sometimes called "cron jobs", or "maintenance
scripts", automatically between 3:00 am and 5:30 am each day. (There
are daily, weekly and monthly scripts).
The thing is that these scripts do just about nothing of great
importance. If they don't run for weeks, or even months, it's
just not a big deal. So, despite the fact that these are
called "maintenance routines," don't get concerned if they haven't run
in a long time. Don't ignore this entirely, though, because
if your Mac has a minor problem, in time failure to run the maintenance
scripts will allow your Mac's hard drive to fill up with a bunch of
invisible log files filled will message about that minor problem.
You can find a rundown of what the built-in maintenance routines do at:
Prior to OS X 10.5, if you didn't leave your computer on 24 hours a
day, or if you left it on but you let it go into sleep mode at night,
these routines weren't run. As of OS X 10.5 and
later your Mac will run its maintenance scripts automatically at the
next available opportunity if you put your Mac into sleep mode all
the scripts still won't run if you shut your Macintosh down at night.
NOTE: As of OS X 10.5 the maintenance scripts are no longer
handled by the UNIX facility "cron", they are now handled by a similar
facility called "launchd," if that means anything to you.
you decide that you want to run the maintenance scripts manually, you
can use this free utility:Maintidget
(Maintenance Scripts Widget)http://www.giantmike.com/widgets/Maintidget.html
If you want to be sure that the built-in maintenance tasks have been
run, the daily, weekly and monthly maintenance scripts each write the
details of every run into their own log file, which you can check. Open
application (located at: Applications/Utilities/Console), go to:
File --> Open Quickly --> /var/logs/. Select "daily.out",
"weekly.out" or "monthly.out" for the maintenance logs.
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Even though running the routine
maintenance scripts clears out some temporary files, none of the system
caches are touched by them. Occasionally caches become corrupted,
impacting the performance and stability of your Mac. So it is
a good idea to every rare now and then use a utility that clears the
system caches, and/or your Internet browser caches. Deleting caches
won't hurt anything. However, over time a cache speeds up your computer
(assuming that you do some things repetitively), so if you aren't
experiencing any problems, you should probably leave your caches alone. On
the other hand, if it has been ages since you have flushed your caches,
or if your computer is running slowly, or if you are experiencing odd
problems, it might be a good idea to flush them. Use your discretion.
(In other words, this isn't something that you should be doing
every day, or every week, or even every month.)
YASU is a
free program which, among other useful things, cleans out system and
Internet browser caches. You can get YASU from:
caches are easily uninstalled or trashed manually, but should probably
be limited to instances where an individual application is running
slowly or erratically:
that Booting into Safe Disk mode automatically clears the Apple ATS
(Apple Typographic System) font caches. However it doesn't clean out
other kinds of caches.
According to MacAddict, October 2005, page 20, it is a good
idea to occasionally clear out application-specific caches. They
specifically recommend clearing out the two main cache folders in Mac
While Apple doesn't recommend doing this routinely, they indicate that
it is a good idea in certain situations:
A MacOSXHints tip also suggests clearing out the application
cache files occasionally:
This hint notes that there may be quite a few extraneous cache
files in your cache folders and that clearing your caches (if you have
been using your computer for some time) may save a lot of disk space.
Return to Table Of
DO A FILE SYSTEM CHECK AND REPAIR DISK
I recommend that you occasionally
restart your Mac, and hold down the Shift key right after the startup
chime is played, and keep it held down until the spinning black bar
cursor appears. There is no need to hold down the
Shift key past the time that the spinning bar cursor appears.
This procedure invokes what Apple calls a "Safe Boot":
and your Mac will report that it has been booted (started up) into Safe
Boot mode. During startup in Safe Boot mode your Mac will do a file
system check, entirely in the background, with no working status
indicated, or report generated, and any problems will automatically be
It may take a while for your Mac to start up in Safe Boot mode. Be
Patient. Once it has fully started up, you should immediately
restart your Mac normally, because certain files are deactivated when
you startup in Safe Boot mode.
wireless or Bluetooth keyboard might make it difficult to startup in
Safe Boot mode.
Update: Some recent models of Mac seem to have depreciated Safe Mode and/or won't let you boot into it.
Apple indicates that there still is a Safe Boot mode in Yosemite:
but some users report not being able to startup into Safe Boot mode in Yosemite.
Instead you may prefer (or need) to check your hard drive, and repair
any problems, by starting up in "Recovery mode" (by holding down Command-R during startup) and then running Disk
Longtime Macintosh users know that under OS 8 and OS 9, if you
were experiencing nasty problems with your hard drive, that running
Apple's Disk First Aid
usually didn't fix them. In such cases, users often resorted to using
the commercial product Disk
Warrior, which could perform near miraculous feats of
repair on your hard drive. It was also an invaluable tool for routine
preventative maintenance. Under OS X, Disk Utility/Repair Disk
is the replacement for Disk First
Aid. So, the question most folks have is, 'is Disk
Utility/Repair Disk as lame as Disk First Aid, and is Disk Warrior still an
invaluable utility to have?' There is an interesting thread on TidBits
Talk that covers this topic:
Looking for Disk Warrior
The answer is that Disk
Warrior is a marvelous tool...when you need it.
Fortunately, under OS X you just about never need it. For instance, you don't need to
run Disk Warrior
routinely as a preventative measure. (Though doing so, if you already
own Disk Warrior,
isn't a bad idea.) OS X is plenty stable without having to constantly
rebuild its directory. And so, in my opinion, there is no need to
purchase Disk Warrior
(for about $100) unless a situation arises where Disk Utility/Repair Disk
reports that it can't repair a problem with your hard drive. This is
not to demean Disk
Warrior. When you do need Disk Warrior,
because your disk directory has developed errors that Disk Utility can't fix, it is
a godsend to have.
For further information about disk repair software, have a
with a follow-up on TechTool Pro at:
There are other ways to run a file system check/Repair Disk
under OS X, such as by running the command "fsck" from the Terminal,
but these are more advanced ways to do exactly the same thing, that I
don't think that the average user needs to know about.
Return to Table Of Contents
For more information than you need, see:
DEFRAGMENT A HARD DRIVE THAT IS LOW ON CONTIGUOUS FREE SPACE
: Most folks with an opinion will probably tell you
that Mac's running OS X never need to have their hard drives
Here is a quote from a MicroMat technician, that I think is
"The claim that installations of Mac OS X on HFS+ volumes do not
fragment is a myth believed by people who do not have disk optimizers
that allow them to see how much fragmentation their disks have. It is
an example of ignorance that is not able to be removed by any amount of
evidence. I think theologians call that 'invincible ignorance'. It is
now a widespread form of the pollution of information space."
Macs running OS X can benefit quite a bit from defragmenting their hard
drive. But not for the reason that you might expect. There is often
little in the way of performance to be gained by defragmenting your
hard drive. But defragmenting your drive can stave off some very flaky
behavior, out of memory errors, and possibly even data loss.
OS X handles "file" fragmentation (a file being broken up into
chunks and strewn across your hard disk) automatically, and fairly
well, every time that you launch a fragmented file under 20MB.
But OS X doesn't handle "drive" fragmentation (small
bits of free space between files) well at all. In fact, OS X is prone
to huge amounts of drive fragmentation.
Drive (as opposed to file) fragmentation under OS X is mostly
irrelevant with respect to performance, as long as it isn't severe.
Where drive fragmentation becomes important is when there are no
longer any large contiguous chunks of free space left on your drive for
OS X to use for working space, for virtual memory, temp files,
databases, etc. When this happens, OS X can start acting flaky, and
eventually, in extreme cases, it will suffer from data loss.
I used to recommend that folks defragment their hard drive
when it was approaching 80% full (no matter how large the drive is),
because I've heard from so many folks who were experiencing
out-of-memory errors and flaky behavior at this level (no matter how
large their drive was), and defragmenting invariably fixes the problem.
But I've heard from a number of users who made heavy use of their
drive, and they have experienced the problem as early as around 60%
full. And other folks won't experience the problem until their drive is
well over 80% full. Clearly how you use your drive makes a difference
as to when, or if you run out of free contiguous space on your hard
So now, instead of using a rough rule of thumb on when you
should consider defragmenting your hard drive, what I recommend is that
folks check to see how much free contiguous space there is on their drive
routinely, once their drive is over 50% full. You can do this quickly
and easily with the free demo version of iDefrag:
There is no need to
purchase anything until and unless you need to. When you
have no large chunks of free contiguous space left, you can expect
problems to begin to appear if you don't defragment your drive. Note
that if you let this problem advance too far, it may become impossible for any
utility to work on your drive, protesting that there isn't enough free
space on your drive for it to be able to run. (This despite the fact
that you may have many gigabytes of "total" free space left on your
You may never need to
defragment your drive (prior to purchasing a new one
because the old one is becoming too full) or you may need to do so much
earlier than you would expect, but by checking with one of these free
tools you won't have to guess whether it is necessary or not.
If your drive needs to be defragmented, the "only" hard drive
defragmentation utility that I recommend is iDefrag.
(See my comments about other hard drive defragmentation utilities in Note 1. below) It is the only one
that I know of that can optimize the files on your hard drive in a
totally OS X-savvy way. OS X has a journal, a
hot band, virtual memory, metadata, etc. to keep track of. It is very
important that these things be located properly on the disk or
performance will be compromised.
Technical data about the hot band and meta data on hard drives running
OS X 10.4 and later:
the only hard drive optimization tool that does this perfectly (despite
what some of the other companies that make hard drive defragmentation
Another option, instead of defragmenting your hard drive with
a software utility program, is to simply purchase a new, bigger hard
drive; copy all of the data on the old drive to the new drive, and then
reinitialize (i.e. wipe clean) the old drive and start over with it.
Moving all of your data from one drive to another will automatically
defragment your data. Though
it won't optimize it.
You have to reinitialize your data on the old drive for this
plan to work, because if you just move "some" data from your old drive
to your new drive, the old drive will still be badly fragmented, and
without defragmenting the old drive it will still probably be flaky.
(That is, even if you free up some space on the old drive, there more
than likely still won't be the large chunk of contiguous free space
available that the OS needs to run properly.)
Defragmenting your hard drive prevents any unusual behavior
from your OS because it creates contiguous space, combining fragments
of space strewn all over your drive into one large chunk of space.
Note that clearing off data from your drive, even a large
amount of data, without also defragmenting, may not create enough
"contiguous" space to keep your Mac running well.
You should never,
ever, defragment a solid state hard drive (SSD) (Most recent Macbook's use SSD's
for their speed and light weight. Several other Mac models,
including recent desktop models, occasionally have SSD's for their speed.) or a hybrid drive
(hybrid drives are sort of a combination of an SSD and a rotating disk
SSD's themselves need no periodic maintenance. There
is built-in software in recent versions of OS X called TRIM that keeps
them running at peak performance:
Definition of Terms:
Types of fragmentation:
1) "File fragmentation,
where file are broken up and are not contiguous
2) "Drive" fragmentation,
where, though files may be contiguous, the free space on the drive is
means that things (that is, data, e.g. files and applications, and free
space) are made contiguous (that is, not broken up into small bits and
strewn about at different places) on your hard drive.
means that not only is the drive defragmented, but data is put where it
should be and.or is put where it will provide optimum performance.
Let's refer to files A, B, C and D, and free space "__".
Here is a drive with no file fragmentation. All the files are
contiguous, but free space is fragmented. In other words, there is no
file fragmentation but there is disk fragmentation:
Here is a drive with both the files and free space fragmented:
Here is a drive with no file or free space (disk)
fragmentation. All of the files are contiguous, and all of the free
space is contiguous:
Now, take a look at that first example, where there is a lot
of disk fragmentation even all of the files are contiguous. Have you
ever run a Mac under OS X with too little RAM? It was a dog, wasn't it?
That's because your Mac was hitting your disk in a big way, using
virtual memory instead of RAM for tasks. Now, think of the effect that
you might see if you forced your Mac to use hundreds of little spaces
all over your drive to write virtual memory to, instead of having it
written to one big contiguous space. That's why drive fragmentation is
more important than file fragmentation.
OS X automatically defragments files. OS X doesn't do any
drive defragmentation at all.
Note that if you actually defragment your hard drive as part
of a routine maintenance program (rather than just keep track of how
much free contiguous space is available), let's say every coupe of
months, then it won't take long to defragment your drive each time, and
any potential problem will never rear its head. In addition, you should
be able to use close to every last gigabyte of space on your hard
drive, and you will always have every last ounce of performance that
your Mac can give you as as side benefit.
See Note #1 below for
more information on file defragmentation.
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CHECK S.M.A.R.T. STATUS
Hard drives are quite a bit more
reliable these days than they were just a few years ago. Unfortunately,
the old saying that "all hard drives die eventually" is still true. It
would be nice to know in advance when a hard drive is going to fail.
That way you would have time to backup your data before your drive
ultimately met its end. S.M.A.R.T. (Self-Monitoring Analysis and
Reporting Technology) is a feature built into most modern hard-drives
that acts as an "early warning system" for pending drive problems. OS X
10.3 and above have this ability built-in, but it only works if the
actual hard drive in your Mac has this technology built-in also. Disk Utility
, which comes
with OS X (it is in your Application/Utilities folder), under OS X 10.3
and above can tell you the S.M.A.R.T.-status of your hard-drive.
Unfortunately, you have to remember to regularly launch Disk Utility
to check this.
(See below for free utilities that will automate this process.)
To check your drive's S.M.A.R.T.-status using Disk
Utility, launch Disk
Utility and select your internal hard drive in the left column. If at the bottom of
the window it says "Verified," your drive is in good shape. If it says:
"About To Fail" you need to:
1) Not shut down your computer and hard drive until you have done the
2) Back up your hard drive, which you should do immediately, if you
haven't already done so.
Hard drives on their last legs often will finally fail by refusing to
I've been told that there is no hope for an internal drive
once it reports "Failing" as its S.M.A.R.T status. Its time to get a
Volitans' SMART Utility
($20 for a 10 copy license) is different from other similar utilities
which only read the overall S.M.A.R.T. Status. SMART Utility goes farther
and displays the individual attributes tracked by S.M.A.R.T in an easy
to read format so that you can see their status and information, and it
also uses its own internal algorithm based on those attributes to
detect drives failing before S.M.A.R.T. normally would. This pre-fail
detection can save your data well before S.M.A.R.T. has determined that
the drive is failing.
Note: FireWire and USB hard drives (that is, external hard
drives), even if their internal mechanism is S.M.A.R.T.-enabled, can't
be checked for S.M.A.R.T. status using Apple's Disk Utility. However, you might be able to check the S.M.A.R.T. status of your external hard drive by downloading the demo of SMART Utility:
After installing SMART Utility
you will need to install the optional SAT SMART Driver (from the
SMART Utility menu) in order to see any external drives. That will
tell you your external drive's current S.M.A.R.T. status, as well as
monitor to see if any new problems crop up. Another option, for those who are much more advanced is:
There was a study released by Google:
Return to Table Of Contents
Failure Trends in a Large Disk
which concluded that S.M.A.R.T. wasn't a
reliable predictor of drive failure. (Note: Anecdotal feedback
from users to this Web site's author indicates that Volitan's SMART Utility's proprietary algorithm does give a reliable prediction of hard drive failure.)
More information on S.M.A.R.T. technology:
CLEAR YOUR DESKTOP
8) RESET SAFARI
Moving things to a location other
than on your desktop is an easy and free way to pick up better
performance. Users have noticed that reducing the number of items on
their Mac’s desktop can noticeably increase the performance of certain
activities in OS X. This is easy to do. You can even create one folder
on your desktop and put everything on your desktop in it. That will do
the trick. Nested items within folders on the Desktop don't count. It
is only the total number of items directly on your desktop that matter.
Another way to go is to put all of the items that would
normally reside on your desktop, that you want to be able to access
quickly, in a folder; park that folder somewhere other than on your
desktop, and then drag that folder to your Dock so that it is always
available from the Dock. Whenever you click and hold (or Control-click,
or right-click on a two button mouse) on that folder in the Dock, you
will be presented with a menu of everything in that folder to choose
from. Sort of like the old classic Apple Menu.
Things that you put on your desktop don't really reside there.
They actually reside in a folder in your user account. The Desktop
folder can be found at:
[hard drive icon]/Users/[your user name]/Desktop
otherwise known as: ~/Desktop, or your "user desktop folder".
Open this folder and you will find everything that you see on your
desktop! Making the stuff that appears in this folder appear on
your desktop is resource intensive, and the more things in this folder,
the more resources are impacted.
Update: The need to
clear your destop has become controversial. Some folks claim that
Apple has completely changed the way that things are represented on
your desktop and that it no longer matters how many items are on your
desktop. Others say that they still see a slowdown from having too many
items on their desktop, and that clearing their desktop resolves the
problem. it's hard to tell which is the truth, because no
one has explained what the changes are, exactly, and Apple has no
technical briefs saying that a change was made. From anecdotal
evidence, I think that the situation is somewhere inbetween. I
think that there is still some overhead required to put all of the
icons on your destop, but that the performance hit isn't nearly what it
Fortunately, you can quickly and easily prove or
disprove this for yourself. If your desktop is full of icons,
drag everything into a folder and see if performance increases
afterwards. If it doesn't, you can simply drag everything out of
the folder and back onto the desktop.
Return to Table Of Contents
of OS X 10.10 (Yosemite), Safari no longer has a reset function.
In an extreme case, have a look at this article for how to reset
Here is a trick to keep Safari running like a top:
Occasionally delete the QuickTime plug-in preferences file:
Close all browsers.
While in the Finder, Option-click the Go menu
Your ~/Library (user library) will appear in the menu; choose it
Go into the Preferences folder
and delete this file (it will be rebuilt the next time that you launch your Web browser):com.apple.quicktime.plugin.preferences.plist
Return to Table Of Contents
9) UPDATE FLASH AND DELETE FLASH COOKIES
The first thing that you should do if
you have a stability or speed problem with your Web browser is
update Flash Player. It almost always helps.
Uninstall the copy of Flash Player that you have installed with this
uninstaller (Adobe recommends doing this first):
Then download the latest version of Flash Player directly from Adobe, and
When you are done doing that, if you haven't done this previously, this will really help your browser's performance:
Delete all of your Flash cookies. (Note: This cannot be accomplished using
Safari's Security settings. While they can deal with ordinary cookies, they don't effect Flash cookies).
In addition to the regular cookies that most users know about (and
which are perfectly safe and legitimate, despite the mythology surrounding them), there are Flash cookies,
which are rarely legitimate. Most web browser's built-in
security features don't block and can't purge Flash cookies.
When these cookies accumulate (and they do so very quickly), your Web
browser will slow down. They are easy to get rid of,
and at the same time you can make sure that they can't be
downloaded to your Macintosh ever again.
into System Preferences --> Flash Player --> Storage --> click
on the "Delete All" button --> enable "Block All Sites From
Storing Information On This Computer"
The only thing that
I've ever encountered that is negatively impacted by deleting and blocking Flash cookies is Pandora,
which will still work, but it won't save your user created "channels."
You can set Flash Player to create an exception for Pandora (or
any other applications that you approve), but personally I just
switched to Spotify instead, which doesn't use Flash cookies.
Return to Table Of
10) REBUILD MAIL’S DATABASE AND BACK UP YOUR
Ever since OS X 10.4, all archived
messages in Apple’s Mail program have been kept in individual
Finder-readable files. There are no archived messages in Mail's
This is a good thing. Some other e-mail programs,
notably Microsoft’s Entourage, store all of your messages in one big
monolithic database. If the database in a program with a
monolithic database becomes corrupted and unrepairable, you can lose
all of your archived mail.
works by storing information such as senders, recipients, subjects,
etc. in a SQLite database. Mail’s performance can lag, and it can
stable, as you store more and more archived messages in it.
Periodically deleting old, unwanted e-mail messages, and
rebuilding Mail’s database, will usually give Mail a very noticeable
performance boost, and help ensure continued trouble-free operation.
Since there are no archived e-mail messages stored in Mail’s
database, it is quite safe to rebuild Mail’s database, because if
something goes wrong with the rebuild, you can just start over, having
Every now and then (or, ideally, routinely as you use Mail)
you should go through all of your mailboxes in Mail and delete all of
the messages you no longer wish to keep. Then, in Mail, choose:
Mailbox menu --> Erase Deleted Messages --> In All
to purge all deleted messages.
After doing this, quit Mail.
Now you are going to rebuild Mail's envelope database. You can
do this manually, via a script, or using the Terminal (your choice,
based on how advanced a user you are):
As of OS X 10.11 (El Capitan), Apple changed where Mail stores
its archived e-mail files. To rebuild the Mail database, do this:
Go to your user Library folder by holding down the Option key in the Finder, and then choosing: Go menu --> Library
In ~/Library/Mail/V3/MailData, move any file that begins with “Envelope Index” to your desktop, such as:
Mail and fresh new Envelope Index files will be created. This can
take a while if there are a lot of archived e-mail messages to go
If the above doesn't help, delete any file with the
name “index” in it from the folder in ~/Library/Mail/V2/MailData. This
is the old location where Mail stores mail indexes in OS X 10.7 through
10.10. Any left over files may be conflicting with OS X 10.11 El
Return to Table Of
Note #1) More On Defragmenting
Your Hard Drive
As I indicated above, there are those who will tell you that
you *never* need to defragment your hard drive, and to some extent they
are correct. Certainly the average user, with a hard drive that isn't
anywhere close to being full, and using applications that don't require
every last bit of performance that can be mustered, won't notice any
significant performance gain, or other benefit, from defragmenting
their hard drive. (Though you may find defragmenting your hard drive to
be important if you do disk-intensive work, such as video editing.)
Just about all of the experts agree that there is a Macintosh
problem that manifests itself when your Macintosh gets somewhere around
80% full. However, not all of these experts seem to realize that the
problem is due to a lack of free contiguous space on your hard drive.
As a result, these folks usually advise that you deal with this whole
problem by purchasing a new drive when your old drive gets to be about
80% full. That will work, but, personally, when I have a 200GB drive,
with 40GB unused, I expect to be able to use that 40GB before I have to
buy a new drive. 40GB is a huge amount of space and it seems silly to
just give up on it. Frankly, it seems to me that advising that one
always keep a ridiculously large amount of free space available on
their drive, to assure reliable operation, isn't the best course.
See under: "Make sure you have enough free space on your startup volume"
Realistically, 20 percent of your Mac OS X startup volume should be
kept clear in order to achieve best performance and avoid disk problems.
Rob Griffiths, of MacOSXHints.com and Macworld magazine writes:
Keeping at least 10% of your drive space free is advice that I've
followed for quite a few years; I don't know if that figure is too high
or too low, but I've never run into any drive-space-related issues
using it as a benchmark.
"...keep at least 15% of your startup drive free at all times; more is better."
Joe Kissell of Macworld
magazine recommends defragmenting your hard drive as it starts becoming
too full or when there is severe disk fragmentation.
February 2008, page 102.
If a UNIX system employs non VM for memory
management (that is, real memory) the issue of swapping is a different
beast altogether. This is because when swapping memory out it has to be
done in large contiguous chunks (not small pages of 4096 bytes). For
this reason it's important that the swap file space on disk be a
contiguous set of tracks/cylinders and if possible have a separate data
path to avoid interfering with other user i/o activities.
Apple says that you generally don't need to defragment your
hard drive if you are running OS X 10.2 or higher:
But then they say: If your disks are almost full, and you often modify
or create large files (such as editing video...), there's a chance the
disks could be fragmented. In this case, you might benefit from
defragmentation, which can be performed with some third-party disk
Here they say that in some instances defragmenting your hard drive may
So, Apple seems to be saying that you don’t need to defragment your
hard drive...except in those instances where you need to defragment
your hard drive.
Apple adheres to the "leave a ridiculously large amount of
free space on your drive and then replace your drive when it
prematurely begins to hit its head" concept. They admit that
defragmenting your hard drive is a good idea, but they will only admit
it for those who badly need to do it. (Folks who really give their
drives a workout, and those who edit video.) For everyone else they
feel that its just fine for them to purchase a new hard drive when they
encounter a problem with a lack of free contiguous drive space. As
Apple says, modern hard drives are big. Apple knows that for many users
it will take a long time for them to fill their drive up to around 80%
full, if ever. They aren't about to recommend maintenance that isn't
necessary for everyone. In addition, Apple has always been reluctant to
admit to users that they might not be able to get along without some
third party utility. For instance, under OS 8 and OS 9 Disk Warrior was practically
a necessity. But you never heard Apple admit this.
According to one of their technicians, MicroMat feels that
under certain circumstances defragmenting your hard drive is very
important, and may even be critical to preventing data loss, and
based on my experience I concur:
Continuation of discussion on fragmentation by MicroMat tech:
MacFixIt has an article on defragmenting your hard drive,
including a test of iDefrag:
“...in our informal testing, we noticed significantly snappier
operation of Spotlight and quicker response from Mail.app after
performing only the least invasive of iDefrag's
“The bottom line is that users with large files will benefit most
greatly from defragmentation routines in Mac OS X. However, use of the
disk optimization routines offered by tools like iDefrag can also serve as a
boon to casual users of Mac OS X looking for a speed boost.”
ShirtPocket Software, makers of SuperDuper have a short "white paper"
about the need to defragment your hard drive:
Utilities...and Disk Warrior:
Some manufacturers use the terms "defragmentation" and
"optimization" interchangeably. For instance, as far as I can tell,
MicroMat does this even though TechTool
Pro doesn't really do any optimization when defragmenting
your hard drive.
Prosoft's Drive Genius
does both file and disk defragmentation, but as far as I can tell, no
optimization. However, their advertising seems to use the terms
"defragmentation" and "optimization" interchangeably.
Intech Speed Tool's
Guides/Disk Defrag Guide.pdf
says that the product defragments your drive, but it does not optimize
it. So it would appear that Intech's product is not an optimal choice.
sometimes refers to what Disk Warrior
their popular hard drive repair utility, does as "optimization" and/or
"defragmentation." However, they are referring to the drive's
directory, not to defragmentation and optimization of the drive’s files
(data) and free space on the drive. Many folks get confused by the
terminology used and think that Disk Warrior is a hard drive
defragmentation utility, and it is not. Your Macintosh maintains a
"directory" which is an invisible structure that is a catalog of all of
your Mac's files and system parts. (It is actually more complex than
this simple explanation.) If the directory becomes corrupted your Mac
can lose track of what is on your hard drive. (e.g. Your files
For a more detailed and technical explanation, see:http://alsoft.com/DiskWarrior/details.html
your Mac's directory by rebuilding a new optimal one from scratch.
Other utilities attempt to fix the directory by patching the directory
structure rather than by rebuilding it. Disk
also optimizes the structure of the directory for
maximum overall disk performance.
Return to Table Of
Note #2) Routine Maintenance Or
A couple of well-known Macintosh authors have been quoted as
saying that many of the procedures listed on this Web page, such as
Repairing Permissions, are not what they consider to be routine
maintenance, but rather they are best reserved to be used as
troubleshooting techniques when your Macintosh shows signs of decreased
performance or starts acting in an unusual manner. They say
that you can go a long time without having to perform any of the
procedures that I list here.
I can’t say that they are wrong. However, I compare
it to checking and adjusting the air in the tires of your car.
Do you do that regularly, or do you wait until your tires
start to show signs of unusual wear and/or your car starts to handle
poorly? Many people do the latter, and I can’t say that they
are wrong in doing so.
What if it took less than ten minutes to check and adjust the
air in your car’s tires, and you didn’t have to get your hands dirty,
or leave the comfort of your home to do so? Would you then be
more likely to check the air in your tires regularly, especially
considering the benefits of better handling, longer tire life, etc.?
It seems to me that it would be well worth your while to do
That is where my feelings are as far as the procedures on this
Web page. You can do them all quickly, easily, and at no
monetary cost, and there is no downside to doing them. But
the upside to doing routine maintenance is that your Macintosh will
always be running at its best (not just when you have noticed that
things are really out of wack, and you decide that its time to
troubleshoot and repair them), and you may even avoid some nasty
problems down the road. You can decide for yourself if the extremely
modest investment of time and effort is worthwhile to you.
Return to Table Of Contents
If you have any additions to this Web
site to suggest
I would very much appreciate hearing your suggestions.
Send them to:
Randy B. Singer
About The Author Of This Web Site
Randy B. Singer is:
- The head of the MacAttorney User Group
with, at this writing, well over 9,500 members!;
- A co-author of The
Macintosh Bible (4th, 5th and 6th editions);
- Author of the ABA publication:
The Macintosh Software Guide for the Law Office
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