Software and Computer Systems Company, LLC |
In this article, we will be describing software problems that
can exhibit symptoms similar to those associated with
problematic hard disk drives (HDDs) and solid state drives
(SSDs). The problems we will address may be operating system
bugs, applications or processes that present problems to a
system that may make the system act like it has a drive problem,
or applications, processes, or drivers that may be incompatible
with a system.
This page is one page in a series of five pages dealing with HDD
and SSD problems and their associated symptoms. If you haven't
read the main page of this article, we recommend clicking on the
link to the left titled "Article Main Page" before proceeding.
This article will focus solely on problems specific to software
problems, and it will not directly address any of the problems
that genuinely originate from a bad drive.
This article will address the list of symptoms that are defined
in the main page of this article associated with software
problems. Each of the following subsections will describe the
symptom, its possible causes, and how to correct it if possible.
For the sake of review and clarity, the symptoms we identified
in the main page of this article were in the classification
titled Operating system bugs or other software related
problems and are as follows:
Software itself can cause problems by using high levels of CPU
power, using large amounts of memory, or making excessive use of
the hard drive. Some of these are addressed in the "User
Problems" section associated with the link at the top of this
page. Aside from actual user installed software, the following
system applications may be responsible for problems:
The mds process was problematic
primarily in Mountain Lion (MacOS 10.8) and earlier versions of
the operating system. It can still be problematic on newer OS
releases, but it seems to occur mostly in bursts. The mds
process seems to have problems indexing certain types of files,
and if a lot of them exist on a system, it might cause the
system to bottleneck as it can be extremely drive and CPU
intensive. Additionally, if a user is using a system with
multiple boot partitions with multiple versions of OS X on it,
some the differing OS versions handle mds data
differently and may force a re-index of all drives on the system
subject to indexing. Indexing is used primarily by both Spotlight
and TIme Machine and some other applications.
Resolution:
First, find out if mds is actually the problem. This can be
done several ways:
Regardless of how you make the determination, if mds is
found to be the culprit, the following techniques may be taken
to minimize it:
Open up System Preferences, select the Spotlight
option, and in the Privacy tab, add all the disks,
volumes, or folders you don't want indexed to the list of
excluded items. This will limit indexing for Spotlight
but will not have any effect on Time Machine indexing if
it's used. If the system is a multi-boot system you will
need to ensure the indexing limitations are consistent across
all boot drives.
If you can do without Spotlight or Time Machine,
ensure that Time Machine is disabled and then add all
drives in the system to the excluded list for Spotlight
via System Preferences as described above.
If the system is new, a fresh install, or it hasn't been used in
a while, mds may initially start a full indexing
session, which may take hours, and then settle down after a
while. Once it's stabilized it may stop being problematic on its
own. If a system is being used with only one drive or perhaps a
drive an a backup drive, this should be worth a try.
If you're using a system that boots multiple partitions or
frequently has external drives connected and disconnected, you
may wish to try and control the indexing activity with SpotOff.
Information on SpotOff may be obtained HERE.
The Icon Services Agent is a process that
generates icons for every single user account on the system,
even if they're redundant. When processing icon information, it
can literally eat up gigabytes of data in a matter of minutes,
and continue doing so until it's complete. When highly active,
this process is CPU, memory, and drive intensive. The more
accounts there are on a system, the more files it will generate.
Icon Services Agent appeared in Mavericks (MacOS 10.9).
Resolution:
Generally this process will only be noticeably problematic during a new installation of the operating system and once in a rare while when using the system. Monitoring its activity may be done using Activity Monitor (provided with the operating system) or using Performance Probe (Performance Probe is included in the Scannerz package or may be obtained as a stand alone package. Information on Performance Probe may be obtained HERE). One negative side effect of this process is that the icon files can be several gigabytes in size and will grow with time. If the system is running low on drive space a user may need to start monitoring drive space more frequently to ensure a problem doesn't exist.
Safari Web Services and browser plugins
may be extremely CPU and memory intensive. In some cases it may
not really be the fault of the browser, but an abusively written
set of web pages that can have the effect of "summoning up"
several instances of these processes simultaneously. In most
cases, the problems will stop when the browser is completely
terminated.
Resolution:
This problem is typically web site specific and as stated is often the result of abusive sites. Monitoring system activity may be done using Activity Monitor (provided with the operating system) or using Performance Probe (Performance Probe is included in the Scannerz package or may be obtained as a stand alone package. Information on Performance Probe may be obtained HERE). Terminating web browsers completely should end the problem almost instantaneously
If a Time Machine backup is occurring unknown to the
user, it can be responsible for a performance drop and delays.
Versions of MacOS prior to Mavericks (10.9) had an icon that
could be installed in the menu bar, and when a backup was
occurring the icon would spin until the backup was complete,
which would allow a user to know a backup was occurring. With
Mavericks and later, the icon can still be placed in the menu
bar but it no longer spins during a backup, and if the backup
drive is out of sight or has no indicators to identify backup
activity, a backup may be occurring without a users
knowledge.
Resolution:
Be aware of Time Machine and if delays are occurring, see if it's performing a backup. For systems where it may be difficult to identify this activity it may be necessary to start monitoring system activity using Activity Monitor (provided with the operating system) or using Performance Probe (Performance Probe is included in the Scannerz package or may be obtained as a stand alone package. Information on Performance Probe may be obtained HERE).
If the system has been configured to perform automatic
downloads of software updates, it can appear to cause
periodic, random delays. Typically during the download, network
activity will go up as will disk activity, and when the
installation starts, both drive and CPU activity can skyrocket.
Fortunately automatic updates can usually be controlled by the
user.
Resolution:
The user may either disable the features associated with automatic downloads and updates and initiate them manually. If needed, the system may be monitored for this activity using Activity Monitor (provided with the operating system) or using Performance Probe (Performance Probe is included in the Scannerz package or may be obtained as a stand alone package. Information on Performance Probe may be obtained HERE). In our opinion, this generally shouldn't be necessary because most automatic updates don't occur that frequently, but it might be worthwhile to monitor it just to ensure something else isn't wrong with the system.
Anti virus software can be notorious for causing not
only delays, but sometimes lockups. Some anti-virus software
needs to be "told" which applications on a system are allowed to
gain access to resources. Most come preconfigured with many
application and the operating system itself already allowed to
run, but when a new, "foreign" application comes along that the
anti-virus software doesn't recognize, it can delay it, subject
it to extensive monitoring, or even block it completely until
the user "tells" the anti-virus software that the application is
allowed to run on the system.
Resolution:
Any time anti-virus software is being used, if "mysterious" lock
ups start occurring, check the logs for the anti-virus software
(if available) and see if it's blocking applications. It may be
necessary to configure the anti-virus software to allow
applications that appear to be intruders so they can function
properly. As a quick check immediate disabling of the anti-virus
software may restore the system to normal functioning. Viruses
have typically not been a problem with OS X in the past, but
that doesn't mean they won't be a problem in the future.
If a running application locks up for no apparent reason and
it's application specific it could be a bad sector on a hard
drive or a bad block on an SSD. Assuming these have already been
checked and no problems were found, the problem is likely with
the application, a configuration setting that's changed with the
application, or if the OS has just been updated, the application
is no longer fully compatible with the operating system.
Resolution:
If the software is configurable, verify that none of the
settings have become corrupt or set to values that would cause
the application to lock up. Use Disk Utility to
repair the permissions on the volumes to ensure that a
permissions setting has not changed in such a manner that the
application cannot read or write data as needed any longer. If
an OS has been upgraded to a newer version it may be necessary
to contact the vendor of the product to find out if an
incompatibility exists, and what workarounds are available.
If a drive is no longer seen by the system or won't boot and the
drive is in working order, it's likely a software problem either
with the operating system or a third party driver or kernel
extension. This type of problem typically occurs after either an
operating system update or a driver or kernel extension update.
Other possibilities include:
If a drive has suddenly become invisible and there were no
operating system or driver updates, refer to the corresponding
sections associated with the links titled Drive Problems
and System Problems at the top of this page because it's
very unlikely the problem is software related.
Resolution:
The first thing to do, if possible, is boot from an external
drive or recovery partition and run Disk Utility to
repair the permissions on the drive. If the system is using
third party drivers or kernel extensions, check with the vendors
website and see if they have information about possible
incompatibilities and workarounds. If critical files have been
deleted either accidentally or by a "cleaning" utility, the
files will need to be restored.
If the drive and system are known to be in good working order, drive ejection is most likely an operating system bug. The symptoms of this particular bug typically occur after the system goes to sleep and when it wakes up a dialog indicating the drive was improperly ejected appears. We've either seen first hand or had reports of this happening on MacOS 10.8, 10.9, and 10.10. Whether this is actually an operating system bug or hardware vendors failing to meet standards is debatable by some.
If the drive won't mount and the system and drive are known to
be in good working order, it's quite possible some of the
permissions on the drive have become corrupt and need to be
repaired.
Resolution:
If the drive is ejecting after the system goes to sleep, in
some cases the problem can be alleviated by opening System
Preferences, selecting the Energy Saver option,
and deselecting the Put hard disks to sleep when possible option.
You may also wish to check with the drive manufacturer to see if
they have a work around for the problem.
If the drive won't mount and it and the system are known to be
in good working order it's most likely that a permissions
setting has become corrupt. This can be corrected by booting
from a recovery partition or another drive (such as an emergency
boot drive, a clone, or another system using Target Mode)
and using Disk Utility to correct the permissions on the
drive.