X11 not included in 10.8 (Mountain Lion)

X11 is not included within 10.8’s installation, so you will have to install this seperately, this is simple to do as long as the XQuartz project keeps running

The XQuartz project is an open-source effort to develop a version of the X.Org X Window System that runs on Mac OS X. Together with supporting libraries and applications, it forms the X11.app that Apple has shipped with OS X since version 10.5.

http://xquartz.macosforge.org/trac/wiki

Click on the link under ‘Latest Release’ to gain access to the download link.

Download the DMG and install the package and your X11 apps should work as they used to under previous releases of OS X

Operation on file .vmdk failed

If you are running one of the VMWare products, such as VM Fusion on the Mac, then you may have run into an error similar to this

“Operation on file “/Virtual Machines.localized/VIRTUALMACHINENAME.vmwarevm/VIRTUALMACHINENAME-s012.vmdk”failed.
If the file resides on a remote file system, please make sure your network connection and server where this disk resides are functioning properly. 
If the file resides on removable media, reattach the media.
Choose Retry to attempt the operation again.
Choose Abort to terminate this session.
Choose Continue to forward the error to the guest operating system”

Now this error is one of the most unhelpful error messages, as its completely misleading, the error is caused by not enough RAM being made available by the system, so the simple solution is to reboot, quitting all open applications, and freeing up more system memory.

To prevent this happening again in future try limiting the Virtual Machines RAM allocation to under 3GB, on machines with 8GB+ this should be fine.

Also, make sure that Spotlight is not trying to index your VM, as this may also lead to this issue

You can stop this by opening System Preferences, then click on Spotlight, then click on the Privacy tab, click the + button at the bottom and add the Virtual Machines folder, this is normally located at /Users/USERNAME/Documents/Virtual Machines

Dealing with Directory Corruption

If your Mac is running slow, there is a chance that you could be suffering from Directory Corruption, to find out if you are the you will need to do the following

Open Disk Utility and click on your system volume, then choose Verify Disk

If all is well then it will tell you with the following notification

Verifying volume “Macintosh HD
Checking file systemPerforming live verification.
Checking Journaled HFS Plus volume.
Checking extents overflow file.
Checking catalog file.
Checking multi-linked files.
Checking catalog hierarchy.
Checking extended attributes file.
Checking volume bitmap.
Checking volume information.
The volume Macintosh HD appears to be OK.

If you get any other message, usually in red, then you will need to repair your disk, you can’t normally do this from within the Operating System, so you will need to boot from an external device, or if you are running lion then you can boot to the Recovery HD

Once you have booted from another drive you will have the option of running Repair Disk on the affected drive

If it still cannot repair the corruption then you will need to use another utility, I’d recommend DiskWarrior, it’s just under $100 but it can be invaluable in recovering a system affected by corruption, and if you were to take it into a shop then they would probably charge you more than that to resolve this anyway.

This uses a different method of repair by collecting data from the system and rebuilding the directory structure, there are warnings that it could result in data loss, and as with any kind of system repair there is always a risk of some data being lost, but I have used this program 12 times over the past 8 years and its worked 100%.

Tips for speeding up your Mac

1. Hard Drive Space
You should keep a minimum of 10% of your Hard Drive free to ensure smooth running of your machine, I normally aim for 15-20% free, so I still have a bit of space to play with

If you are unsure of whats exactly is taking up your hard drive then you can use a utility like DaisyDisk (Available on the Mac App Store) to track down those space hogs.

2. Clear Your Desktop
Lots of people use their Desktop as the store for all their files, this increases the amount of time it takes to startup as all of the preview icons need to load, so by storing these files elsewhere in the filesystem then you will improve startup times

3. Disable Login Items
Lots of items starting at login will also slow down your machine, and often, these will continue to run in the background, taking up memory and utilising the processor unnecessarily, to prevent this, do the following

Open System Preferences

Click on Users & Groups

Click on your account in the window on the left

Click on the Login Items tab to the right

Click on the items you no longer wish to run at startup, such as iTunes helper, VM Fusion helper and click on the minus button at the bottom of the window to remove them.

4. Disable Dashboard
I haven’t used Dashboard since 10.4, so I tend to disable it, you can do this by opening a Terminal window and typing the following

defaults write com.apple.dashboard mcx-disabled -boolean YES

then

killall Dock

This will fully disable Dashboard so you will not even be able to run it manually by clicking on the icon in /Applications, to re-enable it if you change your mind then you can do type the following into a Terminal window

defaults write com.apple.dashboard mcx-disabled -boolean NO

then

killall Dock

5. Repair Permissions
I recommend repairing permissions after every software update, but most people don’t have time to do get round to this as well, until the machine becomes slow and unresponsive.

To do this, navigate to /Applications/Utilities

Open Disk Utility

Click on your startup volume (Usually named Macintosh HD)

Click on the First Aid tab and click on Repair Permissions at the bottom of the screen

6. Repair Disk
Sometimes disks will develop directory structure corruption over time, this isn’t a problem if dealt with promptly, but in the worst cases will need attention from a specialist application such as diskwarrior.

To check if your drive needs this doing you can run a verify disk from Disk Utility, as follows

Open Disk Utility (from /Applications/Utilities)

click on your startup volume

click on the First Aid tab and click on Verify Disk

If all is well you will receive a green message signalling the drive is fine

If its not then you will recieve a red message stating the cause of the error

To run a repair disk you will need to boot from a non system drive, such as a Mac OS X Installation Disk, or a home made Bootable USB

Once you have booted from one of those then you will need to run Disk Utility again, and this time click on your startup volume and choose First Aid, then click on Repair Disk.

This may need running more than once, although my recent experiences have shown that it will keep running until it has resolved the issues.

7. OnyX
Finally I use OnyX to clear out a few caches and log files, I’d recommend sticking with the default options with this app, a free download from Titanium Software, just make sure you download the version that matches your Operating System, if you are unsure which OS you are running then you can find out by clicking on the Apple Icon in the top left corner of the screen and clicking on About This Mac

8. Add more RAM
Put as much RAM as you can afford into your mac, I’d recommend the minimum on the following Operating Systems

10.4 (Tiger) – 1GB

10.5 (Leopard) – 2GB

10.6 (Snow Leopard) – 2GB

10.7 (Lion) – 4GB

9. Reboot
A lot of people hardly ever reboot their macs, and for some unknown reason are even strongly against doing this, even though the majority of the time a reboot fixes a lot of issues, I’d always choose this option on a slow running mac, in case there are some applications that have been closed but refuse to release the RAM for the OS to reuse