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
If you are getting this error on 10.7
“Image Capture Extension is trying to modify the printer settings, Type the name and password of a user in the Print Administrators group to allow this”
it is most likely down to the User not running as admin, with a scanner connected to the machine
the simple way of resolving this is to add the User with the problem to the _lpadmin group
to do this, open Terminal and type the following
dseditgroup -o edit -p -a usershortname -u adminshortname -t user _lpadmin
replace usershortname with the short name of the account having the problems and replace adminshortname with the short name of an admin account that you know the password to
once you hit enter it will say ‘Enter User Password’, but you MUST enter the password of the admin account you entered in the command
to verify that this has worked type the following into Terminal
Check the group membership values at the bottom of the info that it shows and you should have all the admin accounts from the machine and the user account that you just added to the group
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
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%.
This is the most simple of maintenance tasks and one of the most overlooked, many people will take their machines to shops as they believe their machine has a serious problem, which can usually be fixed by this one task.
To do a permissions repair you have 2 options, using the Disk Utility app (recommended for most users), or using the command line, which is just as easy, but some people may not be that comfortable doing it this way.
So first, I’ll go through the Disk Utility method, this application is located in /Applications/Utilities
Double click on the application to start it up, now on the left hand side you will have a list of drives connected to your machine currently, on a MacBook Air you may only have your main hard drive listed, on a Mac Pro you may have several hard drives, a couple of SuperDrives, maybe some external USB drives etc.
The one you want to focus on is your system drive, this is usually the top one, but you want to click on the Volume, not the actual hard drive, the volume is usually just underneath with the same hard drive icon, but slightly indented from the edge, on a standard Apple installation this will be called Macintosh HD but it can be named anything.
This will chug away for a while, if you do this regularly then it will only take a few minutes, but if you have never done it then it could take many hours.
Once done I’d recommend rebooting your machine and you should notice an improvement in performance, the reason for rebooting afterwards is I’ve found that quite often some applications or services that had issues starting up before the permissions repair
will end up in some sort of crashed state, so the repair won’t appear to have resolved anything, rebooting causes all of these items to restart and as they should now have the correct permissions and will be able to run correctly, thus not crashing, and not causing a system slowdown
Next I will run through the command line guide to this.
Open Terminal which is located in /Applications/Utilities
sudo diskutil repairPermissions /
this will prompt you for your admin password and will again chug away until done, you will recieve a better idea of its progress as it has a progress bar with a percentage completed, which the GUI option doesn’t have
All thats left to say is make sure you do this regularly, After every major software update or installation should be fine
I have done a video running through a Repair Permissions here