Q&A: MacFixIt Answers

MacFixIt Answers is a feature in which we answer questions e-mailed in by our readers.

This week people wrote in with questions about missing Recovery HD partitions after cloning a Lion installation, upgrading the processor on Mac systems, and the requirements for running permissions repair routines when updating the system. We continually answer e-mail questions, and though we present answers here, we welcome alternative approaches and views from readers and encourage you to post your suggestions in the comments.

NOTE: The "contact us" box on the MacFixIt page is now available for you to use when e-mailing questions. For now it is available if you go to the MacFixIt front page, but you can also still use the existing methods of contacting us.

Question: Missing recovery partition after cloning OS X Lion
MacFixIt reader "Kunio" asks:

I used SuperDuper! to clone the internal drive of a Mac Pro running OS 10.7.2 onto the internal drive of a MacBook Pro (MBP). The MBP boots and runs fine. But, I have noticed that it is missing the usual recovery partition when I try to boot it with the OPTION key down. Would you have any idea as to where the recovery partition may have ended up?

Answer:
SuperDuper performs file-level cloning on the system, so when you cloned the drive you copied all files exactly as they are (in terms of all their properties and meta data). The limitation of this type of cloning is you can only copy one volume at a time, so when you cloned your boot volume to the new drive you left the recovery partition behind. To clone multiple partitions you will need to use a cloning tool that can do "block-level" clones. Here is an article with some information on the difference, and some tools that have this feature.

Question: Upgrading processors on Mac systems
MacFixIt reader "BoogieStik" asks:

My 2011 iMac has a SandyBridge i7 2600. Intel says that their upcoming Ivy Bridge processors will be plug-compatible with their Sandy Bridge processors. As I understand it, this means that users like me can replace our Sandy Bridge processors with Ivy Bridge processors for increased performance, provided we have the appropriate firmware/BIOS update. Where would we get this update, and how would we install it?

Answer:
I don't recommend doing this on systems you depend on. Though some people have done drop-in upgrades to systems in the past with success, you do take a chance of wasting money for an upgrade that won't work, and risk breaking your system when disassembling it for the upgrade if you're not careful.

Question: Requirement for repairing permissions on OS X
MacFixIt reader Michael asks:

I was wondering if you could shed some light in my following doubt. Often, I write in the Apple forums about how Mac OS X Updates are running in other users Macs. I get great feedback from those posts but there's always a poster saying that before the update, I should Repair Permissions, and another poster telling me to do it (Repair Permissions) only after the update (and in some other cases, I will get the occasional user saying that Repairing Permissions are not required).

This mix of responses have me really confused on what is the purpose of Disk Utility Repair Permissions function. Would you mind clarifying this doubt?

Answer:
The permissions repair routine is only necessary if your system is experiencing problems that are related to the accessibility of files. Running the repair routine will not hurt anything, but because it can help fix some problems, some people get a bit overzealous when recommending it, or just recommend it blindly as a step to take for any problem with the system.

Permissions attributes can change during regular system use, and sometimes the permissions requirements for files may be purposefully changed by Apple in an update; however, new files in an update should already have the appropriate permissions and not require a repair.

Most of the time changes to file permissions during general use are benign subtleties that do not affect access to the files, but despite this the change is noted and reverted when you run a permissions repair routine. Some people may see this as a problematic error that needs fixing when ultimately it doesn't really matter.

When it comes to system updates, you can invoke a permissions fix before or after updating (or both) if you wish as a general maintenance routine (just like checking the air on your tires), but this is not a necessary thing to do. However, since it won't hurt and can potentially help "if" there is an actual permissions problem, then running it can be recommended at any time.

Besides when there is an actual permissions problem, there is no right or wrong answer as to when is best to run a permissions routine.

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