Reinstalling 10.8.2 - what will I lose?

[Benbikeman]

First, I have a clone and two separate Time Machine drives, so I'm covered if something were to go horribly wrong.

My question is, in a successful reinstallation of Mountain Lion from the recovery partition, what exactly gets lost in the way of settings and preferences? I just want to know how much time I need to set aside to restore everything to the way it was, which will influence when I will do it.

The reason for the reinstallation is a major problem with the Apple Mail app. It takes an age when clicking from one account inbox to another (sometimes several minutes).

 

[Weaselboy]

Do you plan to erase Macintosh HD and reinstall Mountain Lion, thus starting fresh? If that is what you are planning it really depends a great deal on your level of familiarity with OS X and how many apps you have installed and how much you have customized things.

If you have a fairly bone stock setup, just copying apps and documents back over could be done in as little as a couple hours. I know with all the tweaking and things I have done, it would take me at least half a day to get back where I am now.

If you mean just reinstalling Mountain Lion over top of the existing install without erasing Macintosh HD, you will not need to reconfigure anything. All your settings and data will still be there.

 

[Benbikeman]

If you mean just reinstalling Mountain Lion over top of the existing install without erasing Macintosh HD, you will not need to reconfigure anything. All your settings and data will still be there.

This.

So I don't lose any settings, preferences, nothing at all?

 

[madmin]

MigAss

If you have a backup you can wipe your system and do a fresh install and then use Migration Assistant to bring over all or a selection of settings, users and other files. It's not perfect for everything but it's very handy and saves time.

You can use Timemachine backups of course but any disk or disk image can be used as the source of your settings or files as long as it's mounted before running Migration Assistant. For example if you backup using SuperDuper to a disk image just double click it to mount it beforehand. Migration Assistant requires you to close all other applications but doesn't ask you to reboot.

If the backup is of a OS X Server system you can only chose between importing everything or nothing, the usual options are greyed out.

You can also migrate across ethernet, wi-fi, firewire or usb cable, a target disk system or from a Windows PC.

It's a good idea to check your system preferences, applications settings, folders etc to ensure everything has transferred as expected. It works for me.

 

[Weaselboy]

This.

So I don't lose any settings, preferences, nothing at all?

That is correct.

 

[Benbikeman]

If you have a backup you can wipe your system and do a fresh install and then use Migration Assistant to bring over all or a selection of settings, users and other files. It's not perfect for everything but it's very handy and saves time.

It's not bad, but you actually lose a lot. It took me a day to restore everything after a migration.

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That is correct.

That's great, thanks for the info, can now go ahead and do this sooner rather than later.

 

[xgman]

There may be a couple minor things such as if you have unhidden the user library.

 

[Benbikeman]

Ok, cool, that's easily sorted

 

[Benbikeman]

Thanks again for the reassurance on this. Reinstalled and indeed lost nothing.

Unfortunately it hasn't solved the problem with Mail, so clearly the Mail folder is corrupt in some way. It's all IMAP, so I can delete the folder, recreate the accounts and then resync.

I did have a glitch doing that when switching from Thunderbird to Mail, though, so will leave it for a quieter time.