Restoring OS X

Discussion in 'iMac' started by webpoet73, Mar 14, 2013.

  1. webpoet73 macrumors regular

    Joined:
    Jul 29, 2010
    #1
    I have a question about post-installing OSX...

    Is it better to
    a) treat it as new and re-install apps and re-copy the data over from an existing backup
    b) Use the user migration to pull users (and applications) from existing backup

    Option b would definitely be easier. But would there be any advantage to option a?

    I am seriously thinking about doing a full clean install of Mountain Lion on my iMac. It's three years old and been through Snow Leopard, Lion, and now Mountain Lion. I am thinking a clean install might boost performance a bit.
     
  2. rkaufmann87 macrumors 68000

    rkaufmann87

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    Dec 17, 2009
    Location:
    Folsom, CA
    #2
    I think many people on this forum will disagree however when I had my 2007 iMac I never did a clean install, that was after migrating from Tiger to Leopard to Snow Leopard to Lion and finally Mt. Lion. In short 5 totally different OS's and I never had one problem. When I sold the machine to my friend I did a clean install of Snow Leopard because the Mt. Lion license isn't transferable.
     
  3. AppleFan360, Mar 15, 2013
    Last edited: Mar 22, 2013
  4. trustever macrumors 6502

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    Jan 14, 2013
    #4
    If you have done a lot of install/remove apps in the past I would only transfer with Migration Assistant the user(s) and reinstall all the apps manually.You know that when you remove an app it always leaves some rubbish behinde and probably you don't want to move it forward to the next OS
     
  5. Weaselboy Moderator

    Weaselboy

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    Jan 23, 2005
    Location:
    California
    #5
    If your system is working okay now, there really is no good reason to go through all the hassle of a clean install.
     
  6. webpoet73 thread starter macrumors regular

    Joined:
    Jul 29, 2010
    #6
    Once booted, it works fine. Every re-boot, after getting into the desktop, the hard drives very hard for 5 to 10 minutes. I get concerned. I have done all of the preventive measures in Disk Utility.

    Unfortunately, even though I have a Seagate drive (ST31000528ASQ), my iMac did not qualify for the warranty replacement.

    I don't have the skills to pull the iMac apart and replace myself. Just reading on the Apple Support forums, that might not be so easy. Something to do with the temperature sensor...

    I may not do a clean install, then. Thanks, guys.

    If I had to, could it be run off of an external firewire drive? In case of disaster...
     
  7. blueroom macrumors 603

    blueroom

    Joined:
    Feb 15, 2009
    Location:
    Toronto, Canada
    #7
    If you're not backing up, then get a backup solution. Time Machine is pretty handy and will help with a fresh install and restore because it won't overwrite system files.
    Also put the OSX install on a USB flash, much faster install.
     
  8. webpoet73 thread starter macrumors regular

    Joined:
    Jul 29, 2010
    #8
    Backup plan

    Yes, I do have a backup plan.

    a) I have ML install on USB stick
    b) Time Machine on a local USB hard drive
    c) I backup every couple of weeks (clone) to a hard drive that I take off premises in case of disaster.

    I guess that a clean install is not needed, but it's been so long, it feels like it needs one.
     
  9. xgman macrumors 601

    xgman

    Joined:
    Aug 6, 2007
    #9
    You could just do the clean install and select the transfer user settings and files via a time mach backup.
     
  10. AppleFan360, Mar 20, 2013
    Last edited: Mar 22, 2013
  11. Weaselboy Moderator

    Weaselboy

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    #11
    That is not a "clean install" and will put OP exactly where he is now. A TM restore will put every last setting and app back on the drive. If there are problems with the install, they will just be "restored" with this method.

    A true clean install is a erase of the disk then install of the OS, followed by the manual installation of every app and setting.
     
  12. MatthewAMEL macrumors 6502

    MatthewAMEL

    Joined:
    Oct 23, 2007
    Location:
    Orlando, FL
    #12
    BTW- Does anyone know if the AppStore version of Mountain Lion has been updated to 10.8.3?

    I would like to update my 'rescue USB' to include my 2012 Mini and iMac.
     
  13. Weaselboy Moderator

    Weaselboy

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    #13
    Sure has.

    [​IMG]
     
  14. AppleFan360, Mar 21, 2013
    Last edited: Mar 22, 2013
  15. benwiggy macrumors 68020

    Joined:
    Jun 15, 2012
    #15
    It seems to be a idea from people who have used Windows regularly that in the event of any problem, the first thing you should do is to reinstall the OS.

    On OS X, the OS is almost never the problem, and should not need reinstalling unless you've deleted or overwritten some system files. (Or given yourself write permissions to the whole disk, etc.)

    You don't need to reinstall the OS because "it's getting slower", or as some kind of annual pagan ritual of cleanliness.

    Most problems are likely to be fixed by emptying caches, deleting user preference files and removing third-party software. A clean install will of course empty the caches, so that's probably why you get an improvement. (Safe Boot will also do the same, so that's worth trying.)
     
  16. Weaselboy Moderator

    Weaselboy

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    #16
    Yes, it will. If you erase then reinstall the OS, and then use Migration Assistant to pull in data from a backup, that may help. But if you reinstall the OS then "restore" from Time Machine, it overwrites the OS install you just did with the OS and data from the Time Machine backup. It is a complete waste of time and accomplishes nothing at all.

    I think you may mean import to a new install with Migration Assistant rather then the "restore" you keep mentioning.
     
  17. AppleFan360, Mar 21, 2013
    Last edited: Mar 22, 2013
  18. AppleFan360, Mar 21, 2013
    Last edited: Mar 22, 2013
  19. benwiggy macrumors 68020

    Joined:
    Jun 15, 2012
    #19
    Yes, my point exactly. Reinstalling is the LAST thing to try, not the first.
    In ten years of using seven different versions of OS X across four computers, I've reinstalled the OS about three times. And probably not all of those were necessary.

    Most system files are read-only, and not modified during their life. It's only the files in the "working" areas that are likely to cause you bother. Most of those in the user's Library folder, plus the top-level Library folder. You can easily sort out issues in those areas without doing a nuke and pave.
     
  20. Weaselboy Moderator

    Weaselboy

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    California
    #20
    I'm sorry, but you are far far off here. Time Machine most definitely backs up the OS. There are countless threads here about users putting in a new, blank drive and doing a full system restore (including the OS) from a Time Machine backup. I just did it myself two weeks ago on a friend's Macbook Pro.

    Read this.

    [​IMG]

    You can also read more about it here.

    Please read up a bit on this, because your posts are incorrect and it is confusing people.

    A Time Machine backup does include the entire OS and it can be used to restore a system onto a completely blank disk without first installing the OS.

    Again, if you install the OS, then "restore" from Time Machine, you just installed the OS for absolutely nothing because the TM restore wipes the drive and replaces whatever was there with the restore. Read this.

    [​IMG]

    I know it is very confusing, and frankly Apple has not done a very good job explaining how all this works, but you are quite wrong.
     
  21. AppleFan360, Mar 22, 2013
    Last edited: Mar 22, 2013
  22. Weaselboy Moderator

    Weaselboy

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    Jan 23, 2005
    Location:
    California
    #22
    Time Machine backs up the entire disk, including the OS. If you read the links I posted you would see this.

    You want more proof. Okay... here, here, and here.

    I don't see what is so difficult to grasp here. Just about every other day there is a post here about a forum member using TM to restore to a blank drive. So you think they are just making that up?
     
  23. webpoet73 thread starter macrumors regular

    Joined:
    Jul 29, 2010
    #23
    Hmmm... ok. I thought that a re-install would solve my iMac drive problem of constantly reading for like 5 minutes after a re-boot. Sometimes, it feels like it may never stop reading. I am kind of getting worried about the drive, itself. I can't repair an iMac, myself. I fear how much Apple will charge to do it.

    I have had serious thoughts about the next Mac being a Mac Mini with a good 27" monitor. I won't be able to do that for a while (unless the iMac dies) because I just bought a Macbook Air, which could power a 27" monitor (but 128GB SSD is severely limited compared to 1TB drive...)
     

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