Clean install or Upgrade ML

Discussion in 'OS X Mountain Lion (10.8)' started by V6Pony, Jun 20, 2012.

  1. V6Pony macrumors newbie

    Nov 28, 2010
    Southern Illinois
    I have a 6.2 MBP. 2010 model. I have upgraded Snow Lion and Lion. Everything works well. So I was just wondering if I should do a clean install of ML this time? I have an external disk that I can use to save my home folder. I also use a online backup service. Not sure how to go about doing a clean install from a down load from Apple. Perhaps I can find a how to some where. What do you think?
  2. antoniogra7 macrumors member

    Jun 12, 2012
    I think is always better to do a clean install, but if it is a mess for you, just upgrade. To do a clean install you can extract the .dmg inside the Mountain Lion app and burn it on a DVD or a USB disk (pendrive or SD card).
  3. Macman45 macrumors G5


    Jul 29, 2011
    Somewhere Back In The Long Ago
    Since ML will be download only, I'm sure Apple will provide the USB stick install option that they introduced for Lion.

    Saves a lot of time and trouble...I always prefer a clean install, but may go down the upgrade path first to see whats what.

    I have recently clean installed Lion on all three of my Macs...A tedious business putting everything back again...:)
  4. andy8 macrumors regular

    Jan 6, 2009
    Unless the machine hasn't been performing like a Mac should and not been cleanly re-installed recently (like a year or so).I don't see the advantages of clean installing Mountain Lion from Lion.
  5. Sky Blue Guest

    Sky Blue

    Jan 8, 2005
    They've said they're not doing that this time.
  6. clukas macrumors 6502a


    May 3, 2010
    I was just wondering the same thing. I did an upgrade to lion from Snow Leopard. About 6 months later I did a clean install but did not notice any performance difference. I think I will do a clean install this time however.
  7. FluffyPop macrumors member

    Aug 20, 2011
    I'm going to do a clean install. I keep hearing that it's not really necessary, but the habits acquired during years of exposure to Windows are difficult to get rid of ;-)
  8. baryon macrumors 68040


    Oct 3, 2009
    I upgraded from Leopard to SL, then to Lion, and now my system takes about 7 minutes to reboot. Everything else appears to be perfectly fine, but what if this slow boot issue can be solved by doing a clean install? Also, maybe my system is actually slower than it should be, but I just don't notice it since I'm so used to it…

    I'll upgrade to ML first, and if it doesn't solve the slow boot, I will do a clean install.
  9. clukas macrumors 6502a


    May 3, 2010
    7 minutes is a very long time for a reboot, a clean install should almost definitely take care of this.
  10. stainlessliquid macrumors 68000

    Sep 22, 2006
    I did an upgrade to Lion and that was a mistake, not everything works properly after an upgrade. Most does but its never perfectly issue free.
  11. dacreativeguy macrumors 68020

    Jan 27, 2007
    Snow Leopard to Lion was a big change, and a lot of apps were incompatible (especially the old apps that required Rosetta). Lion to Mtn Lion is a smaller change under the hood. Haven't heard of too many apps not functioning.

    It looks like Apple may be taking a similar approach to OSX as it has with the iPhone. Every 2 versions are a big release. Leopard and iPhone 4, Snow Leopard and iPhone 4s, Lion and iPhone 5, Mountain Lion and ???? -- we'll see.

    That being said, a clean install and migration from Time Machine backup does have some benefits. It cleans out any cruft the old OS may have created and also serves as a defrag process. If you format the drive and install fresh, all of the block gaps you've developed over the years go away. OS X doesn't have a huge issue with degragmentation, but every little bit helps and this is a perfect time to take care of all the minor issues in one fell swoop!
  12. andy8 macrumors regular

    Jan 6, 2009
    I did a clean re-install of Lion a week ago. Now my system is working perfectly.
    Do you reckon I should clean reinstall Mountain Lion in a few weeks time ? Would that add to significant advantages ?
  13. clukas macrumors 6502a


    May 3, 2010
    since you have already wiped all your data from your mac I guess it would not hurt to wait a few weeks and repeat the clean install with mountain lion. Just make sure you keep all your data backed up.
  14. stisdal macrumors 6502


    Feb 28, 2010
    Migration Assistant

    OK, so what are the feelings of doing a clean install, then using migration assistant to import all your files and non app store apps from a separate partition? (As opposed to just doing an update)
  15. andy8 macrumors regular

    Jan 6, 2009
    With that in mind, I would like to know about Migration assistant vs time machine backup. I'm used to time machine backup but it seems Migration Assistant may offer something better...
  16. dacreativeguy macrumors 68020

    Jan 27, 2007
    It's really the same thing. Time machine backups don't include the OS files, so for the most part, restoring from TM and migrating from TM during OS install are very similar. In both cases, you have to install the OS before pointing to your TM backup.


    Most likely it will be fine. Unlike Windows, OS X keeps the OS files completely separate from user data and applications, so you can swap out the OS and not affect anything else. Since you recently cleaned things out and defacto defragmented the drive, it should be ok to update.

    That is what Apple wants most users to do anyway. Since Lion, they have removed all of the install options (clean install, copy and upgrade, etc), it must mean that they have a lot of confidence that upgrades won't have any problems.
  17. Mal macrumors 603


    Jan 6, 2002

    Not unless you specifically exclude the OS. By default the OS is backed up along with user data. You have to boot from the install disk or recovery partition, but you can simply select "Restore from Time Machine Backup" from the Utilities menu or main screen (depending on the OS) and it will restore the system along with the data without doing a separate OS reinstall.

  18. dilgit macrumors regular

    Sep 24, 2010
    I really don't know what to do. I might receive my new BTO MacBook Pro with retina display, loaded with Lion, on the very same day that ML will be released. Should I upgrade immediately and only than connect the new RMBP to my external thunderbolt drive with TM? Will this install all my software like CS6 etc?
  19. Killerbob macrumors 6502a

    Jan 25, 2008
    For the last many times, I have used the "install, then migrate" approach on all my Macs. It has worked flawlessly every time, on all machines, MacBooks and Pros.

    I start by taking a new TC Backup of the target machine. I get the new OSX DMG file created, put it on a USB stick, boot and create the partition on my two SSDs in RAID0. When all is up and running, I use Migration Assistant to transfer all applications, user settings and preferences.

    All my data is on my NAS anyway, so it works, and my Home folders a re seldom filled up with anything but applications.

    It is not the fastest way, but it works, and I have OSXes that boot in 25 seconds or less.

  20. MacGurl111 macrumors 65816


    Feb 4, 2010
    Same here. I did the same and I was constantly get that stupid rainbow timer, laptop was awfully slow and rebooting was a pain because it took forever to get pass that apple icon page, and there's so much more.. Save yourself the trouble and do a clean install. :( Learned my lesson.
  21. Grey Hound macrumors newbie

    Jun 17, 2012
    In the province.
    Sorry to hear your stories... What is causing all this issues?
  22. haravikk macrumors 65816

    May 1, 2005
    The Mountain Lion installer should presumably be the same as the Lion one, in which case it will install the recovery partition first and complete the installation from there? So you shouldn't have any need for a disk of any kind.

    While I always believe a clean install is better than an upgrade, it really depends on how your machine is performing. If you haven't noticed any sluggishness, and you're not in the habit of installing lots of non-standard apps then I don't think anything so fundamental has changed in Mountain Lion to recommend a clean-install over simply upgrading.

    In my case I almost always have developed new quirks on my machine by the time the new update rolls around, so I always go for a clean install. Though this time round I'm hoping to have a NAS setup and synced beforehand so I can have an extra layer of redundancy; I always find clean installs a bit hair-raising when my Time Machine backup has the only copy of my data.
  23. Aco Strkalj macrumors member

    Jun 4, 2012

    I purchased the 2012 MacBook Air. I'm eligible for a free Mountain Lion. I plan on performing a clean install. My question is how would I go about it?

    Do I hold CMD+R during the reboot process after I order it from the App Store? This is my first time upgrading the OS.
  24. haravikk macrumors 65816

    May 1, 2005
    Just open the installer and follow the instructions :)
    It should create the new recovery partition for you then either restart automatically or prompt you do-so, at which point it'll start up from there and continue installation, you just need to choose where to install, and whether to erase first.

    The OS X installer really does do pretty much everything for you, you don't really need to do much at all until it's finished, where you setup an account, timezone, enter an Apple ID and whatever else you need to get up and running again.

    It'll also offer to let you restore your machine from a Time Machine backup; I just want to point out that if you have a lot of content then this will take ages since it won't proceed until everything has been copied. I personally prefer to restore from Time Machine manually (copy files across in the Finder) since I can do it in stages that way, but it requires you know where everything needs to go if you want to restore app settings etc.
    If you don't have tons of large files like I do (over 1.5tb in my case) then you shouldn't need to worry about that, just leave Time Machine restore to do its thing till it's finished, the time estimate isn't usually far off once it gets going.
  25. iFanboy Guest

    Clean install is, well, "cleaner".

    I have encountered macs with strange problems after upgrades, that just completely went away after a clean install.

    WARNING - Clean install is only beneficial if you are going to stick with it. A clean install followed by a time machine restore is NOT a clean install.

    I always do a clean install and have never experienced ANY of the reported problems with SL or Lion after people upgraded. YMMV. *shrugs*

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