Is a clean install worth it?

Discussion in 'OS X Mountain Lion (10.8)' started by squidkitten, Jul 19, 2012.

  1. macrumors 6502

    Hello! I have a mid-2010 MBP and I'm considering doing a clean install of Mountain Lion. I upgraded to Lion last year and I felt like my computer got a tad sluggish. I've gotten used to it by this point, but I'm worried that installing Mountain Lion might have the same affect.

    I've been seeing posts about doing a clean install, and I was wondering if this would help speed up my computer a bit? I've been experimenting with ~technical~ stuff (laughing at myself right now) ever since I joined these forums and started toying around with my Apple devices some more, but I've got a lot of stuff invested to this laptop and I'm a little skittish when it comes to messing with it.

    I don't have an actual time machine, but I do back up regularly on an external hard drive. Will I be able to do my clean install using that? Also, will doing a clean install take away all my apps? I really don't want to lose Photoshop, and I don't know if my student version has another product code to reinstall. What is the process of restoring apps, do I have to reinstall them manually?

    Do you guys think a clean install is worth the time, or should I just upgrade the same way everyone else does?

    Any help is appreciated :)
  2. macrumors member

    Yes, you'll have to reinstall apps manually. What I might recommend in your case is to make a Time Machine backup to an external drive, then clean install Mountain Lion and then restore from the Time Machine backup. While it's possible there's "junk" that will still come along, the restore has the effect of defragmenting your drive, and the ML system files will be loaded on the disk first.
  3. macrumors 6502

    Okay great. I saw a guide floating around on here, so it's safe to say that if I follow those details, I shouldn't have a problem?

    Also, if I have apps such as Pages or Keynote downloaded from the Mac App Store, I can restore those downloads through the store as well, right? For my Photoshop CS4 program…if I don't have an additional product code, will I not be able to reinstall it at all? Or do you think that I can use my current code since I'm installing it to the same hardware.

    Thanks for your help!
  4. macrumors 6502

    Yes, in App Store you have a 'purchased' tab just linke in iOS, you can re-download all your purchased apps for no fee.

    Where did you see the guide to the clean install? Can you link it please? :)
  5. macrumors 6502

    If you bought Photoshop and have a legit serial number, of course you can reinstall the program. No worry here.

    If there is any "trouble" with online serial activation of Photoshop (which i'm sure there won't be), contact Adobe and everything will be fine. You bought the software and reinstalling software from time to time is perfectly normal.
  6. macrumors 6502

    Its a waste of time if you ask me. Just install it like everyone does then do a repair permissions. Simpler and easier :)
  7. macrumors member


    I always do a clean install whenever new OS X releases come out. I know it may seem like a waste of time, but I tried upgrading in the past and often ran into some strange issues which were always cured when I did the fresh install of the same apps and settings. The fresh reinstall also makes system faster and saves the disk space which is important in my case, since the OS is kept on SSD.
    However it's important to maintain your system with this "eventual clean reinstall" mentality. Obviously, all work files, documents and media are kept on the separate partition. I also keep log of all apps I install or system changes that I want to keep. I researched in which files the specific system settings or settings for specific apps are kept. In addition to full TimeMachine backup of the system, I keep a synced copy of those settings files on Dropbox and I have a script that would instantly put those files in the right places after a clean reinstall. Such approach makes reinstalling easy - the steps are:

    1. Perform a full disk image backup of the existing system partition (I use DiskImage, some people prefer SuperDuper)
    2. Wipe the system partition and perform a fresh install of new OS
    3. Set up the user accounts, install applications
    4. Run the script restoring system and application settings
    5. Wait for the cloud data (like mail, calendars, rss feeds, etc.) to sync up.

    It does take some time to set up a routine like this but in my case it pays off in less time dealing with issues between the OS releases.
  8. macrumors regular

    Never had a problem upgrading a score or so Macs. Altogether perhaps 30-40 upgrades from 10.3->10.4 onwards. YMMV of course...
  9. Moderator


    Staff Member

    I used to go the upgrade path, but from what I see here people who upgraded to ML haven't seen any problems as opposed to a clean install.
  10. macrumors 6502

    Thanks for the help everyone! I'll consider all your information while making my decision!
  11. macrumors 65816

    Clean install = Waste of time.
  12. macrumors 6502a


    I have to agree with the opinion that a clean install isn't worth it, unless you are super picky with your system and are just paranoid of upgrading. The upgrade process is much better than it use to be.
  13. Guest

    Same here. A simple upgrade is particularly convenient if you have a dual SSD/HDD setup with OS and apps in the SSD, and the rest of the stuff in the HDD with a few symlinks.

    Besides, TM doesn't recover to non-boot drives; so you will need to copy a lot of things manually and TM won't be of any help.
  14. macrumors regular

    Totally Agree here, been on ML from Beta 1, (I am a Registered Developer) and I have not had any issues with the GM. Just update and "Repair Permissions" and you will be good to go. Reinstalling all your software is a real waste of time not to mention having to redo all your personal settings in said software.
  15. ugp
    macrumors 65816


    From Snow Leopard to Lion I did an Upgrade and had no issues. Everything to me seemed fine and no slow downs.
  16. macrumors 68030

    This will be nearly identical to doing an upgrade, but with more work involved.
  17. macrumors 6502


    I have run into a few issues with doing an upgrade in the past. But I have upgraded a LOT of Macs over the years. Personally I like to do a clean install just because I like to keep everything nice and clean. I do a clean install every 8 months anyway. But thats just me being picky about cleanliness. :D
  18. macrumors 68030


    It's not a complete waste of time, it's just your preference not to. The upgrade from Lion to ML leaves quite a lot a crap around and a fresh install of ML is much leaner. And yes, I've done a clean install of Lion and then immediately upgraded to ML. I've also done a clean ML install.

    A fresh install of Mountain Lion shocked me in that it only took up 6.5-7GB.

    The way I have my backups setup it takes me less than an hour to get fully setup.
  19. macrumors 6502

    Ive upgraded form Snow Leopard > Lion > Mountain Lion GM on my 2010 MBA. No issues and the computer is performing well. I will try to do a complete reinstall when ML is released since Im giving away the MBA.

    Is there an option during installation for clean install?
  20. macrumors 68030

    Not specifically. You have to make a USB installer to boot from, load up Disk Utility once you've booted from the installer, erase the internal drive, then install. A little more complex, but not too bad.
  21. macrumors 6502

    Sounds fair enough. How do I make the USB installer?
  22. macrumors demi-god


    Here you go.
  23. macrumors regular

    I am not so sure everyone upgrades like you said , in my opinion most mac users I know do a new install or archive install , When Mountain lion eventually comes out I would recommend you do a archive and install or just a new install . Just make sure you back up before doing either of those things including just a upgrade . If you bought your apps from the app store you should be able to redownload them and icloud should be able to do that for you . If you bought your apps from other places I really do not know .
  24. macrumors 6502

  25. macrumors 68030


    Ever since I upgraded from SL to Lion my boot time has increased from less than a minute to over 7 minutes, so I am definitely doing a clean install of ML. There's a lot of stuff in Application Data that I'm sure is no longer required, and there's a lot of apps that left a load of junk on the system that I have uninstalled. Then there's cache files, drivers, extensions that I'm unable to track down but I know they're uselessly there, taking up whatever resources they need.

    It will be a major pain in the *** to reinstall every single app, set the preferences to the way I like, restore all the folders and organise all the minor but annoying stuff like icons, the damn launchpad, shortcuts.

    I don't even know how to restore iCal, and where the database is kept, and how to set up Mail to work nicely with Gmail (not the crappy default way that would still mark messages as Unread on your iPhone even though you've already read them on your Mac). As I remember this was an extremely complicated thing to do, and I'm dreading to have to do it again.

    Then there's all the annoying default settings: icon spacing, icon size, sorting order, sidebar icon size, default applications for file types, getting QuickTime 7 back, etc…

    It's a hell of a lot of work but it's hopefully worth it, and there will probably be at least some disk space advantage, as I'll be too lazy to reinstall most apps that I don't need immediately, so I'll end up reinstalling them if and when I do need them. Then of course you end up not knowing if you have a certain app already or not.

    It's still better than Windows! Where you have to screw around with dozens of drivers that simply don't work and crash your system.

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