OS X Lion Upgrade vs Clean Install over Snow Leopard

Discussion in 'Mac OS X Lion (10.7)' started by Glyphism, Jul 3, 2011.

  1. Glyphism macrumors newbie

    Jul 3, 2011
    Hi guys. One thing I can't see any clarification of in the Lion GM installer is the ability to upgrade vs clean install. I just want to upgrade my current Snow Leopard installation, and maintain all existing files/setup etc. I don't want Lion to do a clean install.

    Where in the installation process am I meant to be able to check this? The Customize button is all greyed out and I have no idea of knowing what the installation will do.

  2. BigJohno macrumors 65816

    Jan 1, 2007
    San Francisco
    You can just run the Lion GM installer right in sL and it will install over your current machine and leave everything alone.
  3. Glyphism thread starter macrumors newbie

    Jul 3, 2011
    Really? I'm surprised there is no message or confirmation of any sort. It feels very unlike Apple to leave it so vague and overlook this one critical piece of information for an OS installation?
  4. SirithX macrumors 6502


    Feb 21, 2007
    San Francisco
    Snow Leopard is required for you to install Lion, so to do a clean installation you'd have to clean install SL, then simply install Lion.
  5. Glyphism thread starter macrumors newbie

    Jul 3, 2011
    I understand. I'm after just a straight upgrade as opposed to a clean install. The only thing I need to ensure is that when it upgrades my existing Snow Leopard installation it leaves all my files and apps untouched. That's all.
  6. rorschach macrumors 68020


    Jul 27, 2003
    I upgraded from Snow Leopard without changing any install settings and it just did a regular upgrade, no apps or files were deleted.

    BTW, a "Clean Install" won't touch your files either -- it just moves the old system files ("System" folder, etc.) into a "Previous System" folder and then installs all the system files from a clean slate. Only an "Erase & Install" would touch your files.
  7. Glyphism thread starter macrumors newbie

    Jul 3, 2011
    I see. Ok thanks for clarifying. You're right I was concerned about the Erase and Install option.
  8. ovrlrd macrumors 65816


    Aug 29, 2009
    I don't understand why everyone doesn't just do upgrade. Ever since Snow Leopard came out Apple has had a cool upgrade method that simply replaces the system files with new ones. It is essentially the same thing as a clean install except you still keep all your files.

    The only potential conflicts are with apps or extensions you installed yourself, but you would run into those conflicts after a clean install anyway once you started to install your software again. Because it's so easy to track down the "conflicts" it really isn't necessary. I have had the same "install" since 10.5 (though it used to be on an iMac before I got my Mac Pro) and my Mac is running fantastic with the Lion GM. I just make sure to always remove apps and extensions I no longer need or don't get updated to support the new OS.
  9. rorschach macrumors 68020


    Jul 27, 2003
    Fwiw, someone from Apple wrote on the Developer Forums that there is no reason to do a clean install with Lion because "the upgrade installer is much smarter than it used to be."
  10. torana355 macrumors 68030

    Dec 8, 2009
    Sydney, Australia
    Yeah im usually very fussy and always do clean installs with a new OS but i just did an upgrade to make sure all my Apps worked with lion properly, after reading around i don't think im going to bother with a clean install as Lion GM is working great as it is.
  11. ErikGrim macrumors 68040


    Jun 20, 2003
    Brisbane, Australia
    That is no joke by the way. I had a power outage mid way through the instal of DP1. I thought I was fried, but the computer just booted up and continued the installation like nothing had happened!

    For the record: Erase and install or Clean install has never ever been the default mode of installation. You always had to customise the install for that.
  12. baryon macrumors 68040


    Oct 3, 2009
    The problem isn't "will the upgrade to Lion cause problems?" but rather "getting a new OS is an occasion to clean your computer, should I take advantage of that opportunity?".

    I've never clean installed my Mac for 3 years, and I'm not sure if it's running slower than it used to, as I can't remember what it was like 3 years ago.

    However, I know that in Windows you do a clean install every year or so, and the difference is noticeable, mostly because it removes all the useless processes that start when you log in. On a Mac you can easily keep track of apps that start on login, though, so this might not be an issue.

    Another thing is: what if you have corrupted fonts, corrupted app preferences and whatnot? Maybe they're making your system slightly slower but you'd never find what's doing this, mostly because it's not a single thing and it's not noticeable enough. Now a clean install would remove those corrupted files...

    But then you'd probably end up copying your fonts back, thus copying the corrupted ones back again... or maybe they weren't corrupted in the first place, but got corrupted during normal usage? That was the case with an OS X update lately, but it was later fixed in yet another update.

    Also, I just found 4GB of Cache files in my user Library... Those cache files were from Bridge CS4, that I have removed from my computer 2 years ago. So when you use the official uninstaller for Adobe apps, they STILL leave cache behind, and huge amounts of it. If I would not have noticed, then a clean install would have solved this problem. Maybe there are more cache files around, I just don't know about them...

    Also, some apps just have problems, for no specific reason, and you live with it. Some apps give you an error message and you don't really know why. Who knows, maybe it's a corrupted file that would not get fixed unless you did a clean install.

    By "clean install" I mean Format > Install Lion > Install every app one by one from the original installer > Copy back every single file one by one from a hard drive. Formatting, then restoring from Time Machine won't do a thing. It will copy back your corrupted fonts the same way.

    A true clean install is extremely time consuming, as it requires you to remember all the plugins, settings, preference panes, apps, extensions, and all the tricks you did to get things work when there was no official support. Doing all these can take days and days of frustration, and by the end of it you will probably wish you had just upgraded.

    Computers today are extremely complex and your data is the way you want it, customized like hell. I think that unless you have specific, unsolvable problems, then just do an upgrade.

    I switched from Windows because I hated that you install your OS, lose all your data, and a year later you can start over again... It's never over. Hopefully (and apparently) OS X doesn't require this.
  13. dagamer34 macrumors 65816


    May 1, 2007
    Houston, TX
    Because when I just did a "typical" user upgrade, I found a bug where my Finder windows were always hidden. And there are trillions of Snow Leopard OS configurations and Apple cannot test them all, but you KNOW they tested the heck out of a clean OS (blank hard drive) install.

    It's not really the OS that matters but all of the non-updated software running that causes lots of problems. Especially since Lion hasn't been officially released yet, trusting an in-place upgrade is quite a leap of faith when you think about it.
  14. MartiNZ macrumors 65816


    Apr 10, 2008
    Auckland, New Zealand
    I've gone with "yes" on every other OS X release, and think I will do the same if Lion gives me that option. For tradition if nothing more, but I like to think it is the pinnacle in terms of ensuring everything is as it should be. Things certainly have got better over time, and I've become more trusting of the OS, used to install more frequently than every release, but I like the idea of an excuse for a spring clean ... or as it is in this case, mid-winter, what better a thing to stay in and do when it's so cold out :).

    Plus I actually really enjoy doing all the customisation things again on reinstall - from defaults write entries for iTunes, Dock, Finder, etc. to setting column widths in Finder and Mail to raging yet again about how Finder should have a global window size setting like Windows 7 so that I don't get tempted to open hundreds of thousands of windows fresh to make them all the same....
  15. dagamer34 macrumors 65816


    May 1, 2007
    Houston, TX
    But is it smart enough? The better question really is "Do you have apps or system services installed that break Lion?"

    For your typical user, an upgrade is probably fine because all they do is install non-system apps. But for your advanced user, I'd stick with a clean install because there is likely software that needs an update for Lion otherwise it will wreak havoc in your system.
  16. andytran macrumors newbie

    Apr 19, 2011
    When I updated from Leopard to Snow Leopard, the dock would become unresponsive when I right-clicked on it. A clean install fixed this.

    So I'm planning to perform a complete clean install when upgrading from SL to Lion.
  17. CylonGlitch macrumors 68030


    Jul 7, 2009
    I did an Upgrade install of Lion and now the launchpad has 2 copies of all of the default applications. 2 "DVD Player", 2 "Chess", 2 "iMovie". No way to delete the second copy. :(
  18. macmongral macrumors member

    Jun 18, 2011
    using the gm app as is . it leaves the old app folder in the dock still fans/grid as it did in SL plus lots of little bits left around. A boot from usb stick, partition and then install Lion and you have a different system to use as it should for Lion

    note I said partition not just erase as the former will definable get rid od of left over restore partitions from the DPx installs

    anyway its your system so do as you please :D
  19. Jerome Morrow macrumors 6502a

    Jerome Morrow

    Jun 13, 2011
    United Kingdom
    I upgraded a copy of my Snow Leopard installation (which is from 10.4->10.5->10.6) just to test and the only problems i see is random slowness.

    Also there was problem with kernel not booting to 64 bit mode, but it was my problem. All in all i'd say it's a perfect upgrade with no issues caused by the upgrade process.
  20. oojosheoo macrumors member

    Oct 15, 2008
    I just installed the GM on my MBP 2010 i5 with a OWC SSD. Boy the boot up speed is amazing. When I say "amazing" its still only faster by a few seconds :)

    Anyways my question is if there will be a "reinstall" option once Lion comes out. Could be as simple as buying the official release version of 10.7 and install it on top of the GM?
  21. Heston macrumors regular

    Feb 13, 2007
    I did a clean install of Lion GM without installing SL first. Wiped my HDD.

    For DP4, I "upgraded" over SL

    Both methods worked without a hitch.
  22. Lwis macrumors newbie

    May 1, 2011
    Why do I keep reading this? It's not true, stop misinforming people. Apple are still including the ESD for power users who would rather mount it to a flash drice or burn it to disc. Can we put this one to bed now?
  23. BlackMangoTree macrumors 6502a

    Sep 30, 2010
    This is not supported or recommended by Apple so we shouldn't be telling people to do this.
  24. HelveticaNeue macrumors 6502a


    Apr 24, 2010
    I installed Lion's GM on two machines. A 8 month old iMac and a 2.5 year old MBP. Both installations went perfectly and both machines are runnings silky smooth, snappier than ever.
  25. Jelite macrumors 6502a

    Feb 16, 2008
    I've upgraded from SL and everything's smooth as butter, even fixed my not going to sleep issue.

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