To time machine or not to time machine

Question

Hi folks,
I have a 2011 iMac (21.5" /  2.8Ghz i7 / 8GB Ram / 1TB 7200 RPM HDD). I have never done a clean instal of the OS. I am now running Yosemite and she's a bit clunky. Logging in takes about 5 minutes. apps are crashing, sometimes they wont even launch, and lots and lots of beach balls!! Ive decided its finally time to bite the bullet and do a clean install of Yosemite. My question is: how heavily should I use time machine for the resotre? I have around 6 OS's worth of updates and who knows how many in app updates. I don't want to bring along any corrupted bits in apps to the new snappy instal. Would it be wise to go and download all the app installers and do a fresh instal of the apps? Or is a recorvery from time machine just as good? Any thing else I should be thinking of when it comes to documents, files and libraries like iTunes or adobe Lightroom??
I have never needed to use time machine for recovery since I migrated to mac in 2011 when I bought this imac. Last time i did a reformat and install of an OS it was windows XP -which I'm glad to have this problem.
Thanks for the wisdom
Dale

Answer 1

dalewestae wrote:
Thanks Drew. I'm in full agreement with you about the clone. It's a good idea for sure.
A)
What I meant by granular is that MA/SA are kind of all or nothing. All apps or no apps. what if I don't want a bunch of apps I have installed because they are no longer useful. Same with User Data and Other Data. For example I have a bunch of gopro videos on my HD from a vacation in my "movies" folder. I've already edited the content and made a video. All I want is the final video. I don't need the 50GB of raw footage sitting on my internal drive. I will keep the Raw on my time machine and now a second copy on my bootable clone. If I use MA/SA I have to take those files in the restore because I do want my other movies. In time machine can't I open "movies" - select all folders except "Costa Rica GoPro"  and click restore?
B)
The question is really geared towards  apps. Is there a benefit to restoring apps by actually downloading new installers via the web/app store. Since those are clean installs too. My concern is that application restores via time machine or MA/SA may have those tiny bits of data that make the software not 100% since some of my apps were installed years ago and have undergone not only OSX updates but their own in app update process (fragmentation) Like firefox for example..... I cant even image how many times it's been updated in the last 4 years. Obviously clicking the apps box is really easy and I'd prefer it.
I may be over thinking it but I really only want to do this once. Since I will be spending a considerably large chunk of time I want the computer to be a efficient as possible.
A)
You can selectively restore from Time Machine as you state (into an brand new user account), but I think you will find that grabbing all the User data & then deleting the stuff you don't want is faster than pecking away and restoring items individually. Are you even aware where all the important files live (calendars, contacts etc). When it comes to Apps do you know where any required support files are stored?
Otherwise you need to dig into the hidden ~/Library for things like keychains, Mail settings, Safari history… not to mention the app DB's like iTunes, iPhoto etc.
B)
All or nothing is how MA works - this is especially true of apps. MA is actually too good at bringing old data over IMO - it brings too much, not too little.
You don't just get the .apps from /Applications. With MA's 'Applications' option you get App support files that may exist in any of the Libraries (Fonts, updaters, plugins, template data – basically all the junk you are running away from).
If you really want to restore a few apps from the TM copy or clone do so (provided these are 'drag installed' apps), but it is far better to get the latest release from the developer's site (not software aggregators). The App store makes it very quick to install your apps too. Apps that use packages may install support files elsewhere, so dragging the app from a backup is not enough to have it all.
Fragmentation in terms of files is not an issue - the OS deals with that itself anyway (defragging files as they are accessed). The actual issue is having too many ancient apps with frameworks, plugins, extensions, system level background jobs and other processes that interfere with the OS.
Clearly it is your own choice, I find it is fastest to clone the important stuff (just user data) then reinstall the handful of important apps. Apps like GrandPrespective or Whatsize make finding & purging large files easy. You may be surprised by how few apps you actually need - keep the machine lean to maximise performance.
If you want to see what is installed take a look at an Etrecheck report, no need to post it unless you want to, but it can indicate what you have laying around on disk.
http://etresoft.com/etrecheck