Become a MacRumors Supporter for $25/year with no ads, private forums, and more!


macrumors newbie
Original poster
May 12, 2013
Hey guys, today i tried the developer preview of Mavericks and it was awesome. Unfortunately it messed up my Windows 7 bootcamp, probably becaused i repartitioned the hard drive to install Mavericks to an extra partition. I've used it for an hour and i was impressed moslty disregarding a few bugs (the battery icon showed 10 hours remaining when on 92% whereas before it was on about 5!). Now i would like to install it over my Mountain Lion and use it as a main OS but i'm not sure how to backup my data as i don't have an exeternal hard. Is there a way to back it up on to a bootcamp partition? I mostly care about pictures, music, photos, documents etc, and i only want to install it over my Mountain Lion erasing everything so it can work better. Tnx in advance.
Nov 28, 2010
Get an external HDD or even 32 or 64 GB USB flash memory thumb drive if that would suffice. A backup is ALWAYS stored on another physical disk than the original data, thus if the installation frells up, especially since it is a developer preview and you got your hands on it being a developer and all, your "backup" might be frelled too.


macrumors 68020
Jun 15, 2012
Get an external drive and set up Time Machine. You can't backup to another partition of the same drive: if the drive fails, you will lose both partitions.

You need a backup if you value your files.

A default installation of a new OS will install in place of the old OS, leaving your user data, settings and apps in place. However, you need a backup, just in case!

Secondly, that battery indicator may not be a bug. I'm definitely getting almost twice the battery life on my old MacBook.


macrumors newbie
Original poster
May 12, 2013
How dangerous is it really?

Well i don't really have anything extra sensitive or important to conserve but i will look into external hards anyway. I wanted to know if there is a possibility that something could go so wrong on this beta that i could get a major failure or anything serious? I'm not sure about the preceeding previews (10.8,7...) has there been some major crashes or anything? From what i've seen and read about Mavericks beta it's a big plus and seems solid. Also will it underperform if i just install it over my 10.8 (i don't have much data, about 100gb is taken)?


macrumors G4
Jun 30, 2007
...I mostly care about pictures, music, photos, documents etc,....
Well i don't really have anything...important to conserve...
Sounds like a contradiction. So you have photos and documents you care about but they are not important if you lose them forever?:confused: Just do a search of people who have had a HD failure without a backup. I've been there (several yeas in the past) and it's a truly helpless and sickening feeling knowing all your 10001001 are on the HD but no way to get to them.


macrumors newbie
Original poster
May 12, 2013

No i meant that pics, music and documents are the only things that i have that i can lose (no important apps) but even those aren't critical to me in any way or work related or even too many actually. I have them all on my iphone as well so not really much to lose. I forgot to ask if someone knew why my bootcamp windows partition failed (no bootable device error) after i repartition my MAC hard so that i could install the 10.9 and is there a chance of it happening again if i should reinstall it over my current OS.


macrumors regular
Jun 3, 2013
Time Machine is the easiest and best way to back up a Mac, IMO. As far as what you are trying to do, you can achieve this by using Migration Assistant from within Mavericks and it will cleanly transfer all your user data and documents over to your Mavericks installation. After this, you can delete your Mountain Lion partition and resize the drive so you only have 2 remaining partitions, Bootcamp and Mavericks. This may solve your Bootcamp issues too, but I would be ready to consider that a loss. I did the same thing on my Mac and it lost the ability to boot the Bootcamp partition for some reason. Luckily, I had a backup of my Windows installation so I just deleted the partition, resized the drive, ran Bootcamp assistant and it is now all working peachy.

I have to say I am impressed at the level of refinement that OS X has in regards to such situations.


macrumors member
Aug 13, 2009
Try SuperDuper! It creates a bootable backup of your Mac, you don't even have to perform a restore. So if anything goes wrong you simply plug in your USB HDD and boot from that. It's free too, $29 gets you the ability to do incremental backups.

Time Machine is fantastic though, and backups in any form are essential.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.