MacOS – MacBook Air with small SSD, BootCamp, Windows 7. Can I use an external hard disk for dual boot

bootcampdisk-spacemacbook promacos

I'd like to setup a dual boot onto my MacBookAir 128GB, with Microsoft Windows 7 Ultimate in BootCamp. However, I'm already close to the 128GB limit (games + CS suite + Eclipse + XCode + a lot of Web development tools).
Therefore, it would be ideal for me if I could use the same HDD I will run my Time Machine saves on… when it's finally delivered!
The question is therefore: is it reasonnable to create a dual partition on that and run Windows 7 from the first one?

Would MacBook Air tolerate launching Windows 7 from an external disk?
Is there a risk (save for USB deconnection) that HDD might not be a working solution, as in too much lag? Could (eventually) a Thunderbolt external SSD be an acceptable workaround?

Best Answer

Since you must boot Windows 7 from the internal SSD, and since you also want to run Mac OS X from the same volume, I recommend that you concentrate on cleaning out your existing Mac OS X system and freeing up as much disk space as possible.

You should research on how to make the smallest Windows installation possible, so you can create the smallest BootCamp partition possible. From what I can see, you could do with as little as 12GB if you are meticulous.

For instance, once Windows is installed, you can permanently disable hyberfil.sys and reduce or limit the size of pagefile.sys, and this will save you many GB.

I would also look into the differences between the size of the installation in Windows 7 32-bit versus 64-bit, and see if Windows 7 Ultimate takes up a great deal more space than Windows 7 Professional or Windows 7 Home Premium (I suspect it does). You will want to refrain from installing any features of Windows that you decide you don't need, and you will want to make sure that you don't install any Windows applications that you don't absolutely need.

Here are some links to discussions I found. I cannot vouch for any of these methods.

Reference One at Tom's Hardware

Reference Two at Microsoft TechNet

There is a utility for reducing the size of a Windows installation before you actually install it. It is called vLite. It is not exactly kosher and has its detractors. I have no personal experience with it. To use it, you need a working Windows system to configure a special custom installer DVD that vLite helps you create.

Reference Three, a discussion of the benefits of vLite and how many GB you can save.

Regardless, you are going to have to wipe the internal drive on your MacBook Air and try different partitioning schemes, so you must have yet another a large external hard drive for making backups of the system you already have. Use Carbon Copy Cloner or SuperDuper!.

On the Mac side, there is a lot you can do to reduce the size of your Mac OS X partition by removing components of Lion that you do not need.

Make a complete backup disk image first before you start deleting things!

Similarly, it is possible to permanently delete the Mac OS X sleepimage file, which will save you the same amount of disk space as the amount of RAM that you have.

Information about sleepimage file

SmartSleep utility for controlling the sleepimage file

Delete the contents of /Library/Printers, which could be several GB, and when you restart your Mac, Lion will prompt you to download only the drivers for the printers you actually use.

You should completely remove any applications in iLife that you don't use, including all their support files in the /Library/ folder. iDVD, GarageBand and iPhoto have many GB of support files, themes, templates, and audio files, and if you don't use any one of those programs, you can clean out that disk space.

Utilities such as MonoLingual can remove more than 1GB from your Mac OS X installation by removing all the files for languages (Spanish, French, German, etc.) that you will not use.

Use OmniDiskSweeper or WhatSize to examine your Mac OS X installation and look for user documents that you feel safe in archiving and removing, or deleting.

There is an analogous freeware tool for Windows called WinDirStat.

Related Solutions

Use bootcamp without reformatting the hard drive

Boot Camp doesn't require you to reformat your drive. HFS+ partitions can be live-resized by the Boot Camp Assistant or the Disk Utility without going through the trouble of erasing everything. No file on your Mac OS partition will be affected.

There is, however, the case where you've had your computer for long and Mac OS has written files all across your drive. In this case, you will need to defragment your drive, in order to put all your files in a nice contiguous space on your hard drive, so that all the remaining space is contiguous too and a partition can be made there. As far as I know, iDefrag can do this for about $15. (Disclaimer: I never did it and can't guarantee it will work. But it should. Can someone confirm?)

The other way, if you have an external drive, is to copy all your files to this external drive using a software like Carbon Copy Cloner (free), reformat your drive, then copy them all back to your drive. Everything should be like before and you'll have no hassle except the time required to copy back and forth (your programs and your serial numbers and the such will be intact).

MacBook Air dual boot Lion+10.6

Yes - it's trivial to partition and takes a negligible amount of space away from the drive for the second partition's overhead.

Since that model is supported on Snow Leopard - the installer will run happily to install to any partition that's larger than 6G.

Since the mac stores the default boot volume in NVRAM - there's really no delay in booting unless you hold the option key to get the boot manager and ignore the stored default.

Lion and BootCamp can be a little fussy, but most times you can just resize your current OS to make room for the new one, make a new partition and run the installer.

Windows doesn't like more than 3 partitions on the drive and the BootCamp assistant doesn't want to deal with two mac partitions, so you have to know enough about Disk Utility to do that setup by hand. For SL + Lion - you'll end up with two large partitions and a small Recovery HD at the end of the drive

Here's what one of my macs with a copy of Lion and Lion server looks like. You'll have one less Recovery HD with Snow Leopard.

mac:~ mike$ diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *160.0 GB   disk0
   1:                        EFI                         209.7 MB   disk0s1
   2:                  Apple_HFS mac                     94.3 GB    disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
   4:                  Apple_HFS server                  64.2 GB    disk0s4
   5:                 Apple_Boot Recovery HD             650.0 MB   disk0s5

Best Answer

Related Solutions

Use bootcamp without reformatting the hard drive

MacBook Air dual boot Lion+10.6

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