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I'm using Mac OS X more and more, having come from Windows XP. Since Win9x I've been partitioning my drives into C and D partitions. C is the Systems/Programs partition, D is for Data. The reasons being that it is easier to back up data and when the eventual re-install of Windows is necessary, I just format C and do a clean install.

When I upgraded the hard drive in my mac mini, I did the same but came across some snags. Mac OS X seems to be very home directory oriented, even more so than Windows with My Documents. So by default, programs try to save to the home directory and so the System partition. Same with the desktop. (I used powertoys on XP, to move My Documents, Desktop etc to the D drive)

So, should I just forget about creating separate partitions with Mac OS X? I know there may be ways to move the home directory involving creating links, but is it advisable?

Thanks in advance!

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migrated from Oct 5 '09 at 7:30

This question came from our site for system and network administrators.

I was thinking of doing this - the question becomes even more important if you can dual boot using SSD for the OS and normal HD for the apps/data. Backup requirements for OS/ Apps/ Data are somewhat different. Does Time Machine work across partitions? – alimack Mar 3 '10 at 11:23

There is certainly no problem with creating another partition for your user data (home folder). In fact, this is a very common thing to do on *nix based operating systems. To do this, just follow Chealion's instructions:

Go to the Accounts Preference Pane in System Preferences, right click on your user and choose Advanced Options… and move your home directory to another partition, volume or even network share for more advanced users.

Whether it is advisable or not is a completely different story, especially given the recent improvements in the OS X install process. These days, if you want to reinstall OS X Snow Leopard, you just whack the DVD in and follow the steps. It will restore all the system components, while leaving all your user data and applications in tack. I believe it archives all your user data, installs the new system, then replaces your user data back into it's rightful home.

But still, backing up all your data on OS X is as simple as copying your Home directory, which shouldn't take long to do and restore. Do you really need to go through the hassle of partitioning (keeping in mind that you shouldn't not be resizing partitions willy-nilly) if it is only for a once-off occurrence (which is now mitigated because of the Snow Leopard install process)?

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There's no need to create links to move your home directory - you can go to the Accounts Preference Pane in System Preferences, right click on your user and choose "Advanced Options..." and move your home directory to another partition, volume or even network share for more advanced users.

That said partitioning is completely up to you but for separating the system and the data you aren't really going to find a performance improvement unless they are on separate disks. By default an Archive and Install won't touch your User directory at all and only replace the system files. Mac OS X 10.6 will automatically do an archive and install over top of an existing Mac OS X 10.6 installation.

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Since Lion, I've partitioned a few hundred Gigs off, to be used for Time Machine Backups. While this will not protect me from a hardware failure, it has saved me from a boot partition corruption that happened during a panic while shutting down, and gives me several other backup benefits, such as restoring older versions of applications or documents, or doing an system restore if I suspect an application has destabilized my system. However, I haven't really found it useful to partition portions of the standard filesystem in either MacOS nor Linux/FreeBSD... In fact, I've found that to cause more trouble in the long run, when one partition filled up whilst there was ample space available in another.

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