[Macworld]

Post your comments for Partition your hard drive with data still on it here

[TheAndrewLoeb]

I was just looking into this recently because I have a drive I was using with an old Windows PC that I want to now use for my MacBook. Ideally, I'd like to keep the Windows data (backups, some photos, etc.) and use it with the PC, which is still running, on occasion. When I tried to partition the drive with the method explained above, Disk Utility told me that because the disk is NTFS, it cannot be partitioned. Are there ways around this, or do I need to migrate everything to another drive, reformat the whole thing, partition and then move all the date back again?

[dudemac]

TheAndrewLoeb, on 05 January 2012 - 06:46 AM, said:

I was just looking into this recently because I have a drive I was using with an old Windows PC that I want to now use for my MacBook. Ideally, I'd like to keep the Windows data (backups, some photos, etc.) and use it with the PC, which is still running, on occasion. When I tried to partition the drive with the method explained above, Disk Utility told me that because the disk is NTFS, it cannot be partitioned. Are there ways around this, or do I need to migrate everything to another drive, reformat the whole thing, partition and then move all the date back again?

I would use Gparted to shrink your ntfs partition, then you can format the now empty space to whatever you like. This should not affect your windows partition or your data on the ntfs partition.
You can get it here. GParted

[zarmanto]

TheAndrewLoeb, on 05 January 2012 - 06:46 AM, said:

... When I tried to partition the drive with the method explained above, Disk Utility told me that because the disk is NTFS, it cannot be partitioned. Are there ways around this...?

Apple hasn't incorporated very extensive support for NTFS in Mac OS, probably due to licensing issues. However, there are several third-party tools (both free and commercial) which might be able to help you out with your requirement -- just be aware that partitioning always carries some level of risk, even if you're using a tool which specifically claims to perform "non-destructive" partitioning. So always, always, always perform a backup of your data before repartitioning the drive.

Now, with that out of the way... One good listing of such tools can be found here: http://guides.macrum..._Camp_Partition

[leicaman]

Is no one going to point out that repartitioning a drive is dangerous at best? Never do this procedure without backing up the drive first, if the data is at all important to you.

[n4hhe]

While it is possible to repartition with data present, its not without risk.

In ancient times on PCs the popularity of utilities such as Partition Magic and/or Norton's Ghost was exactly that of being able to resize and move partitions containing data.

[n4hhe]

TheAndrewLoeb, on 05 January 2012 - 06:46 AM, said:

I was just looking into this recently because I have a drive I was using with an old Windows PC that I want to now use for my MacBook. Ideally, I'd like to keep the Windows data (backups, some photos, etc.) and use it with the PC, which is still running, on occasion. When I tried to partition the drive with the method explained above, Disk Utility told me that because the disk is NTFS, it cannot be partitioned. Are there ways around this, or do I need to migrate everything to another drive, reformat the whole thing, partition and then move all the date back again?

The problem of sizing an occupied partition requires intimate knowledge of the file structure. If making the filesystem smaller you have to be able to move files or the portions of files which are outside the new smaller partition and you have to fixup all the other references. Its not surprising Apple declines to attempt this for NTFS.

[Chris Breen]

leicaman, on 05 January 2012 - 07:44 AM, said:

Is no one going to point out that repartitioning a drive is dangerous at best? Never do this procedure without backing up the drive first, if the data is at all important to you.

That's certainly the conventional wisdom, but how up-to-date is it? Anyone here actually lost data performing this procedure on a Mac-formatted hard drive? Part of the point being, if this is an inherently dangerous thing to do, why would Apple continue to offer this feature?

[bastion]

I find myself wondering *why* Mr. Riley wants to partition his drive. While there is value to it in certain circumstances, for most people it has very little benefit and can carry along some significant drawbacks.

Because of the rarity of actual value in this task, to me this is one of those cases where the answer to "How do I ..." starts with "What are you really trying to do?"

This post has been edited by bastion: 05 January 2012 - 08:07 AM

[Chris Breen]

bastion, on 05 January 2012 - 08:06 AM, said:

I find myself wondering *why* Mr. Riley wants to partition his drive. While there is value to it in certain circumstances, for most people it has very little benefit and can carry along some significant drawbacks.

Because of the rarity of actual value in this task, to me this is one of those cases where the answer to "How do I ..." starts with "What are you really trying to do?"

Oh, I dunno. I keep a partitioned drive so I can boot into either Snow Leopard or Lion. Particulalrly handy when you have multiple Macs, some of which can't boot Lion.

[TheAndrewLoeb]

Thanks for the recommendations. I'll read up on some of the tools suggested. I suppose I didn't make it explicit, but I would obviously backup the existing drive as is just in case. I'll let you know if anything explodes.

[MisterPeabody]

Chris Breen, on 05 January 2012 - 08:13 AM, said:

bastion, on 05 January 2012 - 08:06 AM, said:

I find myself wondering *why* Mr. Riley wants to partition his drive. While there is value to it in certain circumstances, for most people it has very little benefit and can carry along some significant drawbacks.

Because of the rarity of actual value in this task, to me this is one of those cases where the answer to "How do I ..." starts with "What are you really trying to do?"

Oh, I dunno. I keep a partitioned drive so I can boot into either Snow Leopard or Lion. Particulalrly handy when you have multiple Macs, some of which can't boot Lion.

Yours is one of those "certain circumstances" bastion mentioned: a boot drive. The original commenter has 250GB worth of external data. Several options are available for housing it separately. Whatever the optimum solution, the uncertainty reinforces the validity of bastion's question.

[zarmanto]

Chris Breen, on 05 January 2012 - 07:55 AM, said:

That's certainly the conventional wisdom, but how up-to-date is it? ...

All due respect, Chris -- but did I just read the correctly?... is a writer for a popular computer-centric magazine actually downplaying the importance of backing up data prior to messing around with the partition tables of a hard drive? Because if so, then it sounds to me like you've developed an awfully idealistic view of the world -- Mac experience notwithstanding.

Chris Breen, on 05 January 2012 - 07:55 AM, said:

... if this is an inherently dangerous thing to do, why would Apple continue to offer this feature?

Because tools which are inherently dangerous are still tools which can have value when used with care. Do we stop stores from selling steak knives, because buyers might cut themselves or someone else?

[Chris Breen]

zarmanto, on 05 January 2012 - 09:55 AM, said:

All due respect, Chris -- but did I just read the correctly?

I certainly hope so. So many of us are accustomed to parroting conventional wisdom without really questioning the accuracy -- in today's world -- of that wisdom. That's why I asked "Who here has lost data doing this?" To claim that this process is "dangerous at best" without any supporting evidence or experience seems hollow to me. Of course something could go wrong, just as something could go wrong when you move your laptop when it's writing data to the drive. And yes, one should always have a backup of their data.

But, the point is, HOW dangerous is it? Dangerous enough to only attempt with a full backup? To sacrifice a goat? To wear oven mitts?