How Do I Partition an External HD?

I got an external hard drive with a backup image. I want to make a partition on it without formatting it and without erasing this backup image. How can I do this?

 

you need something like mini tool partition wizard. First resize original, I assume full size partition to something smaller and then create new partition in empty space. it should work fine but nothing is 100%.

 

Do it like you would with any normal hard drive. If the drive is fragmented, then the built in Windows tool will not work, but if you have the free space you need at the end of the drive, Window's disk management tool will do the job. Otherwise, gparted would work.

 

And make sure you have a backup of your data before you do it. Because *you never know*

 

I'm assuming this drive is a Windows image (with tons of hidden files, dependencies, boot configuration, etc on the disk), where you cannot just copy contents from one location to another. The most direct way to do this is to use a partition resizing tool like GParted. GParted is a free tool, that lets you create bootable USB or disc media. It's pretty straightforward on how it works... just drag a slider to shrink one of the partitions on the drive. When that's done, go into Windows and create a new partition in that empty space you just freed up.

If this ISN'T a Windows image, and is just a bunch of files that you CAN freely copy from one location to another, then you'd actually be better off just copying data off of that drive, deleting / recreating partitions on that drive, and then re-copying the contents back on it. Using a tool like Gparted for content that is easily copied from one location to another is a bigger hassle than it's worth. It's slow, and carries a pretty decent risk of corrupting your data or making the drive unreadable if anything goes wrong. It's faster and safer to just use the copy-off-then-copy-back-on method I described.

Whatever you do, definitely create backups of whatever data you're trying to preserve. And I'm not just saying that as the typical "backup your data" blanket statement that you always hear. When you're dealing with creating / deleting / resizing partitions, you're engaging in an activity that has a high risk of losing your data. If ANY little thing goes wrong, there's a pretty good chance that your data will be lost. And the list of little things that could possibly go wrong are pretty extensive... bad sectors on the drive, obscure incompatibility between chipsets, quirky behaviors of USB-to-SATA bridge controllers, power loss, accidentally unplugging the USB cable during the operation, non-standard boot configurations or drive partition configurations, etc. Drive partitioning software works fine in well-tested and verified operating environments. But if you've never done a partition resizing using the specific hardware and software configuration, then you won't know if anything will go wrong until it actually DOES go wrong, and takes your data with it.

 

If the disk doesn't have NTFS filesystem and you have access to a Mac computer, the built-in Mac Disk Utility app works and is amazingly easy for partitioning disks. You'll know pretty soon if you can't partition it with the utility because the little 'plus icon' in the partition section of Disk Utility will not work. I've done it so many times and have never had any trouble. To be honest it might even work with NTFS to simply add a partition but OSX always struggles with NTFS format (Unless Paragon NTFS has been installed...).

Just throwing it out as a suggestion so consider the other options posted too - it does work well and it's easy but it also requires a Mac computer. Do yourself a huge favor and backup that image first - I've never had any problems but I also don't want to read a "I did what you said and now my disk is broken and zombies ate my mother in law" post in reply! .

 

..mnneeh. Actually, when you're not dealing with a "live" windows system partition that has been booted before, resizing partitions will usually work just fine, even with Fat32 and ntfs. Where you get into trouble is either when all the cached files are invalidated and the system is unable to recover it on the subsequent boot (which happens), or if you somehow wipe the partition table (in which case you're screwed anyway, and no system can recover this). Other than that, as long as you're not simply writing new partition information without copying the content (i.e., just hack away at the partition table and writing it without validating the contents, and then rewriting or overwriting a new partition over that data afterwards, etc..), it's extremely rare that the data actually is lost. But I'm a bit curious about why this really is an option in the first place - why the "image" has to be resized at all. I would sort of have assumed that we were talking about a system-partition with a bootable image, like a recovery partition or something of that sort. And this should just be a partition at a specific size on beforehand.

So if we're not talking about that, we're probably getting a bit ahead of things here, and what really should have been done first was to partition the external drive with gpt, have whatever bootable install media was available put in one partition, have that marked as primary, and then had some /efi/boot/ files copied in that partition so the system can boot from there, and so on. Then just have the rest of the space as another partition. There are a lot of neat tools out there that will help with copying the efi-boot files and extracting those so you don't have to worry about missing some files, btw..

 

I have a 2tb WD element and did do anything as partitioning it. I have my laptop images stored on there without any problems the way it is a single 2tb drive.