Can't use external harddrive on MBP

[total90]

So i bought this new 500GB external HD but whenever i tried to put my files in it from my mac it wont allow me and say, "This item could not be moved because [harddrive] cannot be modified."
however if i connect it to my windows it works fine.
i've searched online but i dont know what partitioning exactly mean so i came here for help.
thanks!

P.S just one stupid question, why would a 500GB HD has less capacity such as 470 or so; and sometimes 8GB USB will only have 7.5 G etc.

 

[MacDawg]

You drive is likely formatted as NTFS and is read only for Mac OSX and not read/write

Check out the guide on File Systems

NTFS
This is the current preferred file system of Windows (beginning predominance circa Windows NT 4.0 and Windows 2000, and including Windows XP). Most Windows systems use principle partitions with this file system. This is a journalled file system with good support for large files. It should be noted that it does NOT support POSIX permissions or ownership. Mac OS X has read only support for this format. It has no capabilities to write to an NTFS drive. Windows has complete read/write capabilities for this format.

P.S just one stupid question, why would a 500GB HD has less capacity such as 470 or so; and sometimes 8GB USB will only have 7.5 G etc.

Check out the Guide here at MR: Hard Drive Size Discrepancy

Hard Drive Size Discrepancy

Why does my new 500 GB hard drive report it only has 465 GB? Have I been ripped off?

No, you haven't been ripped off. 500 GB = 465 GB, strange as it seems.

The reason is that computers count a "kilo" something as 1024 (binary 2^10) while the rest of the world count a "kilo" as 1000 (decimal 10^3). A 'mega' in computer binary system is 1024 x 1024 = 1,048,576 (rather than decimal 1,000,000), and a 'giga' is 1024 x 1024 x 1024 = 1,073,741,824 rather than decimal 1,000,000,000

This creates a discrepancy of approximately 7% between the number of GB the computer reports, and what is advertised as the drive's capacity in GB. It is important to note that there is no difference in the number of actual bytes of storage - it is only a difference in reporting when the binary 'giga' terminology is used.

A 500 GB hard drive has about 500,000,000,000 bytes (it is never exact, commonly a drive is designed to have more bytes, to allow for a certain number of defective sectors to be mapped out). When counted on the computer, 500 Gb (decimal) = 500 billion bytes = 465.66 GB (binary).

Some propose using a different term, gibibyte (GiB) for the binary figure, however that is unlikely to catch on in the marketplace.

Woof, Woof - Dawg

 

[GoCubsGo]

You need to format your drive for OSX. NTFS will limit the file size that you can transfer, as such, you need to format it for a mac.

You can format and partition at the same time:


Mac OS X 10.5 with no changes to the partition scheme

In the Applications folder, open Utilities, and then double-click Disk Utility.

In the left column, click the drive you would like to initialize or partition.

To the right, click the Partition tab.

The box beneath "Volume Scheme:" (which should be set to Current) represents your hard disk, where occupied space is shaded. With the handle at the bottom-right of each partition, you can resize the partition by dragging the handle up or down. To add or remove partitions, click the + (plus sign) or - (minus sign) beneath the box. You can assign each partition its own name and file system type.

When you finish making changes, click Apply
Mac OS X 10.4 and earlier, or 10.5 with changes to the partition scheme

To partition your startup disk, insert a Mac OS X install disc in your computer, and then restart the computer while holding down the c key. When you see the gray Apple, release the c key. Follow the instructions until you see a menu bar at the top of the screen, and then from the Utilities menu, select Disk Utility.

To partition disks other than your startup disk:

In the Applications folder, open Utilities, and then double-click Disk Utility.

In the left column, click the drive you would like to initialize or partition.

To the right, click the Partition tab.

In the drop-down menu under "Volume Scheme:", choose the number of partitions you want to create during the initializing process. For a basic installation of Mac OS X, you need at least one partition.

After you've chosen the number of partitions you want, you can adjust their sizes by dragging the handles that represent the partition borders.

Click each of the partitions to adjust its properties. Under "Volume Information", choose the file system you would like to use. You should usually use Mac OS Extended (Journaled). If you need to access the partition from Windows computers, however, choose MS-DOS.

Click Options... to change the partition scheme. You may need to change this if the disk is meant to be used with Windows computers, or as a startup disk for a Mac with a different architecture. Intel Macs require the GUID Partition Table for their startup disks, while PowerPC Macs use Apple Partition Map. If you need to use the disk with Windows, particularly as a startup disk, choose Master Boot Record. After selecting a scheme, click OK.

When you finish making changes, click Apply or Partition.

 

[total90]

You need to format your drive for OSX. NTFS will limit the file size that you can transfer, as such, you need to format it for a mac.

You can format and partition at the same time:


In the Applications folder, open Utilities, and then double-click Disk Utility.

In the left column, click the drive you would like to initialize or partition.

What exactly is partition? divide my HD into parts?

 

[old-wiz]

NTFS will limit the file size that you can transfer
..
.

NTFS does not limit file size; you're thinking of FAT - FAT 32 limits to 4 GB, FAT16 to 2GB. NTFS is only limited by the volume.

 

[i.shaun]

There are programs that allow you to write to NTFS from OS X, and is probably the most secure option to read/write from windows and OS X.


There is a program for Windows that can read/write to HFS+ (OS X format) but it's far more expensive. The Mac options can even be free but I forget what the program is called.


I went and paid for NTFS for mac, but that's alright. It works well enough.