I have an external HD (western digital) with 1Tb. I use Linux but I wanted to reserve a cross platform partition on the disk. I decided to create two partitions and used the "disks" application to do it. I created one partition with the LUKS (version 1) encryption and the other one, cross platform, in NTFS filesystem. Things work fine on my OS but when I try to use the disk (the cross platform partition) on both windows and mac the device is not recognized. What could it be?

Next, output of "sfdisk -l /dev/sdb":

Disk /dev/sdb: 121600 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/sdb1          0+  36473-  36473- 292968750   83  Linux
/dev/sdb2      36473+ 121600-  85128- 683789062+  83  Linux
/dev/sdb3          0       -       0          0    0  Empty
/dev/sdb4          0       -       0          0    0  Empty

Next, outputs of blkid /dev/sdb1 and blkid /dev/sdb2

/dev/sdb1: UUID="e3e7453c-451c-4608-8c39-55ff3b21c3a7" TYPE="crypto_LUKS"

/dev/sdb2: LABEL="Media" UUID="2D2CF22A62C95135" TYPE="ntfs"

  • NO idea what your problem, but I find it is usually easier to setup the NTFS volume under Windows, leave free space. Then partition the free space within your alternate operating systems.
    – Zoredache
    Nov 6, 2013 at 0:54
  • Just for our edificiation, it might be useful if you posted the output of sfdisk -l /dev/sdN where /dev/sdN is the actual device name for your portable drive.
    – Zoredache
    Nov 6, 2013 at 0:56
  • I just did it..
    – PDRX
    Nov 6, 2013 at 1:28
  • If you did format one of those partitions as NTFS, then did it wrong. It seems you may have set the wrong filesystem type on the partition. What do you see if you run blkid /dev/sdb1 /dev/sdb2? If you have any data on the drive you probably should migrate it off. Delete the parition meant for NTFS, and just create the NTFS volume under Windows.
    – Zoredache
    Nov 6, 2013 at 7:06
  • I added the outputs of blkid /dev/sdb1 and blkid /dev/sdb2. you can see the ntfs
    – PDRX
    Nov 6, 2013 at 10:12

3 Answers 3


Your second partition may be formatted as NTFS, but its type in the MBR partition is still set to 83 (=Linux). You will have to change the type to NTFS using a partitioning tool like fdisk or gparted.

(With a bit of luck you won't have to re-format.)

Please note that OSX will not WRITE to NTFS, unless you buy extra software. Reading will work out of the box.

You could also use ExFAT which is writable by all 3 operating systems, but in that case it is very much recommended to FORMAT the partition on a Windows system. It seems that Windows sometimes doesn't handle ExFat properly if it was formatted in OSX or Linux.

  • 1
    To change the partition type code, use fdisk and its t command. You should change the ID code on the NTFS volume (presumably /dev/sdb2) from 83 to 07, then use the w command to save your changes.
    – Rod Smith
    Nov 6, 2013 at 18:00
  • @RodSmith Thank you for the addition. I didn't have a Linux system handy when I wrote the answer, so I couldn't be sure of the exact commands. (Well, t and w I knew, but the 07 I wasn't sure about. I don't do NTFS partitions from Linux that often.)
    – Tonny
    Nov 6, 2013 at 19:39

Partitions sdb1 and sdb2 are Linux partitions, therefore only fully usable on Linux. So I'm guessing you want sdb3 and/or sdb4 for NTFS, so set it to the appropriate type on sfdisk, fdisk, etc, and then try accessing it on Windows. It will prompt for a format.


Your disk does not have any NTFS partition. The code-word Linux under the System heading indicates one of the standard Linux partitions, ext2, ext3, ext4.

Nor can you use partitions sdb3 and sdb4, which have zero size. Notice that your disk is made of 121600 cylinders, that your sdb1 partition begins at 0 and ends at the 36473th cylinder, while your sdb2 partition begins at 36473 and ends at 121600th cylinder. Thus your disk is completely allocated to these two partitions.

However, what you can do is to use one of the free Windows utilities to access Linux partitions. Windows does not support etx2/3/4 natively, but there are third-party applications that will allow you to use your disk without problems. I know at least three such applications, pick the one that suits you best:

1) DiskInternals Linux reader

2) Ext2fsd

3) Ext2read

Careful, though: these are readers, which means they allow to read data, but not to write to disk. The only one which should be able to write to disk is Ext2fsd, but it does not support journaling, which means that, if you write to it in Windows, and then re-mount in Linux, all sorts of problems might arise. I have never used it to write, I am worried of what it might do to my data, and suggest you may wish to stay away from this feature.

Alternatively, there is Paragon ExtFS for Windows, which is commercial software provided free of charge for personal use. It claims explicitly to be able to write to disk:

Import/Export files and folders from/to Ext partitions. For example, if the hard drive is taken from NAS storage and you need to open a Linux partition and copy from it or place a new file there, Paragon ExtFS for Windows eliminates the need to install the hard drive or configure it for network access. Simply connect a hard drive via the eSATA connector or USB-to-SATA adapter to the PC and access your files.

I have highlighted the relevant parts. I have never used, so I cannot vouch for it.

As for Mac, you can read this enlightening answer from this very same site for solutions.

There is lastly a solution which is viable if Windows, Linux and Mac are running on different machines: attach your disk to the Linux machine, and share the folders. You can read here about a guy who did just that.

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