Are there any known solutions to manually or automatically expand a TrueCrypt volume on Mac OS?


You cannot expand it once it's created. Create a new volume of the size you now wish to have, mount both the old and new ones, and copy the files from the old volume to the new one. Then unmount the old volume and delete its file container.

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    Thanks for the contribution Alexander. However, I found that you could use extcv (extcv.sourgeforge.net) to resize a truecrypt volume using a win* box. Then you can use 'diskutil' on MacOS to expand the HFS+ partition on the truecrypt volume. – joet3ch Mar 13 '10 at 22:59
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    Why would you want to do something to a TrueCrypt volume which is not supported by TrueCrypt itself? Does the integrity of your data not matter to you? – Alex Mar 14 '10 at 1:34
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    Have you viewed extcv's source code? The author is utilizing the TrueCrypt libraries. Hopefully this added feature will make it into the TrueCrypt project core soon. Until then, this is a welcomed solution to an otherwise archaic method of manually copying the volume contents. – joet3ch Mar 14 '10 at 2:44
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    @joet3ch: I was not aware of that, no. While the code may be there, it's a fairly safe assumption that if the functionality was there it would be exposed in the UI were it mature enough for widespread use. The contents-copying method is archaic, yes, but guaranteed to work and guarantees the integrity of the data, TrueCrypt container, and filesystem more than any other approach -- and ultimately, those three matter to me more than anything else (and probably to others -- that tends to be data one values above all else). – Alex Mar 14 '10 at 7:55
  • Now that TrueCrypt is no longer actively maintained, there are two forks. One of them, VeraCrypt, now supports expansion of volumes. – user149408 Oct 12 '17 at 11:36

This is possible if you have access to a win* box. Run extcv (from http://extcv.sourceforge.net) which will resize the TrueCrypt volume. Then you can use diskutil resizeVolume <vol_id> <size> on Mac OS to expand the filesystem.

This works great :) Here is a simple tutorial:


  • Note that this is a old version, which supports only TC 7.0a. If you have TC 7.1a, use the last version at bitbucket.org/j0s3f/extcv. The authors recommend switching over to VeraCrypt, which includes this functionality natively. – user149408 Oct 11 '17 at 16:17
  • Another, more generic tutorial (now archived) is at web.archive.org/web/20130115031311/http://wiki.schlimmchen.de/… – user149408 Jun 22 '18 at 13:15
  • In my case, with an NTFS volume, extcv (the version from bitbucket) would expand both the container and the file system inside, no further actions necessary. Not sure if this works the same way for all file systems, though. – user149408 Jun 22 '18 at 14:14

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