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I would like to mount an ext4 truecrypt drive with --fs-options but it doesn't work. Also I created a FAT partition and the following command is working. What is the alternative command if my partition is ext3/ext4?

sudo truecrypt --mount /media/vulturus_data/test3 /media/true  --fs-options="users,uid=115,gid=123,fmask=0113,dmask=0002" 
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up vote 4 down vote accepted

Those filesystem options are available for FAT because FAT does not support file permissions. Ext2/ext3/ext4 filesystems on the other hand do support file permissions. After mounting the container on /media/true:

  • Change ownership and group membership (corresponds to uid=115,gid=123):

    sudo chown -R 115:123 /media/true
  • fmask=0113 removes the executable bit from all files and write bit from the others. This is the default, so you should not need to change it. Anyway, the command to do so is:

    sudo find /media/true -type f -exec chmod a-x,o-w {} \;
  • dmask=0002 is supposed to remove the write bit from directories for the world. This bit is usually not set. To remove it in case it is set:

    sudo find /media/true -type d -exec chmod o-w {} \;
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make sure there's a directory under /media/ called true

run the following commands to make sure

sudo mkdir /media/true
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The directory is there, I created that. – Kicsi Mano Feb 7 '12 at 16:30

Probably --fs-options="..." must be put before the volume path and mountpoint:

sudo truecrypt --mount --fs-options="users,uid=115,gid=123,fmask=0113,dmask=0002" /media/vulturus_data/test3 /media/true

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I tried in this way also without success – Kicsi Mano Feb 7 '12 at 16:37

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