https://wiki.bwt.com.de/index.php?action=history&feed=atom&title=Encrypting_An_Existing_Partition 2026-05-13T20:46:56Z Revision history for this page on the wiki MediaWiki 1.43.0 https://wiki.bwt.com.de/index.php?title=Encrypting_An_Existing_Partition&diff=7&oldid=prev 2014-01-06T01:52:15Z

<p>1 revision</p> <p><b>New page</b></p><div>=Prep=<br /> <br /> While sing dd to blank the partition using /dev/zero is usually quick, using dd to fill a drive with random data using the cryptographically-secure /dev/urandom can take a long time. To wit, a Via 1.2GHz C7 7-watt single-core CPU would have taken 6&amp;frac12; days to fill a 500GB drive using /dev/urandom. An AMD 2.8GHz Anthlon II quad-core CPU took 4&amp;frac12; hours. You may wish to move the drive to a faster computer.<br /> <br /> #Comment-out appropriate entries in /etc/fstab<br /> #Shut down the computer the drive originated from.<br /> #Remove the drive.<br /> #Restart the computer the drive came from if you need it.<br /> #Power off the target computer the drive will be temporarily installed to.<br /> #Install the drive in the faster computer.<br /> #Boot into Linux on the faster computer.<br /> #Run &lt;code&gt;sudo fdisk -l&lt;/code&gt; to list the partition of all drives.<br /> <br /> Alternatively, you can just leave the drive where it&#039;s at and unmount the device.<br /> <br /> sudo umount [mount-point]<br /> <br /> =Wipe=<br /> <br /> Protect against data recovery by blanking the partition.&lt;br&gt;<br /> The extra ampersand at the end will allow the process to run in the background and spit out a process ID number.<br /> <br /> sudo dd if=/dev/zero of=/dev/sd[a-z][0-9] bs=1M &amp;<br /> <br /> The bigger the partition, the longer dd takes.&lt;br&gt;<br /> If you want to check the progress of the process at any time, issue this command<br /> <br /> sudo kill -USR1 [process-id]<br /> <br /> Protect agains physical hackery by filling the partition with random data.&lt;br&gt;<br /> This makes it tougher to tell which parts contain encrypted data and which do not.<br /> <br /> dd if=/dev/urandom of=/dev/sd[a-z][0-9] bs=1M &amp;<br /> <br /> =Crypt &amp; Format=<br /> <br /> Run this command to set up the encrypted partition:<br /> <br /> cryptsetup -y -c aes-cbc-essiv:sha256 luksFormat /dev/sd[a-z][0-9]<br /> <br /> Re-mount the encrypted partition:<br /> <br /> cryptsetup luksOpen /dev/sd[a-z][0-9] [name]<br /> <br /> Format the partition:<br /> <br /> mkfs -t [filesystem] /dev/mapper/[name]<br /> <br /> =Configuation=<br /> <br /> Edit /etc/crypttab and add an entry<br /> <br /> [name] UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx none luks<br /> <br /> Edit /etc/fstab and add an entry<br /> <br /> /dev/mapper/[name] [mount-point] defaults 0 2<br /> <br /> Update the initrd image.<br /> <br /> sudo update-initramfs -u</div>

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