Re: Wiping Swap Partitions

[Jari Ruusu <jari.ruusu@pp.inet.fi>]

Sam Simpson wrote:
> I'm thinking of using the following on shutdown:
> 
> swapoff -a
> dd if=/dev/zero of=/dev/hda1 bs=1024k count=64
> sync
> mkswap /dev/hda1
> sync
> swapon -a
> 
> (after checking that hda1 is swap ;).  Any comments or improvements?

If you are using loop-AES, just set up encrypted swap like this:

First, run "swapoff -a" to turn off swap devices in your /etc/fstab file.  
Second, add "loop=/dev/loop?" and "encryption=AES128" options to swap lines
in your /etc/fstab file. Example:

 /dev/hda666   none   swap   sw,loop=/dev/loop6,encryption=AES128   0   0  
                                ^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^
Third, run "swapon -a" and "rm -rf /var/log/ksymoops" and you are done.

Running "swapon -a" will set up loop devices using random keys, run mkswap
on them, and enable encrypted swap on specified loop devices. Usually your
distro's startup scripts will run the "swapon -a" command so you don't need
to change your startup scripts at all. As expected, "swapoff -a" will tear
down such loop devices.

Regards,
Jari Ruusu <jari.ruusu@pp.inet.fi>

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