External USB Drives in Linux
Adding external USB drives in Linux is easy. Etch uses hotplug to detect it. Using dmesg you can find out what mountpoint it is (Linux creates a SCSI device to mount to /dev/sdb and the drive will probably be /dev/sdb1).
/proc/bus/usb/devices shows you information about the connected USB device.
Most USB devices are formatted FAT32 which has a file size limit of 4GB. Because I'm using mine for Netvault backups and the virtual library media is created at sizes much larger than that, there are 2 choices:
ntfs-3G (which Etch doesn't support) and ext3 (which etch does).
Format to ext3 using
mke2fs -T ext3 /dev/sdb1
Then create an /etc/fstab entry
and mount
Test the (unmounted) disk for bad blocks and write garbage all over each block using
badblocks -c 10240 -s -w -t random -v /dev/sdb
(nb. it's better to use dd if=/dev/urandom of=/dev/sdb but takes much much longer...)
In order to encrypt the whole disk I used this tutorial [1]
apt-get install cryptsetup hashalot
cfdisk /dev/sdb (if you still need to partition the disk, unlikely though)
cryptsetup --verbose --verify-passphrase luksFormat /dev/sdb1
Open the encrypted device and assign it to a virtual /dev/mapper/YOURNAME device:
cryptsetup luksOpen /dev/sdb1 YOURNAME
mkfs.ext3 -m 1 -O dir_index,filetype,sparse_super /dev/mapper/YOURNAME
To mount
mount /dev/mapper/YOURNAME /mnt/
Now it's transparently encrypted
To unmount
umount /mnt/YOURNAME
cryptsetup luksClose /dev/mapper/YOURNAME