As the name suggests, dm-crypt uses device-mapper to establish a crypto
mapping. In general you'll have a physical block device (actually other
dm targets work too, but I'll ignore this for now) and a crypto mapping
which is exported as a virtual block device. Thus all read/write
operation on the virtual block device get encrypted whilst
writing/reading to the underlying blockdevice.
Example:
Block-Device (/dev/sda) -> Crypto Mapping -> Virtual Blockdevice
(/dev/md....)
Block-Device (/dev/ramN) -> Crypto Mapping -> Virtual Blockdevice
(/dev/md...)
If you really plan to encrypt a ramdisk (why'd one want to do that
anyway?) you'd have to setup a mapping on a ramdisk blockdevice.
Regards
-Sven
Bai Shuwei schrieb:
Thanks Sven, I want to know how the dm-crypt work. And learn how to
configure the crypto disk and use it.
On 6/18/09, Sven Eschenberg <sven@xxxxxxxxxxxxxxxxxxxxx> wrote:
I'd recommend reading the dmsetup man page as well as the cryptsetup man
page. You might want to use cryptsetup for what you are trying to achieve.
Aside from that, what were you trying to achieve there?
Regards
-Sven
Bai Shuwei schrieb:
Hi, all:
I want to use the ram disk as my cryption target disk. This is my
command:
# dd if=/dev/zero of=dmf count=4096 bs=4096
# sudo dmsetup create dmf
2.6.24-16-generic,
Library version: 1.02.20 (2007-06-15)
Driver version: 4.12.0
but it will be blocked here. But I don't kown what wrong with it. Do
you
some idea on it or do you some idea learning dm-crypt?
Thanks all!
Best Regards!
Bai Shuwei
---------------------------------------------------------------------
dm-crypt mailing list - http://www.saout.de/misc/dm-crypt/
To unsubscribe, e-mail: dm-crypt-unsubscribe@xxxxxxxx
For additional commands, e-mail: dm-crypt-help@xxxxxxxx
---------------------------------------------------------------------
dm-crypt mailing list - http://www.saout.de/misc/dm-crypt/
To unsubscribe, e-mail: dm-crypt-unsubscribe@xxxxxxxx
For additional commands, e-mail: dm-crypt-help@xxxxxxxx
