The Crypt Mapping Target - Red Hat ENTERPRISE LINUX 5 - LOGICAL VOLUME MANAGER ADMINISTRATION Manual

0 71014400 multipath 0 0 1 1 round-robin 0 4 1 66:112 1000 \
67:176 1000 68:240 1000 65:48 1000
For further information about multipathing, see the Using Device Mapper Multipath document.
A.1.8. The crypt Mapping Target
The crypt target encrypts the data passing through the specified device. It uses the kernel Crypto
API.
The format for the crypt target is as follows:
start length crypt cipher key IV-offset device offset
start
starting block in virtual device
length
length of this segment
cipher
Cipher consists of cipher[-chainmode]-ivmode[:iv options].
cipher
Ciphers available are listed in /proc/crypto (for example, aes).
chainmode
Always use cbc. Do not use ebc; it does not use an initial vector (IV).
ivmode[:iv options]
IV is an initial vector used to vary the encryption. The IV mode is plain or essiv:hash. An
ivmode of -plain uses the sector number (plus IV offset) as the IV. An ivmode of -essiv
is an enhancement avoiding a watermark weakness
key
Encryption key, supplied in hex
IV-offset
Initial Vector (IV) offset
device
block device, referenced by the device name in the filesystem or by the major and minor numbers
in the format major:minor
offset
starting offset of the mapping on the device
The following is an example of a crypt target.
0 2097152 crypt aes-plain 0123456789abcdef0123456789abcdef 0 /dev/hda 0

The crypt Mapping Target

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