Administrator's Guide

6. EVFS encryption and decryption must be enabled on the target volume also. Use the evfsadm
stat -a or evfsvol display evfs_volume_path command to verify that EVFS is
enabled on the target volume. In this example, /dev/evfs/vg01/lvol6 is a spare EVFS
volume that will be used as the backup target device:
# evfsvol display /dev/evfs/vg01/lvol6
7. Create encrypted backup media by using dd to copy the entire volume to a second EVFS
volume that is also enabled.
For example:
# dd bs=64k if=/dev/evfs/vg01/lvol5backup of=/dev/evfs/vg01/lvol6
8. Disable the EVFS backup volume to begin the procedure to return the backup volume to its
original state. For example:
# evfsvol disable -k mykey /dev/evfs/vg01/lvol5backup
The evfsvol utility prompts you for the passphrase if a stored passphrase does not exist.
9. Unmap EVFS volume using the evfsadm unmap command. For example:
# evfsadm unmap /dev/evfs/vg01/lvol5backup
10. Merge the backup volume back with the original LVM volume using the lvmerge command.
For example:
# lvmerge /dev/vg01/lvol5backup /dev/vg01/lvol5
Example
In the following example, the administrator splits the /dev/vg01/lvol5 mirror volume and
creates the /dev/vg01/lvol5backup volume. The target is the EVFS
volume/dev/evfs/vg01/lvol6. The dd command receives cleartext from the source EVFS
volume and the target EVFS volume encrypts the data.
# lvsplit –s backup /dev/vg01/lvol5 (LVM creates the /dev/vg01/lvol5backup volume.)
# evfsvol map /dev/vg01/lvol5backup
# evfsvol check -r /dev/evfs/vg01/lvol5backup
# evfsvol enable -k mykey /dev/evfs/vg01/lvol5backup (evfsvol prompts for
a passphrase if there is no stored passphrase.)
# evfsvol display /dev/evfs/vg01/lvol6 (Verify that the target EVFS volume is enabled)
# dd bs=64k if=/dev/evfs/vg01/lvol5backup of=/dev/evfs/vg01/lvol6
# evfsvol disable -k mykey /dev/evfs/vg01/lvol5backup (evfsvol prompts for
a passphrase if there is no stored passphrase)
# evfsadm unmap /dev/evfs/vg01/lvol5backup
# lvmerge /dev/vg01/lvol5backup /dev/vg01/lvol5
108 Backing Up and Restoring Data on EVFS Volumes