Encrypted Volume and File System v2.2 Administrator Guide (777846-001, April 2014)

5. Use the strings utility and try to find the text. The strings utility will not find the text
because it receives data from the EVS volume in encrypted form.
6. Return the EVS volume to a working state. Close raw access using the following command:
evfsvol close evfs_volume_path
Enable the volume using the following command:
evfsvol enable –k keyname evfs_volume_path
Remount the file system using the mount command.
Example
In the following example, the administrator writes the string TOP SECRET TOP SECRET to the
EVS volume. When the administrator uses the strings command to search the EVS volume for
this string, the search is successful. When the administrator searches the underlying LVM volume
for the same string, the search is unsuccessful.
# echo "TOP SECRET TOP SECRET" > /opt/encrypted_data/my_evfs_test
# strings /dev/evfs/vg01/lvol5 | grep "TOP SECRET"
(The strings command finds the string "TOP SECRET" on the EVS volume.)
TOP SECRET TOP SECRET
(Disable EVFS so we open raw access to the file)
# fuser -cku /opt/encrypted_data
# umount /opt/encrypted_data
# evfsvol disable /dev/evfs/vg01/lvol5
Enter user passphrase: (enter the passphrase)
# evfsvol raw /dev/evfs/vg01/lvol5 (EVFS will print a warning and ask
if you want to continue)
# strings /dev/vg01/lvol5 | grep "TOP SECRET"
(The strings command does not find the string "TOP SECRET")
# evfsvol close /dev/evfs/vg01/lvol5
# evfsvol enable /dev/evfs/vg01/lvol5
Enter user passphrase: (enter the passphrase)
# mount -F vxfs /dev/evfs/vg01/lvol5 /opt/encrypted_data
Step 4: (Optional) Migrating existing data to an EVS volume
Use the following procedure to migrate an existing directory of data to the EVS volume:
a. For data consistency, stop all applications accessing the data. You can use the fuser -cu
command to determine the processes accessing files, and the fuser -cku command to
terminate the processes. For more information, see fuser(1M).
If the data is used by system processes, you might need to terminate the processes by changing
the system runlevel to single-user level with the shutdown utility. For more information, see
shutdown(1M).
b. (Optional) Create a backup of the existing data.
c. Use the cp command or other utility to copy the data from the existing files to an EVS volume.
d. (Optional) Remove the old files or directories. If you migrated all the data from a file system,
you can unmount the old file system. For more information, see umount(1M).
e. (Optional) If you unmounted a file system in the previous step, remove the entry for the file
system from the /etc/fstab file.
f. (Optional) Use the ln command to create a symbolic link from the old directory to the
appropriate directory on the encrypted volume. For more information, see ln(4).
g. Restart applications that use the data as needed.
Example
In the following example, the /opt/encrypted_data directory is located on an EVS volume
has already been created and enabled.
54 Configuring an EVS volume