How to enable EVFS raw access mode for encrypted backup

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Abstract[edit]

This article explains how to set an EVFS volume to raw mode access.

Procedure[edit]

There is no way to set the EVFS volume to raw mode without unmounting the EVFS Filesystem, as it always complains about a Device been busy when you disable the encryption:

For example:

# evfsvol disable -k test /dev/evfs/vg00/test
Enter user passphrase:
evfsvol: disable error: cannot disable EVFS volume "/dev/evfs/vg00/test", evol is busy

To unmount the file system is required in order to set the EVFS to raw mode.

For example:

# bdf
Filesystem          kbytes    used   avail %used Mounted on
/dev/vg00/lvol3    2097152  757912 1328848   36% /
/dev/vg00/lvol1     524288  241976  280288   46% /stand
/dev/vg00/lvol16   17776640 9368423 7886766   54% /var
/dev/vg03/lvol1    53329920 49321997 3757490   93% /var/opt/ignite
/dev/vg00/lvol7    8388608 3171576 5176344   38% /usr
/dev/vg00/lvol6    1605632  634216  970016   40% /tmp
/dev/vg00/lvol5    8388608 7463224  918248   89% /opt
/dev/vg00/lvol4    1228800  136208 1084136   11% /home
/dev/evfs/vg00/test
                    105976    1754   97716    2% /test
# umount /test
# evfsvol disable -k test /dev/evfs/vg00/test
Enter user passphrase:
Encrypted volume "/dev/evfs/vg00/test" has been successfully disabled
# evfsvol raw /dev/evfs/vg00/test
Are you sure you want to enable raw access to "/dev/evfs/vg00/test"?
Raw access returns encrypted data to the user.
Answer [yes/no]:yes
Successfully enabled raw access to EVFS volume "/dev/evfs/vg00/test"

There is no way to mount the filesystem back if the EVFS is in raw mode:

# mount /dev/evfs/vg00/test /test
/dev/evfs/vg00/test: unrecognized file system

Writing data to or reading data from an EVFS volume when it is opened for raw access can cause data corruption. Hewlett-Packard recommends to use this operation only when creating encrypted backup media or restoring encrypted backup media, as described at Backing Up EVFS Volumes.

Reference[edit]

  • Encrypted Volume and File System v1.1 Administrator's Guide: HP-UX 11i v2 Update 2 and 11i v3 - Chapter 7 Backing Up and Restoring Data on EVFS Volumes - Backing Up EVFS Volumes

Authors[edit]