Administrator's Guide

Limitations and Known Problems When Using EVFS with Volume Managers
and File Systems
The following limitations and known problems exist when using EVFS with volume managers
(LVM and VxVM) and file systems. For a complete list of product limitations and known problems,
see “Product Limitations and Precautions” (page 27) and “Known Problems” (page 29).
Creating a New EVFS Volume Overwrites Existing Data
EVFS does not automatically convert existing volume data to encrypted data. To encrypt existing
volume data, see “Step 4: (Optional) Migrating Existing Data to an EVFS Volume” (page 61).
CAUTION: If you configure EVFS on a volume that already contains data without following
“Step 4: (Optional) Migrating Existing Data to an EVFS Volume” (page 61), the existing data is
rendered unusable.
vxresize –F Might Cause Data Loss or Corruption
The vxresize –F command resizes a VxVM volume and the file system mounted on the
volume. The vxresize command has no knowledge of EVFS, so if you configure EVFS on a
VxVM volume and then execute the vxresize –F command, vxresize will not allocate space
for the EVFS data structure (the EMD) on the volume. The vxresize -F command will
complete, but file operations might fail; data might be lost or corrupted.
Workaround
Resize the VxVM volume and file system in separate operations. Use the vxassist command
to increase or decrease the VxVM volume size (or the vxresize command without the –F
option). Use the extendfs or fsadm command to resize the file system. See “Resizing EVFS
Volumes and File Systems” (page 97) for more information.
Renaming VxVM Volumes with EVFS Enabled Makes the Volume Unusable
The vxedit rename command renames a VxVM volume. The vxedit rename command
has no knowledge of EVFS, so if you have a VxVM volume with EVFS enabled and then rename
the volume, the mapping between the VxVM volume becomes unusable. The vxedit rename
command will complete, but EVFS operations will fail.
Workaround
Disable and unmap the EVFS volume before renaming the underlying VxVM volume, as described
in “Disabling Encryption/Decryption Access to EVFS Volumes” (page 81). After you rename the
VxVM volume, use the following procedure to access the EVFS volume again:
1. Map the new VxVM volume name to EVFS using the evfsadm map volume_path
command.
2. Enable the EVFS volume using the evfsvol enable evfs_volume_path command.
NOTE: Do not use the evfsvol create command to create a new encryption metadata
(EMD) area on the volume. The EMD area already exists on the volume.
96 Managing Data on EVFS Volumes