VERITAS Volume Manager 4.1 Migration Guide

Command Differences
Existing Features in LVM not supported in VxVM
Chapter 3 69
Existing Features in LVM not supported in VxVM
Some of the existing features in LVM are not supported in the current release of VxVM. Given
below is a table with the unsupported LVM features, and possible workarounds in VxVM.
Table 3-4 LVM features and VxVM equivalents
LVM Feature VxVM Equivalent
Physical volume groups VxVM has no equivalent feature. The disk
group feature of VxVM combines the logical
volume group (VG) and physical volume group
(PVG) of LVM.
Powerfail timeout feature:
Automatically re-enable a disk or a
path to a disk, after temporary error
condition (resulting in EPOWERF
error on I/Os) disappears on that disk
or path.
Powerfail timeout feature: After the EPOWERF
error condition disappears, the reconfiguration
command must be run manually to re-enable
the paths and the disks which were disabled
due to EPOWERF error. See the pfto feature in
the vxdctl command manual pages for more
information.
Logical Volume Timeout (LVTO). If
LVTO on a logical volume is set to
zero, which is the default, an I/O is
retried forever.
VxVM does not support the LVTO feature.
However, VxVM supports the powerfail timeout
feature to handle transient error conditions.
VxVM tries an I/O only on active paths to a
disk; hence, it never retries indefinitely. See the
powerfail timeout feature and also refer to the
pfto feature in the vxpfto manual pages for
more details.
Bad media block relocation. VxVM relocates whole subdisks. Smaller
granularity relocation is not supported. The bad
block reallocation feature does not exist in
VxVM because the vectoring of bad blocks is
now done by most hardware.