VERITAS Volume Manager 3.5 Migration Guide (August 2002)

Chapter 3, Command Differences

Final 24 July 2002 Existing Features in LVM not supported in VxVM

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.

Create a snapshot copy of a volume. vxassist snapshot vol_name

temp_vol_name

Recover a volume. vxrecover -g disk_group volume

medianame

vxmend fix clean plex_name

Repair a mirror vxplex att plex_name

Disable a mirror vxplex det plex_name

Remove a log from a volume. vxassist remove log vol_name

Move a subdisk. vxsd mv old_subdisk new_subdisk

Table 4. Additional VxVM Tasks with no LVM equivalents

Task Description Example

Table 5. 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

volumegroup (VG) and physicalvolume 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 thepfto 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.