Veritas Volume Manager 5.0 Migration Guide, HP-UX 11i v3, First Edition, May 2008

68 Command differences

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(1M) manual page 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.