Veritas Storage Foundation 5.1 SP1 Advanced Features Administrator"s Guide (5900-1503, April 2011)

More than one Volume Group or pattern may be entered at the
prompt. Here are some LVM Volume Group selection examples:
all: Rollback all converted LVM Volume Groups
listvg: list all LVM Volume Groups eligible for rollback
list: list all disk devices
vg_name: a single LVM Volume Group, named vg_name
<pattern>: for example vg08 vg09 vg05
Select Volume Group(s) to rollback :
[<pattern-list>,all,list,listvg,q,?]
vg08
Roll back this Volume Group? [y,n,q,?] (default: y)
Rolling back LVM configuration records for Volume Group vg08
Selected Volume Groups have been restored.
Hit RETURN to continue.
Rollback other LVM Volume Groups? [y,n,q,?] (default: n)
General information regarding conversion speed
The speed of the process of converting an existing LVM volume group to a similar
VxVM disk group is largely dependent upon the size of the volume group being
converted, as well as on the complexity of the volumes within that volume group.
Note: The vxvmconvert operation displays an estimated time before the actual
conversion is committed.
Factors affecting conversion speed include:
■ Size of volume groups. The larger the volume groups, the larger the LVM
metadata on each disk. A copy must be made of the LVM metadata for each
physical disk. Some areas are greater than 2MB; therefore, a 50-disk volume
group requires 50 2MB reads and writes (i.e., 100 large I/Os) to complete.
■ Individual size of a logical volume in a volume group, and the complexity of
the logical volume layout. For example, for a system with 50 9GB drives, a
simple 50GB logical volume of the first 5 1/2 disks can be created. But a 50GB
striped logical volume that takes the first 1GB of all 50 disks can also be created.
The first and simple logical volume takes less time to convert than the striped
volume. However, for the striped volume, 50 disks need to be checked. Also,
the complexity of reproducing the VxVM commands to set up the striped
volumes requires more VxVM commands to be generated to represent more
smaller sub-disks representing the same amount of space.
431Offline data migration
Converting LVM to VxVM