VERITAS Volume Manager 3.5 Migration Guide (September 2004)

Chapter 1

VxVM and LVM

Introducing the VERITAS Volume Manager

The VERITAS Volume Manager is an alternative Volume Management product for HP-UX that includes

mirroring features. It offers many capabilities that are not available with the LVM and MirrorDisk/UX

products today.

• The VERITAS Volume Manager can coexist with LVM. Users can decide which volumes they want

managed by each volume manager. For users who want to migrate LVM volume groups to VxVM disk

groups, a conversion utility is included. This utility, vxvmconvert, is described in detail in Chapter 2,

“Converting LVM to VxVM,” on page 9.

• With HP-UX 11i v2, the VERITAS Volume Manager is available for installation with the HP-UX 11i

Application Software. Basic volume management capabilities are available for no extra charge. Advanced

capabilities, such as mirroring, RAID-5, and DMP for active-active systems are available in a separately

licensed product, B9116AA.

• With HP-UX 11i v2, the VERITAS Volume Manager is the default volume manager and can be used

instead of LVM to manage the root disk. Basic volume management capabilities are included in the

operating system. Advanced capabilities, such as mirroring, RAID-5, and DMP for active-active systems

are available in a separately licensed product, B9116AA.

• The VERITAS Volume Manager is integrated with HP MC/ServiceGuard and ServiceGuard OPS Edition

for High Availability, but requires a speciﬁc version of the ServiceGuard products. Refer to the VERITAS

Volume Manager 3.5 for HP-UX Release Notes for details about the required version number, as well as

the availability of speciﬁc features in your release.

Notable Features of VxVM

The VERITAS Volume Manager provides many features, some of which are not available with LVM or

MirrorDisk/UX. Notable VxVM features are described in the list below. See the VERITAS Volume Manager

3.5 for HP-UX Release Notes for a more detailed list of features available in each VERITAS Volume Manager

product. See the other VERITAS Volume Manager documents (listed under “Related Documents” on page iii

in the “Preface” on page iii) for more details about using these features.

VERITAS Volume Manager includes the following features:

• Concatenation, the combining of discontiguous disk regions into virtual devices.

• Spanning, concatenation across different physical media.

• Striping, distribution of storage mappings for a virtual device so that multi-threaded accesses tend to

cause even use of all physical media.

• The VERITAS Volume Manager Storage Administrator, vmsa, a JAVA-based GUI for VxVM. The Storage

Administrator runs either as an application or from a web browser.

• Dynamic Multipathing (DMP) for active-passive devices, such as FC60. DMP provides higher availability

to data on disks with multiple host-to-device pathways by providing a disk/device path failover

mechanism. In the event of a loss of one connection to a disk, the system continues to access the data over

the other available connections to the disk.

• Free Space Management, providing simple goal-based allocation of storage.

• Task Monitor, which tracks the progress of system recovery by monitoring task creation, maintenance,

and completion. The Task Monitor allows you to pause, resume, and stop as desired to adjust the impact

on system performance.