topic Re: VxVM Vs LVM in Operating System - HP-UX

VxVM Vs LVM

George Petrides_1 — Tue, 22 Oct 2002 12:57:28 GMT

Just out of curiosity, what do you guys think about VxVM? I have been dealing with LVM since 94 and never touched the Veritas' product. I read the documentation and it seems very similar but anybody can give a comparison how VxVM does the job compared to LVM.
TIA,
George

Re: VxVM Vs LVM

Jean-Louis Phelix — Tue, 22 Oct 2002 13:05:54 GMT

Hi Georges,

What I could say is that once you are familiar with LVM, VxVM seems MUCH more complicated ...

In this doc you have a chapter on LVM/VxVM conceptual comparison.

Regards,

Jean-Louis.

VxVM and LVM

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This chapter provides an overview of the VERITAS Volume Manager (also referred to as VxVM) and its features. A brief description of the benefits of migrating from the HP-UX Logical Volume Manager (LVM) to VxVM, and the coexistence of VxVM disks with LVM disks is also given.
The following topics are discussed in this chapter:

Introducing the VERITAS Volume Manager
VxVM and LVMConceptual Comparison
Coexistence of VxVM and LVM Disks

http://www.docs.hp.com/hpux/onlinedocs/B7961-90017/B7961-90017.htm

Re: VxVM Vs LVM

Helen French — Tue, 22 Oct 2002 13:27:48 GMT

This document may be helpful for a comparison (TKB#VxVM003):
http://www1.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062922881

Re: VxVM Vs LVM

Ashwani Kashyap — Tue, 22 Oct 2002 13:31:22 GMT

I tried and VxVM is much more complicated than LVM . Some of the concepts was very difficult to understand unlike LVM .

I would take LVM any day .
HP is not planning to get rid of LVM ? Are they ?

Re: VxVM Vs LVM

S.K. Chan — Tue, 22 Oct 2002 13:31:48 GMT

Similar in some sense but NOT quite. Personally we have not moved to VxVM yet, maybe because there's no urgency to migrate yet. There are some features in VxVM that are not available from LVM that should be the points for consideration when you decide to move. This is from some text that I saved up early this year. I particularly liked the DMP feature in VxVM that allows you to do load balancing (this feature has to be purchased separately) that LVM does not provide.
- A JAVA-based administrative GUI. The Storage Administrator can run either as a system application or from a web browser.
- Provides simple, goal-based storage allocation.
- Tracks progress of system recovery operations 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.
- Dynamic Multipathing (DMP) for Active/Active Devices. Provides high availability to data on disks with multiple host-to-device pathways by providing a disk/device path failover mechanism and by providing load balancing. (LVM supports path failover but does not support I/O balancing.)
- Multiple mirroring allows up to 32 mirror copies of a volume.
- Mirrored stripes (RAID-1 + RAID-0) and striped mirrors (RAID-0 + RAID-1).VxVM both support the combination of mirroring and striping.
- The hot relocation process, vxrelocd(1M), automatically moves failed subdisks to available disk space within the same disk group. This allows a system to react automatically to I/O failures on redundant (mirrored or RAID-5) VxVM objects, restoring redundancy and access to those objects without administrative intervention.
- Online Data Migration allows storage regions on physical media to be dynamically moved to other physical devices.
- Online Relayout allows you to change logical data configuration while online; for example, you can change a RAID-5 layout to a mirrored layout if you have enough disk space. The volume data remains available during the relayout operation.

Re: VxVM Vs LVM

Pete Randall — Tue, 22 Oct 2002 14:04:13 GMT

George,

It's important to note that there are two separate VxVM products - the base product and the "advanced" product. In my opinion, most of the goodies are in the advanced product: DMP, Multiple mirroring, Mirrored stripes, Hot-relocation, RAID-5, Online Data Migration, Online Relayout or Dynamic Restriping, etc.

With what's offered in the "no-additional charge" base product, I just don't see that it's worth the effort to convert.

Pete