topic Re: difference between LVM and Veritas volume manager in Operating System - HP-UX

difference between LVM and Veritas volume manager

Sprint Unix Team — Fri, 22 Mar 2002 13:34:13 GMT

Whats the difference between LVM and the Veritas volume manager???

Re: difference between LVM and Veritas volume manager

Bill McNAMARA_1 — Fri, 22 Mar 2002 13:38:31 GMT

VxVM can be multi OS.
LVM is HP-UX only.
VxVm devices can be seen and mounted by other oses (file system dependant)
Good for SANs.

LVM is free, apart from mirrordisk, and VxVM interesting stuff is not.

VxVm is GUI based.
VxVM has LOTs of Command Lines. (In rescue mode you must know them.. tough)
LVM must manage boot disk.

See veritas.com for more.
or docs.hp.com

Later,
Bill

Re: difference between LVM and Veritas volume manager

Rita C Workman — Fri, 22 Mar 2002 13:46:00 GMT

Another point difference is that under LVM you have a constraint limit of 65535 physical extents on a disk - VxVM (from my understanding) is supposed to remove that constraint.

If you have support for your systems you might want to contact your HP Account Rep. There is an on-line class being offered for VxVM and you may (under your contract) be able to check it out.
The on-line classes are handy if your having trouble getting away from the office...

Just a thought,
Rita

Re: difference between LVM and Veritas volume manager

Trond Haugen — Fri, 22 Mar 2002 13:55:50 GMT

In consept they do the same. But in differnt ways. Apart from what have already been said.
If you know LVM learning the differenses in VxVM shouldn't bee too hard.

Regards,
Trond

Re: difference between LVM and Veritas volume manager

George A Bodnar — Fri, 22 Mar 2002 14:46:52 GMT

Some other things to keep in mind:

* VxVM is not fully supported by all HP tools yet (Ignite has limitations as does MC ServiceGuard and other tools)
* As mentioned above you can not use this for rootvg so you would have both VxVM and LVM if you went the VxVM route.
* VxVM is the same tool used by Sun and Digital and can be purchased for other Unix flavors as well.
* VxVM does have less limitations regarding size limits (no MAX PE type problems), etc. and is a good bit more flexible.
* Trying to do DR using VxVM is VERY ugly (at least it was when I last used this tool) compared to LVM. In fact we used to use DiskSuite on Sun for root disks to avoid this ugliness...

My opinion. Unless you already know VxVM from other experience stick with LVM since this is basically a version 1 type product with HP support. In fairness VxVM has been available for HP for quite some time, but not under the HP support umbrella.

Re: difference between LVM and Veritas volume manager

George A Bodnar — Fri, 22 Mar 2002 14:48:58 GMT

One thing I forgot above that I did like about VxVM. You have an extra layer (disk => plex => volume) instead of (PV => LV) which allows you to better control/create software striped disks. Also you can do Raid-5 using this software (but this is a pain to manage) which you can not do with LVM.