topic Re: vxvm default parameters for volume creation in Operating System - HP-UX

vxvm default parameters for volume creation

Vanja — Fri, 22 Sep 2006 14:50:09 GMT

Hi,

Was trying to find out the default values for vxvm when creating volumes. I'm using vxvm 4.1. Specifically what are the default max values for # of plexes/subdisks/disks per volume? I know that the max number of subdisks per plex is around 4000.

Also are these max parameters configurable?

I know LVM in HPUX has some defaults that can't be changed so want to make sure that I get vxvm straight.

Thanks,
Vanja

Re: vxvm default parameters for volume creation

Geoff Wild — Fri, 22 Sep 2006 17:20:21 GMT

Defaults values used by vxassist are in:

/etc/default/vxassist

See the following for more info:
http://docs.hp.com/en/5187-1369/ch07s04.html

Rgds...Geoff

Re: vxvm default parameters for volume creation

Vanja — Sun, 24 Sep 2006 04:54:39 GMT

Hi,

Thanks for the info. I checked the vxassist defaults previously, but couldn't find information with regards to what I'm looking for. Looked through a bunch of the man pages, but couldn't find the info.

Question:

What are the default max values for # of plexes/subdisks/disks per volume in vxvm 4.1? I know that the max number of subdisks per plex is around 4000.

Thanks for the assistance. Points will be rewarded promptly.

Vanja

Re: vxvm default parameters for volume creation

Vanja — Mon, 25 Sep 2006 10:54:34 GMT

Anyone? Guess I'll need to open up a case.

Thanks,
Vanja

Re: vxvm default parameters for volume creation

IT_2007 — Mon, 25 Sep 2006 10:57:13 GMT

Please post results if you find any details from the Vendor.

Re: vxvm default parameters for volume creation

Jonathan Fife — Wed, 27 Sep 2006 07:40:28 GMT

Just for the sharing of information, here is what my contact at Symantec said:

There is a limit to the number of subdisks that can be created in a disk group, but it's not a fixed number. By that I mean that much like LVM has its PVRA where mapping info goes, VxVM has its private region where its data objects go. A practical number for a limit for the number of subdisks would be in the low thousands. A properly created volume should not have very many subdisks, if it were created with forethought.

The maximum number of plexes per volume is 32.

Re: vxvm default parameters for volume creation

Vanja — Wed, 27 Sep 2006 23:20:54 GMT

Thanks for the info!

For further clarification here's the info I got from HP.

Max subdisks per plex: 4096
Max plexes per volume: 32

Vanja