non-exclusive volume group activation

[Cristi BODNARIUC]

Hi,

Is it possible to use non-exclusive activation of a vg created with LVM in a 2-node cluster?

For example I'd like to create 2 packages, 2 logical volumes on a volume group, one for the first package and the other for the second package, but I'd like to activate packages on different nodes.

Thanks,
Cristi

[Massimo Bianchi]

Yes, but at your own risk.

I would go with two VG, what you plan to do is completely unsupported.....

Massimo

[Ian Dennison_1]

If there is a need to share, why not use NFS?

I would not like to try sharing ownership of lvols at the VG level.

Share and Enjoy! Ian

[melvyn burnard]

you cannot have one VG shared between multiple packages.
Each VG can belong to only one package.
you would need at least 2 vg's here, one for each package.

[Romaric Guilloud · Accepted solution]

Cristi,
By default, vg activation within a package control script is done by:
vgchange -a e

Therefore, once you package is started, you would not be ableto activate it on the other hand unless you change the vg activation policy for the package (which is not recommended).
Should yous still decide to do so, you must first issue:
vgchange -c n
before activating it back into shared mode.

Sincerely,

Romaric.

[Michael Steele_2]

Not only can you not do this but you also can't mount your file systems with /etc/fstab. All of your file systems need to configured and mounted via the 'package.cntl' and 'package.conf' files.

vgchange -c y /dev/vg##

And then vg activation occurs via the package at 'cmmodpkg -e package'.

[Tim D Fulford]

Hi

If you have a lack of disks for your VG you have a few options, none that great

1 - Run both processes under one package
2 - run one process unbder package 1 with accosiated VG and run the other WITHOUT any accociated VG.
3 - buy more disks & create a new VG OR if you have a VA/XP or something where you can create a variable sized LUN, create two smaller LUNs, one for each package

2 is not as stupid as it may at first sound. If the only things required to run the process are binaries & configuration files (i.e. things that do not change much) these can be put on your local disks (usually vg00). This type of method works best in a cluster with an application/database type of split. The application usually does not require any disk for it's data as it uses the database!

May luck follow you...

Tim