MCSG: Removing A Logical Volume From MCSG Configuration

[LG Porter]

I have two K580 class servers running HPUX 10.20, in a MCSG (10.10) configuration. What is the best method for removing a logical volume from ServiceGuard configuration? Can this be done while the cluster is online? Thanks

[James R. Ferguson · Accepted solution]

Hi:

To remove a logical volume, unmount the filesystem associated with the logical volume and 'lvremove' the logical volume and edit your package control script (if it contained reference to the logical volume). If the package is using this logical volume, you will need to take the package down, otherwise it can be left running.

Since knowledge of a logical volume is obtained at the time its volume group is activeated, and you are not (or did not indicate) that you are changing the volume group, then this should be all that's necessary.

Regards!

...JRF...

[PIYUSH D. PATEL]

Hi,

It can be done when the cluster is online. You will have to see that no users are using that logical volume and it is not been used by any package.

1.Unmount the logical volume
2. Use lvremove to remove the lvol
3. Then remove it from the package control script.

Piyush

[Sridhar Bhaskarla]

Hi,

As indicated by others, you don't need to bring down ServiceGuard to remove a logical volume.

However, you need to remove the pointers wherever they exist. On primary node, follow the default procedure for removing a logical volume. Modify your control file to remove the references and distribute it to the secondary node.

Export the volume group with "preview" option and generate a map file. Copy it to the secondary node.

Export the volume group completely. Use the standard mkdir and mknod commands to create the volume group directory/group device files. Then import the volume group using the map file that you copied from the primary node.

This will make the things clean.

-Sri

[Stephen Doud]

In response to this question, I created document UMCSGKBRC00010152
Title: Removing a logical volume from a ServiceGuard package

The forums reply box does not preserve formating so I am hesitant to copy the document here.

If you would like me to email copy to you, please send an email to hpcu@atl.hp.com
Use the subject: To Stephen - Forum issue

Or, check the ITRC knowledge base in a day or so when it loads.

-s.

[MANOJ SRIVASTAVA]

Hi LG


Well there is simply way to do it .
1. Take backups for the lvol if required.
2. unmount the logical volume .
3. lvremove it from the volume group.
4. edit /etc/cmcluster/cluster name / control script to remove the entry form the contriol file

You are good to go.


Manoj Srivastava

[James R. Ferguson]

Hi Stephen:

Thanks for an excellent, very well-written document!

*Question*: Why is your document cataloged with an id of UMCSG* when it is well-known (?) that a search for UXSG* will yield MC/ServiceGuard documentation lists?

Regards!

...JRF...

[James R. Ferguson]

Hi (again) Stephen:

Well, anyway, it appears that a larger set of MC/ServiceGuard documents can be gleaned from the TKB with the search string "u*sg*". However, my question (above) remains. Thanks!

Regards!

...JRF...