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need for online VG extend possibilities

Super Advisor

need for online VG extend possibilities

Hi,

 

Pleaes find the present setup i have in our environment, we have sd2 super dome hardware and installed os is hp-ux 11.31.

we have to presnet new LUN in the server . production application is running

 

 

Question

1.in hp-ux 11.31 it is possible to extend the VG online without stoping the production application. because we know very well LV possoble to extend online. but i want to know. it is possible to extend the VG online

 

 

 

 

4 REPLIES
Honored Contributor Honored Contributor

Re: need for online VG extend possibilities

Once you have created the new LUN from your storage system, and verified that it is visible to the OS via 'ioscan', you can add it to the VG.

 

To do this you use the vgextend command and this can be done without any downtime.

 

If your new disk is /dev/disk/disk23 and your volume group is VG03 then you can do:

 

# pvcreate /dev/rdisk/disk23

 

# vgextend /dev/vg03 /dev/disk/disk23

 

Now you  have a new disk in your VG.

Highlighted
Honored Contributor Honored Contributor

Re: need for online VG extend possibilities

You can extend the VG without stopping production.  But first verify the VG limitations with vgdisplay. It will tell you what the maximum number of LUNs allowed (Max PV), and the largest LUN that can be added using the formula: PE_Size * Max_PE_per_PV.

Super Advisor

Re: need for online VG extend possibilities

thanks for your reply

 

that production server is Data base server ,in this server 3 node cluster service running, so shall do the VGextend online .

 

please confirm vgextend affect any cluster service or we need to down the cluster before the activity or we need to move the cluster in debug mode.  pleae confirm

Occasional Advisor

Re: need for online VG extend possibilities

You need to identify/verify first that the VG is under what package and what nodes are involved on that package.

 

If lets say, that VG is on the identified package and that package is currenly running on the Primary node only, then you can extend the VG online.

 

1. Prepare a new disk or LUN; do a pvcreate on that disk/LUN

 

2. Perform vgextend

 

Afterwhich, you will need to get the latest mapfile of the updated VG.

 

3. vgexport -p -v -s -m /etc/lvmconf/vgNAME.map   /dev/vgNAME

 

4. copy over the mapfile from Node1 to Node2 or Node3 - whichever is the concerned Secondary node.

 

then do vgexport and vgimport on the Secondary node.

 

5. vgexport vgNAME

 

6. vgimport -v -s -m /etc/lvmconf/vgNAME.map   /dev/vgNAME

 

That's it.

 

 

Cheers!