How to add a 3rd node to an existing 2 node cluster?

[Donny Jekels]

Is it possible to to this online, I am new to MC/SG?

Thanx
Donny

[Sridhar Bhaskarla]

Hi Donny,


Yes. You can add a new node to the cluster if the cluster is up and running. Look at the following document for more details.

http://docs.hp.com/hpux/onlinedocs/B3936-90079/B3936-90079.html

"Reconfiguring a cluster" section.

-Sri

[G. Vrijhoeven]

Hi Donny,

Yes this is possible. Online, but i am afraid you need to check the documentation first:
http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B3936-90079/B3936-90079_top.html&con=/hpux/onlinedocs/B3936-90079/00/00/50-con.html&toc=/hpux/onlinedocs/B3936-90079/00/00/50-toc.html&searchterms=a%7cnode%7cadd&queryid=20040902-085813

HTH,

Gideon

[Sridhar Bhaskarla]

Hi (Again),

regarding how

1. Take a backup of your cluster configuration file. Edit the configuration file and add the server details in there (name, network interfaces, heartbeats etc.,). You don't need a lock disk for a three node cluster.

2. Make sure you import the VGs specified in the cluster ascii file on the third node.

3. Apply the configuration.

cmapplyconf -C your_cluster_ascii

Fix the errors any generated during the above operation. 'cmcheckconf' can also give that information without applying the configuration but I don't use it often as cmapplyconf will fail anyway if there are any errors.

-Sri

[Sundar_7]

Donny,

Rather than creating the cluster configuration manually, I would rather have cmquerycl create the configuration file for me

1) cd /etc/cmcluster
cmquerycl -v -C cluster.conf -n node1 -n node2 -n node3

2) Edit the cluster.conf and modify the parameters as required. In most of the cases this is not required

3) Import the volume groups to the new node.

4) Copy the package directories to the new node

5) Check the configuration file with cmcheckconf and apply the configuration file with cmapplyconf

6) In the new node, make sure you edit /etc/lvmrc file and set AUTO_VG_ACTIVATE to 0 and list vg00 in the custom_vg_activation() section

7) Create the mount points for the packages and set AUTOSTART_CMCLD=1 in /etc/rc.config.d/cmcluster file if you would like the node to join the cluster automatically at bootup.

-- Sundar.

[Rita C Workman · Accepted solution]

Just sent an email the other day to someone on doing this...figured I'd paste it in here too.

Adding a node to a running cluster:

cmgetconf -v -c cluster_name temp.ascii to get the current cluster config
cmquerycl -n node1 -n node2 -C newcmclconf.ascii to gather information on old node plus new node
Now combine the ascii files...temp.ascii & newcmclconf.ascii....into one file using vi
cmcheckconf -v -C to check your new ascii file
cmapplyconf -v -C apply your new ascii file once your check is clean !

Then remember to go back and move/rename your old files, so you don't get confused later as to which one is the active file.

Now just start up the new node
cmrunnode node2


HTH,
Rita

[Steven E. Protter]

Please give Rita 10 points. That will put her within 1 of Pharoh.

I checked my text book. Its a good answer.

:-)

SEP

[Geoff Wild]

Rita's will work!

All High Availability docs are here:

http://docs.hp.com/hpux/ha/

New to MC/SG - read those docs, take a course from HP:

http://www.hp.com/education/courses/h6487s.html

http://www.hp.com/education/courses/h4310x.html

Rgds...Geoff

[Donny Jekels]

Rita,

Congrats, your answer was the best of the lot and got me going in no time at all.

All else, its nice to read those long drawn out docs, and having the links in hand, but sometimes teh links is more of a pain than anything else.

quick steps to get going is in most cases to best solution - for me anyway.

Donny
Rita. I was going to give you 10 points anyway wihtout SEP's recommendation, I got way to busy finnishing the project, with your guidance. If you reply again, I will give you another 10. Congrats on your progress in the forums, good luck.