MC/Service guard SAP extension

[NBB]

Hello,

I have 2 nodes cluster (rx4640 servers) running M/C service guard SAP extension.
I need to change the following:
1-The shared storage (from EVA5000 to another EVA5000)
2-The network ip addresses.

So, can some one advise the best way to do so and if I need to reconfigure SAP configuration files.

Thank you

[D Block 2]

you might treat this 2-node cluster like an upgrade of, say, if you were to install a newer version of mc/sg, i.e., a Rolling Upgrade. You will have to break the cluster anyway to install the new shared array, right?

sounds like you might attempt the ip changes first.. what does you /etc/cmcluster/cluster.conf file look like ?

[Mel Burslan · Accepted solution]

to move the storage from one EVA to another, all you have to do is to modify the .cntl file, i.e., /etc/cmcluster//dbci and modify the lines containing references to the disk information, i.e., VG[n] lines and LV[n] lines. Unless of course, you are keeping them the same, in which case you do not need to do anything. My reference was, in case you will have both of the EVAs up and accesible by these systems for a transitional period of time, in which case, the VG names can not be presented as the same names.

network ip addresses are also easy. In your /etc/cmcluster//dbci file, only things you need to change is the lines with IP[n] and SUBNET[n]. If you are staying in the same subnet, it does not need to change of course.

also in the /etc/cmcluster//sap.config file, find the lines contaning string "RELOC",i.e. NFSRELOC, DBRELOC and CIRELOC and change your relocatable IP address in these lines to reflect your new configuration. If you are not using NFS package, that may be commented out, in which case you do not need to bother with it.

Make sure you propagate the changed files from this node to the other cluster member.

On the cluster configuration file, i.e.,/etc/cmcluster/cmclconfig.ascii (most probably), if you are using lock disk for quorum determination and if it is located on the EVAs, you may need to change the VG information related to the lock disk. Also, if your nodes' individual IP addresses are changing, you will need to modify those in this file as well. Then you will run the cmapplyconf command to compile and distribute the cluster binary.

One very precious advice : Make sure you make backup copies of every file just before you modify it and give them version numbers. In case the crap hits the fan, they will be your best friends. It is also advised to do all you are going to do in a "script" session, so that you can refer what you have done, if something turns out to be broken. Latter part is my advice but first part should be default in any cluster modification.

Hope this helps and good luck

[Volker Borowski]

Hi,

normally you should use servernames everywhere inside SAP and in this case you have only a few things to check:

1) DNS should have correct PTR mappings. SAP gives some strange messages if something is wrong with the name-resolution.
2) RFC-Destinations inside SAP may be stored as IP-Address allthough entered as Hostname (default unfortunately). You need to check transaction SM59 in the changed system and in the systems that might comunicate with yours (i.e. DEV and QAS for transport reasons). It might be neccessary to re-configure TMS, because the RFC-destinations are generated an might not be modifiable (reconfigureing TMS requires an admin user in client 000 of all affected SAP-Systems).
3) GUI-Frontends should use DNS. In case they don't, you need to adjust comunication parameters at the frontend.
4) If database is Oracle, check SQL-NET config. /oracle/SID/920_64/network/admin -> *.ora files
5) In case other systems that use names in SM59 stay up during your change, it might be neccessary to reset the hostname-buffer inside SAP (should be in SMGW) of these systems.
6) as far as I remember, IP-change should not affect your SAP-licensekey. Check your Hardware key with "saplicense -get" before and after your change on both nodes. If it is the same, you should not need a new key.
7) SAP profiles are in /sapmnt/SID/profile, but they should not contain IP-Adresses.
8) If you use a central Backup tool, not only check the filesystem backup, but the DB-integration as well.

Good luck
Volker
Volker