We are planning to upgrade our SEPM server from 11.6 to 12.x. So I am looking for proper procedures.
 

Its same like the previous ones, Do you have replication in place?

Always take back up of your existing infrastructure.

If you have replication in place, then stop the replication , run the upgrade on server1

follow the same procedure on server2

once SEPM is updated, use auto upgrade feature to upgrade your clients.

See the Chetan Articleto upgrade with process

If you are running with Embedded databse then follow the article

SEPM 11.x to SEPM 12.1 Upgrade process graphical overview with Embedded database

https://www-secure.symantec.com/connect/articles/sepm-11x-sepm-121-upgrade-process-graphical-overview-embedded-database

If you are running with SQL databse then follow the article

SEPM 11.x to SEPM 12.1 Upgrade process graphical overview with SQL database

https://www-secure.symantec.com/connect/articles/sepm-11x-sepm-121-upgrade-process-graphical-overview-sql-database

--Edit--

All the upgradation plan in the article

Upgrade or migrate to Symantec Endpoint Protection 12.1.5

See here:

Upgrade or migrate to Symantec Endpoint Protection 12.1.5

Hi,

Thank you for posting in Symantec community.

I would be glad to answer your query.

On January 5th, 2015, Symantec Endpoint Protection version 11.0.x will reach end of support life. Virus definitions and security updates will cease to be published to LiveUpdate and general support for the product will no longer be provided.

The initial end of support life date was originally scheduled for January 5th, 2014. All customers were provided a complimentary extention. No further extentions will be provided.

It's strongly recommended to upgrade to SEP 12.1, RU5 is the latest release.

To know the best practice I would recommend you to go through the following article.

https://www-secure.symantec.com/connect/articles/sep-11x-sep-121-upgrade-process-graphical-overview

Important note: The SEP 12.1 SEPM upgrade installer requires three times the current database size (sem5.db) if upgrading from pre-12.1 SEPM with the embedded database only.

Reference :  http://www.symantec.com/docs/TECH162730

After successful SEPM upgrade plan for SEP client upgrade. If clients are high in number plan it in phase wise.

Auto upgrade can be easiest way to upgrade existing clients.

Check these article also:

Upgrade or migrate to Symantec Endpoint Protection 12.1.5

http://www.symantec.com/docs/TECH224034

http://www.symantec.com/docs/TECH207274

Is there any update?

Or

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