Migrating a DS5.x topology to DS6.x using dsmig and helper scripts
By marcos on Jun 07, 2007
Migrating a complete 5.x tolopogy to a 6.x one is a task which requires to be implemented into several planned steps. The DS6.x product comes with a very useful utility (dsmig) which helps you achieve SOME of those steps, in particular, those which are instance-centric (migrating the schema, security certificates, configuration settings and even databases if the platform/OS have not changed). Or, other steps more service-centric like migration of the old replication agreements will require manual work by default.
To avoid such a manual work, I have put in place both a topology migration strategy which is explained in a Migration Cookbook and a set of migration helper scripts to automate the migration of a complete topology, both instance-centric and service-centric.
If you are a Sun Field Engineer and you are interested for the migration CookBook and the helper additional scripts (which are aimed to drammatically decrease the topology total migration time), don't hesitate to contact me.
As a simple summary, here is what can be said at this stage about the topic:
Here is the basic strategy to migrate a complete topology that I envision inside the migration CookBook:
1. Individual LIGHT migration of each instance inside the topology (LIGHT = migrate schema, security DB and configuration but NOT the instance DBs)
2. Individual database migration of each instance inside the topology
3. Fix-up of all configuration references to the old topology and replace them by references to the new topology (for example, references to old replicas in the replication agreements)
Step 1 above is already assured by the default dsmig utility delivered in 6.x. In other words, running the official dsmig with the appropriate commands should be enough to achieve the task... Nevertheless, I have written a dsmig-light.sh script on top of dsmig that will help automate step 1 further if required.
Step 2 needs to be run with care, it may be easier or more difficult depending on the changes in the OS or the platform during the migration. There are different possible scenarios requiring different actions (dsmig, import/export with -r, import/export without -r....). The CookBook describes all the possible scenarios and provides the appropriate actions/commands to execute.
Step 3 is achieved by running the helper script dsmig-topology.sh, which can be obtained through Sun Support as mentioned above.
One final important recommendation: if you are really intending to use all this material to help you with your customer topology migration, please make sure the topology migration is happening towards 6.1 or onwards. Indeed, the DS6.1 code has been enhanced to take into account the possibility to launch service-centric scripts like the dsmig-topology.sh required in Step 3.