This is applicable to SQL 2008 and later versions.
Many of us didn’t work on same but must have faced this question in interview. Being Sql dba you must be aware of same for both interview or for some situation where we have to change SQL cluster service account and none of seniors around.
1. Go to SQL Server active node
2. Open sql server configuration manager
3. Go to sql server services option, Select SQL instance , properties
4 change service account of sql server and click apply
5. Sql server will ask to restart. Let sql server do restart, this will not switch nodes(Active will remain active)
6. Now go to passive node
7. Open sql configuration manager
8. Go to services and check SQl service for which you have change password on active node.
9. Service account will auto reflect in passive node.
10. Do same steps for sql server agent.
11. Once done Please do failover and check sql should able to run on all passive nodes and from different servers in same domain.
Don’t forget to give all windows level permission to service account on passive nodes which you have given on active node