Before creating standby database, you need to consider where your standby database files will be located and make sure the filesystem has necessary paths available and pre-created.

Dbvisit will create standby database files regardless whether on ASM, Filesystem or ACFS according to the general Oracle rules and concept. The main consideration is always whether you will do file path conversion or not.

The behavior is different for OMF files and non-OMF files. If you don’t know which type of files your primary database is using, be sure to check https://dbvisit.atlassian.net/wiki/spaces/DSMP/pages/3806167060/Prerequisites#5.-Check-Primary-Database-Files-Naming-Structure

1 OMF files

Location of OMF files on standby server is completely driven by OMF parameters db_create_file_dest , db_create_online_log_dest_[x] and db_recovery_file_dest. You may change it to place your files on different ASM diskgroup, different filesystem mountpoint etc … OMF parameters on primary and standby are needed even if you don’t make any type of name/path conversion.

OMF init parameters are:

If db_create_online_log_dest_[x] is not set, Oracle creates redo in db_create_file_dest and creates automatically mirror in db_recovery_file_dest

If you have identical filesystem structure on standby and on primary (no path conversion done):

• You will need to set OMF parameters when creating standby database to the same values as on your primary. This is done automatically during create standby database wizard, so you don’t have to worry about it further.

If you would like to have different file paths on primary and standby or if you’re converting between ASM and filesystem (path conversion is done):

• You will need to set OMF parameters when creating standby database to intended locations as described further

Following rules will apply for different types of files when standby database is created:

Location of OMF datafiles and tempfiles on standby

They will be created on standby in location <db_create_file_dest>/<db_unique_name>/datafile. For example if you have OMF datafile on primary (primary db_unique_name=SOLO):

and your standby will be on filesystem with init parameters:

db_create_file_dest = /u01/app/oracle/oradata

db_unique_name=dev

then standby OMF file will be created like so:

Location of OMF redo logs on standby

They will be created on standby in location(s) <db_create_online_log_dest_[x]>/<db_unique_name>/onlinelog.

If parameters db_create_online_log_dest_[x] are not set, oracle will automatically create redo in <db_create_file_dest>/<db_unique_name>/onlinelog and its mirror in <db_recovery_file_dest>/<db_unique_name>/onlinelog.

For example if your primary has redo logs (only group 3 is displayed):

and your standby will be on filesystem with init parameters

db_create_file_dest = /u02/app/oracle/oradata

db_recovery_file_dest = /u02/app/oracle/fast_recovery_area

db_unique_name=dev

db_create_online_log_dest_[x] are not set

then standby OMF redo logs will be created like so (only group 3 is displayed):

Primary ASM to Standby filesystem conversion example with OMF files

Let’s have a look how primary ASM to Standby Filesystem conversion works for exclusively OMF primary database.

Primary database has following configuration:

During create standby database we would set OMF parameters like so:

Open

After standby database is created it will have following structure:

2 Non-OMF files

If you have identical filesystem structure on standby and on primary (no path conversion done):

There’s no need to set any specific parameters for standby database if your primary database uses non-OMF files and you have identical filesystem structure / paths on standby and on primary.

If you would like to have different file paths on primary and standby or if you’re converting between ASM and filesystem (path conversion is done):

You need to set the convert parameters for your standby database during standby database creation. There are two convert parameters to set:

The convert parameters have following properties:

• They contain pair or pairs of strings which are used for path conversion when standby database is created

• They are valid on standby database only. On primary, they are not effective.

• For Dbvisit to work properly, they need always set on primary and standby (their values are reversed)

Primary filesystem to Standby filesystem conversion example with non-OMF files

Primary database has following configuration:

On standby server we want to place all files on u02 instead of u01. So during the create standby database we would specify following parameters:

Open

After the standby database is created, files will have following configuration:

3 Mixing OMF and Non-OMF files

This configuration is very complex for standby database creation and placement of database files on standby.

If you have identical filesystem structure on standby and on primary (no path conversion done):

• You will need to set OMF parameters when creating standby database to the same values as on your primary (this is done automatically during create standby database wizard)

• There’s no need to set any specific parameters for non-OMF files

If you would like to have different file paths on primary and standby or if you’re converting between ASM and filesystem (path conversion is done):

• You will need to set OMF parameters when creating standby database to intended locations

• You will need to set db_file_name_convert and log_file_name_convert as well

Primary filesystem to Standby filesystem path conversion example with OMF and non-OMF mix:

Primary database has following configuration:

All files are OMF except of one datafile (nonomf.dbf) and one redo member (redo99.log).

On standby server we want to place all files on u01 instead of u02. So during the create standby database we need to specify following parameters:

We need to specify OMF parameters and convert parameters as well, becausew we’re using OMF and non-OMF file types and we want to have path conversion.