HP Archive Backup System for OpenVMS Guide to Operations

System Backup to Tape for Oracle Databases
9.11 Troubleshooting Tips
server backups to certain drives, I suggest you do not put anything in this attribute. If you do
use this attribute, be sure you have enough drives for the number of streams in the parallel
backup.
• Setting the Maximum Saves in the Archive to a number less than the number of parallel
streams that Oracle's Recovery Manager starts. I suggest you set it at 36 and control the
number of backups from the Oracle Recovery Manager.
• Starting more parallel backups than you have tape drives. Do not start two or more parallel
backups at the same time unless you have drives available for all streams in the parallel
backups.
To illustrate the problems stated above, I will give an example of setting the Maximum Saves in
the archive to 2 and then using a Oracle Recovery Manager script that starts 3 parallel streams.
Each stream starts the backup, the first two are allowed to get a volume set and start their
backup. The third server starts up and finds that there is no volume set available at this time. It
keeps trying to get a volume set. In the mean time, the first two servers finish doing the backup.
However, the controlling server will not let them end until the third server is finished. Therefore,
they hold on to the resources: drive and volume set. The third server can not finish for lack of
resources. Any of the above problems stated above can cause this deadlock.
9.10.2 Piece Name Length Greater than 254 Characters
A piece name length greater than 254 characters is not supported. This restriction may be lifted
in subsequent versions to 511 characters for a piece name length.
9.10.3 Using RDF Drives with SBT
You can NOT use Remote Device Facility (RDF) drives when using Oracle’s tape I/O slaves.
RDF drives may be used with SBT if you are not using Oracle’s tape I/O slaves.
9.10.4 Backup with Oracle Dead Connection enabled
During backup, Oracle background server process results in access violation when "Oracle Dead
connection" detection is enabled by setting the parameter SQLNET.EXPIRE_TIME with Oracle
9.2.0.4.
To use the sqlnet.expire parameter, the 'backup_tape_io_slaves=TRUE' should be set in the
init.ora file specific to the instance and execute the backup.
This is a workaround when using RMAN and ABS SBT with "sqlnet.expire" set to a non-zero
value.
9.11 Troubleshooting Tips
This section gives you some tips that may help you troubleshoot SBT if you have problems.
9.11.1 Using the logical MDMS$SBT_TRACE_LEVEL
The logical MDMS$SBT_TRACE_LEVEL allows you define how much tracing appears in the
trace file, ORA_DUMP:SBTIO.LOG. By default any error that is detected by SBT, is traced in
the trace file. You can define the logical MDMS$SBT_TRACE_LEVEL to display more information.
The definition of MDMS$SBT_ TRACE_LEVEL is defined in SYS$STAR-
TUP:MDMS$SYSTARTUP.COM. If the logical is not defined on your system, see Section 9.3
to setup the logical.
There are only three values that you might want to use. The rest of the values are for support use.
By default the following values are enabled:
• TR_GENINFO - general information about the backup and restore. With this value defined,
you will see message about starting the backup or restore.
9-20 System Backup to Tape for Oracle Databases