Restoring Certificate Services from Backup
The following scenario shows how the Certificate Services backup functions can be used to restore and recover a Certificate Services database and its associated files. The restoration process involves writing the files contained in a backup set to disk. You may restore multiple backup sets (one full backup plus zero or more incremental backups), but all restores must be complete prior to beginning the recovery process. The recovery process involves Certificate Services replaying log files to ensure database and log file consistency, thereby ensuring database integrity. The scenario illustrates the function calls to restore the backup sets and inform Certificate Services of the recovery parameters.
An existing full backup of the Certificate Services database must exist before implementing this scenario.
- Load the Certadm.dll library into memory (by calling LoadLibrary).
- Retrieve the address of each of the necessary functions in Certadm.dll (by means of GetProcAddress). Use these addresses when calling the functions in the remaining steps.
- Call CertSrvIsServerOnline to determine whether Certificate Services is online. If Certificate Services is running, shut it down before proceeding. Certificate Services must not be online for the restore operations to be successful.
- Call CertSrvRestorePrepare to begin a restore session. The resulting Certificate Services backup context handle will be used by several of the other functions.
- Determine the path for the database location. During a backup scenario, this value would have been available from a call to CertSrvRestoreGetDatabaseLocations; this value should have been stored as part of the backup.
- Create a restore map specifying the name of the restored database. A Certificate Services database restore map structure (CSEDB_RSTMAPW) is used to specify a restore map. Set the CSEDB_RSTMAPW's pwszDatabaseName member and the CSEDB_RSTMAPW's pwszNewDatabaseName member to the database location determined in step 5. Optionally, if the restored database is to have a different name than the backup database, set the CSEDB_RSTMAPW's pwszNewDatabaseName member to the new database name.
- If you want to ensure that modifications made to the database after the backup was performed are not reapplied after database restore is complete (as part of database recovery performed during the next Certificate Services startup), delete files from the target server's active database and log directories.
- Copy the files contained in the full backup to the target server's active database and log directories.
- Call CertSrvRestoreRegister to register a restore operation for the full backup. CertSrvRestoreRegister uses the restore map specified in step 6. CertSrvRestoreRegister also specifies the location of the backup database and logs. Calling CertSrvRestoreRegister will force Certificate Services to attempt a restore operation the next time it is started. It also prevents Certificate Services from processing Certificate Requests until the restoration is complete.
- Call CertSrvRestoreRegisterComplete, thereby finishing the registration activity that started in step 8. Note that the registration of a restore operation is an instruction for Certificate Services to follow when it is started; the actual recovery will take place only after Certificate Services is started.
- For each incremental backup to be restored, copy the files contained in the incremental backup to the target server's active log directory, then call CertSrvRestoreRegister, followed by a call to CertSrvRestoreRegisterComplete. The registration of the incremental backups for restoration can occur in any order, but only the set of files for one incremental backup should be copied to the server before each call to CertSrvRestoreRegister.
- Copy the Certificate Services dynamic files to the target server. The dynamic files would have been identified during the backup when CertSrvBackupGetDynamicFileList was called. It may be necessary to stop the World Wide Web Publishing Service to allow overwriting the dynamic files.
- Call CertSrvRestoreEnd to end the restore session.
- Start the Certificate Services application manually (or wait until the next restart for it to start automatically). When Certificate Services starts, it will determine whether a restore operation has been registered; if a restore operation has been registered, Certificate Services will begin the recovery. Certificate Services will not process any certificate requests until the recovery operation is completed.