Recovering a Database: Step-By-Step Instructions

The symptoms of media failure are as variable as the causes.

If only a single block on the disk is bad, your database may appear to function normally for some time after the corruption occurs, unless you are frequently running dbcc commands. If an entire disk or disk controller is bad. SAP ASE marks the database as suspect and displays a warning message. If the disk storing the master database fails, users cannot log in to the server, and users already logged in cannot perform any actions that access the system tables in master.

Get a current log dump of every database on the device.
Examine the space usage of every database on the device.
After you have gathered this information for all databases on the device, drop each database.
Use sp_dropdevice to drop the failed device. See the Reference Manual: Procedures.
Use disk init to initialize the new database devices. See System Administration Guide: Volume 1 > Initializing Database Devices.
Re-create the databases, one at a time.
Load the most recent database dump into each database.
Apply each transaction log dump in the order in which it was created.

The steps that require more detailed information than listed here are discussed in the following sections.

Getting a Current Dump of the Transaction Log
Use the dump transaction with no_truncate command, or the sybdumptran utility to get a current transaction log dump.
Examining the Space Usage
Determine which devices your database uses, how much space is allocated on each device, and whether the space is used for data, log, or both.
Dropping the Databases
Use drop database to drop each database.
Re-creating the Databases
Re-create each database using segment information you have collected.
Loading the Database
Reload the database using load database.
Loading the Transaction Logs
Use load transaction to apply transaction log backups in the same sequence in which they were made.
Bringing the Databases Online
After you have applied all transaction log dumps to a database, use online database to make it available for use.

Parent topic: Backing Up and Restoring User Databases