SEP sesam Server Disaster Recovery
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|Welcome to the latest SEP sesam documentation version 4.4.3/4.4.3 Beefalo V2. For previous documentation version(s), check Documentation archive.|
A computer disaster refers to a system failure, disk drive failure or other severe occurrence that renders user data on the computer inaccessible. To recover from such a disaster, data from SEP sesam's Server is used to restore the system to a working state.
Note that standard backup does not prepare for disaster recovery. Disaster recovery (DR) involves a set of procedures that enable the recovery of vital technology infrastructure and systems following a computer disaster. During the process, server data from saveset is recovered and restored to the system.
SEP sesam provides three types of disaster recovery solutions:
This section describes the disaster recovery strategy, requirements, and procedure for the SEP sesam Server self-recovery process.
How does the SEP sesam self-backup work?
To prepare for a possible breakdown of the SEP sesam Server, you need to perform a self-backup of the SEP sesam installation. This means that you have to configure at least one backup task named SESAM_BACKUP. This will back up SEP sesam's var directory, including all listings, log files, database, and INI-files. This backup should be run daily, either in COPY or FULL mode. For details, see Preparation for Disaster Recovery below.
Additionally, a disaster interface must be properly configured to help carry out the disaster recovery process: sm_disaster (Linux) or sm_disaster.cmd/sm_disaster.ps1 (Windows). The disaster interface sends an email describing the disaster recovery procedure and an attachment containing the SEP sesam bootstrap database with all the essential data for disaster recovery. For details on how to activate this interface, see Preparation for Disaster Recovery below.
The self-backup procedure consists of the following:
- When the SEP sesam self-backup starts (SESAM_BACKUP), the entire SEP sesam database is exported to the path <SESAM_ROOT>/var/<db>[_pg]/backup. The export files have names such as sesam_db_20121223-20121224060003.sql.gz and are backed up to a pre-defined media pool. It is recommended that you configure a SEP sesam DR-dedicated media pool for storing all of your SEP disaster recovery savesets.
- Every time SESAM_BACKUP is executed, a bootstrap file of the SEP sesam database (for example, sesam_bootstrap_db_[datetime].sql.gz) is exported to the <SESAM_ROOT>/var/db[_pg]/backup directory. This file contains the SEP sesam configuration and data history of SEP sesam self-backups for the last 30 days.
- sm_disaster copies the contents of input arguments (DISASTER or SESAM_BACKUP) from the SEP sesam Server to predefined locations on another computer (emails, copies of files, etc.). Information about SEP sesam's last disaster backup is also stored.
- Finally, an email with a short recovery description and the bootstrap file as attachment are sent regularly to the email address you configured. The bootstrap export is used exclusively for SEP sesam system recovery in the event of a disaster, therefore you should save every version of this file to a safe location.
Preparing for Disaster Recovery
For general details on configuring a backup and its prerequisites, see Standard Backup Procedure. Here only disaster recovery specific information is introduced.
To fully utilize disaster recovery's functionality and ensure that all disaster-related information is generated and sent, the following steps must be carried out:
- The backup task SESAM_BACKUP is usually configured after the installation of a SEP sesam Server. Hence it should already be present. If it is not, you have to configure it:
Open the GUI and from the Main selection -> Tasks -> By Clients -> select your SEP sesam Server -> New Backup Task. The name of the backup task must be SESAM_BACKUP. It typically includes the <SESAM_ROOT>/var and <SESAM_ROOT>/bin/sesam directories and excludes the work and log directories. Click OK to save the task.
- Once your disaster recovery task is configured, set up a backup schedule (GUI -> Scheduling -> Schedules). The SEP sesam backup should run at a time when no other activities are running in the SEP sesam environment. It is recommended to run this task every day. For details on scheduling, see Creating a Schedule.
- Create an event to be linked to the schedule. Select the backup level COPY. It is recommended that you select a disaster recovery dedicated media pool for storing all your disaster recovery savesets. For general information on creating a backup event, see Creating a Backup Event.
- Activate the sm_disaster interface: From the SEP sesam GUI menu, select Configuration -> Interfaces -> Disaster Interface. A window with the interface script is displayed.
- Click Save to confirm the dialog. The sm_disaster file is read and stored in the directory <SESAM_ROOT>/bin/sesam.
Tip: After installing SEP sesam, the file sm_disaster (Linux) or sm_disaster.cmd/sm_disaster.ps1 (Windows) is located in the <SESAM_ROOT>/skel/templates/ directory. Alternatively, you can activate the disaster interface by copying sm_disaster from <SESAM_ROOT>/skel/templates to <SESAM_ROOT>/bin/sesam.
Note The sm_disaster file has been completely redesigned for SEP sesam version 4.4.2. If your SEP sesam Server version is 4.4.2 or lower, you must replace the sm_disaster file after updating to SEP sesam Server 4.4.2:
- Windows: The MSI Installer will ask you if the existing interface should be overwritten. Choose <yes> to overwrite the existing interface. Alternatively, copy <SESAM_BIN>/skel/templates/sm_disaster.ps1 to <SESAM_BIN>/bin/sesam/sm_disaster.ps1.
- Linux: Copy <SESAM_BIN>/skel/templates/sm_disaster to <SESAM_BIN>/bin/sesam/sm_disaster to get the latest version of the disaster interface.
- Configure the SEP sesam email for the sesam account so that the interface sends messages after self-backup: From the GUI menu, select Configuration -> Email Settings -> New. An Email Account window is displayed.
- In the Account field, type the name sesam (it must be written in lowercase).
- Optionally, enter the name in the Customer field.
- Enter the name of the sender (the name of the respective SEP sesam Server).
- In the SMTP server field, enter the name or IP-address of the outgoing mail server.
- In the SMTP user field, enter the user name for the SMTP server. If the SMTP user name is not specified, the SMTP server presumably does not require authorization.
- If the mail server requires authentication, enter the password in the Password field.
- Optionally, specify the SMTP port.
- In the Recipient field, enter the address of the recipient of the DR notification emails. Typically, this is the backup administrator's address.
- Optionally, specify additional recipients in the CC and BCC fields.
Recovering SEP sesam from disaster
Once configured, the disaster interface sends an email describing the disaster recovery procedure in the event of a disaster and an attachment containing the SEP sesam bootstrap database with all the essential data for disaster recovery. Disaster recovery is executed by inspecting all backups containing DISASTER or SESAM, from which you select the last known good copy of the data and restore it.
The following procedure describes the disaster recovery process for a SEP sesam Server. Before you reinstall the SEP sesam Server and start the actual recovery, perform the following step on both Linux and Microsoft Windows:
- Connect the backup storage hardware to the new SEP sesam Server. The components will be detected and pre-configured during the SEP sesam Server installation.
|It is absolutely necessary that the GUI is started as superuser Administrator and that the checkbox Disaster Recovery is selected in the restore wizard (see steps below), otherwise the recovery will fail!|
- Save the bootstrap file (obtained via email through the sm_distaster interface) to the SEP sesam Server you want to recover.
- Depending on your operating system, install a SEP sesam Server as follows:
- Double-click the SEP sesam Server installation file. Agree to the license agreement and check the Disaster recovery box when the first dialog appears.
- Continue the installation until you get to the last step Ready to Install SEP sesam Server version <number>. Under the option Import SEP sesam Server database, click Browse and select the bootstrap file you have saved locally on the server, and then click Install.
- Download and install the SEP sesam Server package.
Note The restore is performed with additional relocation logic for the database backup file which was created during SESAM_BACKUP. This file will be restored to gv_rw_db:restore.
- After importing the bootstrap data, SEP sesam should have the basic configuration as before (for example, all existing drives). However, you should verify the following on your newly installed Linux server:
- Check the system settings to ensure that the restored SEP sesam configuration conforms to the current server environment (library and drive device names, disk partition device names and mount points, etc.). If not, the SEP sesam settings must be adjusted.
- If recovery is being executed from physical media, open the GUI and perform a SEP sesam archive adjustment to update the SEP sesam media information with the physical tape library: Main selection -> Components -> Loaders -> select a loader -> click Archive Adjustment. For details, see Setting up Archive Adjustment.
- Start the SEP sesam GUI as superuser Administrator and from Main selection -> Job State -> Backups select the latest SESAM_BACKUP, right-click it and select Restore. The restore wizard is displayed.
- In the Select Task window, check the Disaster restore checkbox and click Next. Only if the the Disaster restore option is set, the restore will be performed with the parameters that lead to a successful recovery.
- In the Target Settings window, make sure that the default settings Restore to original target path and Overwrite existing items are selected.
- Click Next and then Start to start the restore.
- When the restore is finished, the dialog Complete the disaster restore appears asking if you want to import the database automatically. Confirm with OK.
|You have to download and install the same SEP sesam Server package that was installed on the old system. It is important to provide the same operating system environment as that of the original server, therefore set up the new server system in the same way as the previous one (same hostname, same IP address). For Linux, follow the installation procedure described in Installing Linux Server package.|
|The GUI will lose the connection to the UI server.|
|Disaster recovery can also be started from the toolbar via the Disaster recovery icon if you have activated the SEP sesam disaster recovery key in the menu bar -> Configuration -> Defaults -> Settings tab by setting the value for disaster_recovery key to one (1).|
|The restore is performed with additional relocation logic for the database backup file which was created during SESAM_BACKUP. This file will be restored to gv_rw_db:restore.|
This will load the database export file located under gv_rw_db:restore. Additionally, the result of the SESAM_BACKUP restore will be imported into the SEP sesam database.
|The GUI will lose the connection to the UI server.|
After restarting the SEP sesam GUI, the system is again operational with the data backed up in the last SEP sesam self-backup.
Alternative recovery procedure using command line
Typically, an email sent by the disaster interface should have the SEP sesam bootstrap database file attached. If there is no attachment, you can still perform a disaster recovery by running restore from the command line. You can find the required arguments in the disaster email, namely, the label of the media currently being used and the complete restore command, which restores the data from the attached savesets bootstrap database file.
- Identify the location containing SEP sesam's last disaster backup and copy the restore command, located at the very end of the disaster email. Make sure you set the profile first. For details, see What happens when I set a profile?
- If the sesam backup is located on physical media (e.g., a tape), load the appropriate medium into the drive.
After the recovery
Make sure that the hardware is correctly connected and then run a test backup and restore to the devices.
Some backup results may appear faulty in the job status views. This is because a certain amount of time passes between the last self-backup and the recovery time. Some scheduled jobs did not run because the SEP sesam Server was not available at the time. The number of errors displayed depends on how long the SEP sesam Server was unavailable and on the number of scheduled backup jobs.