Backing up and restoring the system configuration

You can back up and restore the configuration data for the system after preliminary tasks are completed.

Configuration data for the system provides information about your block system and the objects that are defined in it. The backup and restore functions of the svcconfig command can back up and restore only your configuration data for the Storwize® V7000 system. You must regularly back up your file systems and your application data by using the appropriate backup methods.

You can maintain your configuration data for the system by completing the following tasks:

Backing up the configuration data
Restoring the configuration data
Deleting unwanted backup configuration data files

Before you back up your configuration data, the following prerequisites must be met:

No independent operations that change the configuration for the system can be running while the backup command is running.
No object name can begin with an underscore character (_).

Note:

The default object names for controllers, I/O groups, and managed disks (MDisks) do not restore correctly if the ID of the object is different from what is recorded in the current configuration data file.
All other objects with default names are renamed during the restore process. The new names appear in the format name_r where name is the name of the object in your system.

Contact the IBM® support center to help you prepare the Storwize V7000 Unified system to do the restoring of the system configuration on the control enclosure.

The configuration restore procedure is designed to restore the information about your block storage configuration, such as block volumes, local Metro Mirror information, local Global Mirror information, storage pools, and nodes. All the data that is written to the block volumes is not restored.

To restore the data on the block volumes, you must restore the application data separately from any application that uses the volumes on the clustered system as storage. The file volumes are not restored. You must restore the file module configuration and the file systems separately. Therefore, you must have a backup of this data before you follow the configuration recovery process.

Before you restore your configuration data, the following prerequisites must be met:

You have the Security Administrator role associated with your user name and password.
You have a copy of your backup configuration files on a server that is accessible to the system.
You have a backup copy of your application data that is ready to load on your system after the restore configuration operation is complete.
You know the current license settings for your system.
You did not remove any hardware since the last backup of your configuration.
No zoning changes were made on the Fibre Channel fabric which would prevent communication between the Storwize V7000 Unified and any storage controllers which are present in the configuration.
For configurations with more than one I/O group, if a new system is created on which the configuration data is to be restored, the I/O groups for the other control enclosures must be added.
You have at least 3 USB flash drives if encryption was enabled on the system when its configuration was backed up. The USB flash drives are used for generation of new keys as part of the restore process or for manually restoring encryption if the system has less than 3 USB ports.

Use the following steps to determine how to achieve an ideal T4 recovery:

Open the appropriate svc.config.backup.xml (or svc.config.cron.xml) file with a suitable text editor or browser and navigate to the node section of the file.
For each node entry, make a note of the value of the following properties: IO_group_id, canister_id, enclosure_serial_number .
Use the CLI sainfo lsservicenodes command and the data to determine which node canisters previously belonged in each I/O group.

Restoring the system configuration should be performed via one of the nodes previously in IO group zero. For example, property name="IO_group_id" value="0" . The remaining enclosures should be added, as required, in the appropriate order based on the previous IO_group_id of its node canisters.

Note: It is not currently possible to determine which canister within the identified enclosure was previously used for cluster creation. Typically the restoration should be performed via canister 1.

Before you begin, hardware recovery must be complete. The following hardware must be operational: hosts, Storwize V7000 Unified enclosures, internal flash drives and expansion enclosures (if applicable), the Ethernet network, the SAN fabric, and any external storage systems (if applicable).