Methodology for performing Dissimilar System Restore (DSR) for UNIX servers

Methodology for performing Dissimilar System Restore (DSR) for UNIX servers

Article: 100019012
Last Published: 2015-08-04
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Product(s): NetBackup

Problem

Methodology for performing Dissimilar System Restore (DSR) for UNIX servers

Solution


The function of Dissimilar System Restore (DSR) for UNIX clients is not a published supported function of the Bare Metal Restore (BMR) Option to NetBackup at any release level.  However, given the proper restore environment, the BMR restoration process should work without error.  It must be noted that this is still not a fully supported function and your results may be unpredictable.

The basic premise of a BMR restore of a UNIX server is that the image backed up by the source server will be restored to the target hardware exactly and unchanged.  As such, the image file used for the restore and the hardware system being restored to must be completely compatible.  The addition of missing software or device drivers is not possible during the BMR restore process. Although such software may exist in the Shared Resource Tree, it is used only for purposes of allowing the restore to occur and complete.  No portion of the SRT is used to modify installed software on the restored client. The SRT itself isgeneric in nature and no client specific information is kept in it. Please refer to the Bare Metal Restore 6.0/6.5/7.0/7.1 System Administration Guide for functional details described below.

Steps to take for a DSR for UNIX client system:
 
1.  Create a copy of the source machine's 'current' configuration
2.  Gather the target hardware configuration by performing a “ Prepare To Discover” operation on the target hardware followed by a 'Discovery' boot.
3.  Edit the “Networking Interfaces” section of the copied configuration. Change the MAC address information to match what is on the target hardware system. If desired, changes can be made to the IP-address in the configuration.  However, the host name can not be modified. Any changes to the IP-address must be reflected for host name and IP-adress resolution on any NetBackup server used for the restore operation. See the Note below.
4. Using the new copy of the configuration, edit the 'Volumes' section and use the discovered configuration to display the target disks.  This is done with the use of the 'Initialize' button.
          a.  All of the discovered disks will be found under the "Empty Disks" tab of the selection panel.
b. All of the new disks will be set to 'restricted' by default. All target disks must first have their restriction removed before slices/logical partitions/file systems can be created and allocated n them.
c. Map all required disk spaces for the restore operation to the new disk layout. The recommended method is to first choose 'Disk view' tab in the panel.
d. After choosing the 'Empty disks' selection, you will see all of the disks that were seen on the target hardware, with their device paths and sizes.
e. Right click on each desired disk and choose 'remove restriction' action.
f. Once complete move up the section and expand them until you get a 'Disks" option. Select it.
g.  Starting with the system disk, right click on the disk name and size bar and choose to map the disk.
h.  The Disk Mapping Wizard will start. Hit the 'next' button  and continue to the disk selection panel.
i.  From the set of availalbe disks choose one that will be the target of that restore operation. Continue on until all desired disks have been mapped.
j. Save off the new disk layout data.
5. Verify/Modify the 'Hosts' section to ensure that the entries are valid. Save off any changes made.
6. For performing DSR of RHEL 7.x clients, perform following additional steps on the master server:
 
a. Download the attached file “bmrepadm_postrestore”  and rename it as <ClientName>_postrestore. This "ClientName" should be same as the name appearing in "Bare Metal Restore Clients" list in NetBackup console.
b. From the command prompt, cd to the .../netbackup/bin directory and execute the following command:
/bmrepadm –add <path to script>/<ClientName>_postrestore
c. While performing Prepare To Restore for this configuration, enable the checkbox “Run external procedures”.
d. After the recovery of the client is completed on the target hardware, from the command prompt, access the netbackup/bin directory and execute the following command:
./bmrepadm –delete <ClientName>_postrestore

Note: Do not edit the bmrepadm_postrestore script. For more information about external procedures refer “About external procedures” section from the Bare Metal Restore Administrator's Guide.

Once the restore configuration has been updated to match the target hardware environment, perform a “Prepare to Restore” operation, specifying the updated restore configuration name.  Once completed, initiate a normal BMR restore operation.

Note:

The BMR restore operation and configuration information operates with registered BMR clients only.  The client host name information is part of the restore configuration and can not be modified by BMR during processing. This can cause a network environment where there are two servers with the exact same host name on the same network segment. Care must be taken to avoid this.

Client ip-address information can be modified in the 'Network Interfaces' section.  However, all NetBackup servers being used for the restore operations must have host name/ip-address resolution that matches what is in place in the BMR configuration.

Lastly, BMR is not intended to be used as a provisioning/cloning tool.  The creation of exact system duplicates can be a violation of software licensing agreements in place for any given server. Also, any CPU based or locked licensing for restored applications must be accounted for after the BMR restore completes. BMR can not perform such activities.
 
 

 

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