Nonstop Database, HiRDB Version 9 System Operation Guide

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11.3.1 Moving a unit while HiRDB is running

Move a unit of a HiRDB parallel server configuration. The following figure illustrates the procedure:

[Figure]

Use of the system reconfiguration command (pdchgconf command) eliminates the need to terminate HiRDB normally. Note that HiRDB Advanced High Availability must be installed in order to use this command.

Notes
  • You cannot move a system manager unit.
  • The disk on which you create the system files and the RDAREAs for the unit to be moved must be shared by means of a SAN or other storage network system between both the current server machine and the new server machine.
  • You can move a unit only if you are using the HP-UX or AIX edition of HiRDB. This is because OS commands must be used during the configuration change to disconnect and connect the shared disk, which means that units can be moved only on operating systems that provide such commands (HP-UX and AIX).
Organization of this subsection
(1) Deploy a new server machine
(2) Prepare shells for disconnecting and connecting the shared disk
(3) Create updated HiRDB system definitions
(4) Use the pdconfchk command to check the updated HiRDB system definitions
(5) Use the pdchgconf command to modify the HiRDB system definitions
(6) Modify client environment definitions

(1) Deploy a new server machine

Deploy a new server machine, and install and set up HiRDB. For details about installing and setting up HiRDB, see the HiRDB Version 9 Installation and Design Guide.

Check that the following are the same as in your existing units:

(2) Prepare shells for disconnecting and connecting the shared disk

Prepare the shells from which you will disconnect and connect the shared disk. Execute the shells as a superuser. For safety's sake, do not include in these shells any commands other than commands for disconnecting and connecting the disk.

Shell on current server machine
Create a shell ($PDDIR/conf/chgconf/diskdiscon.sh) containing the command for disconnecting the disk storing the system files and RDAREAs from the current server machine. The following shows an example on HP-UX:
/usr/sbin/vgchange -a n device-name

Shell on new server machine
Create a shell ($PDDIR/conf/chgconf/diskcon.sh) containing the command for connecting the disk storing the system files and RDAREAs onto the new server machine. The following shows an example on HP-UX:
/usr/sbin/vgchange -a y device-name

(3) Create updated HiRDB system definitions

Use the procedure explained below to create HiRDB system definitions that reflect the change in the unit configuration.

Procedure
  1. Create a $PDDIR/conf/chgconf directory.
  2. Copy the current HiRDB system definition files into the directory that you created in step 1.
  3. Modify the HiRDB system definitions that are in the $PDDIR/conf/chgconf directory.

(4) Use the pdconfchk command to check the updated HiRDB system definitions

 
pdconfchk -d chgconf
 

Check the HiRDB system definitions in the $PDDIR/conf/chgconf directory. If errors are detected, correct the HiRDB system definitions, and then execute the pdconfchk command again.

(5) Use the pdchgconf command to modify the HiRDB system definitions

 
pdchgconf
 

Replace the HiRDB system definitions with the updated HiRDB system definitions. At this time, the shells that you created in step (2) for disconnecting and connecting the disk are executed.

Note
If system reconfiguration processing fails, the pdchgconf command might end in an error without replacing the HiRDB system definitions. If the pdchgconf command ends in an error, check the files in the $PDDIR/conf directory.

(6) Modify client environment definitions

Check if the following operands in the client environment definitions are specified; if the front-end server (FES1) that you moved is specified in these operands, change their values as appropriate:

We recommend that after the command has executed you check whether the execution results are correct. For details on how to check command execution results, see the manual HiRDB Version 9 Command Reference.