Example 2 (using the mirror disk facility)

This example assumes that data is mirrored using the Logical Volume Manager (LVM) and a mirror facility (it is assumed that the reader is familiar with LVM). For details on data mirroring using LVM and execution of online backup through logical volume partitioning, see the appropriate HP-UX manual. The following figure shows an example of backup using a mirror facility.

To avoid input/output contention between the backup disk and the online disk when mirroring is used, separate the I/O channels.

Figure 6-3 Example of backup using a mirror facility

[Figure]

The two RDAREAs rdarea01 and rdarea02 are backed up while HiRDB is running.

Organization of this subsection: (1) Using the pdhold command to back up and hold the RDAREAs to be backed up; (2) Swapping the system log files; (3) Partitioning the mirrored logical volume; (4) Using the pdrels command to release backup and hold of RDAREAs; (5) Making the backup from the offline logical volume

(1) Using the pdhold command to back up and hold the RDAREAs to be backed up

 
pdhold -r rdarea01,rdarea02 -b -w

Explanation: -r: Specifies the RDAREAs to be backed up.; -b -w: Specifies reference-possible backup hold (update WAIT mode).

(2) Swapping the system log files

(3) Partitioning the mirrored logical volume

(4) Using the pdrels command to release backup and hold of RDAREAs

(5) Making the backup from the offline logical volume

The backup is made from the offline logical volume. When a mirror facility is used to make a backup, backup-hold occurs only during logical volume partitioning. Therefore, the amount of physical log information for the pages to be output is reduced.

Remarks: When the automatic log unloading facility is being used, execute the pdlogatul command to record the unload log file name that corresponds to the current system log file.

6.7.3 Example 2 (using the mirror disk facility)

(1) Using the pdhold command to back up and hold the RDAREAs to be backed up

(2) Swapping the system log files

(3) Partitioning the mirrored logical volume

(4) Using the pdrels command to release backup and hold of RDAREAs

(5) Making the backup from the offline logical volume