5.8.2 Backup operation in units of physical disk

VxVM volumes are backed up in units of the physical disks that constitute each VxVM volume.

When backup is performed in units of physical disks, disk group integrity must be maintained. Therefore, all the physical disks in the disk group must be operated synchronously.

Note

Before starting this operation, be sure to understand the basic operation of the physical disk units that constitute each VxVM volume.

For information about basic operations, refer to "Backup operation for each physical disk in the disk group" under "VxVM Volume Operation" in the "ETERNUS SF AdvancedCopy Manager Operator's Guide" for the relevant operating system.

5.8.2.1 Executing backup

It is necessary to perform the operation by synchronizing all physical disks in the disk group.

Perform the required pre-processing or post-processing work for each volume group before and after (respectively) the backup operation. Disable pre-processing and post-processing when operating individual physical disks.

Backup to both disk and tape

For backups to both disk and tape, if the Storage Server restarts while data is being written, the transaction volume and the backup volume will both have the same configuration, and an inconsistency with VxVM will occur when the Storage Server starts. Accordingly, use the following procedure to create a backup log if backups are being made to both disk and tape.

Execute the pre-processing for backup to disk.
Execute 11.2.2.1 acmbackup (Backup command) by specifying "DISK" for -m option.
Execute the post-processing for backup to disk.
Execute the pre-processing for tape copy.
Execute 11.2.2.2 acmtphistcopy (Tape copy command).
Execute the post-processing for tape copy.

Backup to tape

The table below summarizes the pre-processing and post-processing work to be performed before and after the backup to tape.

Table 5.3 Pre-processing and post-processing for backup to tape
Object	Pre-processing	Post-processing
Transaction volume	1. Stop access to all logical volumes in the disk group. 2. Unmount all file systems in the disk group, if file systems are included. 3. Import the disk group.	Remount the volumes that were unmounted by pre-processing, if file systems are included.

Backup to disk

For information about backing up to disk, refer to "Backup operation for each physical disk in the disk group" under "VxVM Volume Operation" in the "ETERNUS SF AdvancedCopy Manager Operator's Guide" for the relevant operating system.

5.8.2.2 Executing tape copy

To perform this operation, synchronize all physical disks in the disk group.

Perform the required pre-processing and post-processing work for each volume group before and after (respectively) the tape copy operation. Disable pre-processing and post-processing when operating individual physical disks.

Note

Before making tape copies, reconfigure the disk group for the backup volume. This is necessary because if a tape copy is made from a backup volume where the disk group has not been reconfigured and the Storage Server restarts during the tape copy, the transaction volume and the backup volume both have the same configuration, and an inconsistency with VxVM will occur when the Storage Server starts. (In cluster system environment, this event will occur when the node fails over.)

The table below summarizes the pre-processing and post-processing work to be performed before and after the tape copy.

Table 5.4 Pre-processing and post-processing for tape copy
Object	Pre-processing	Post-processing
Backup volume	1. Stop access to all logical volumes in the disk group. 2. Unmount all file systems in the disk group, if file systems are included.	Remount any volumes that were unmounted by pre-processing.

5.8.2.3 Executing restoration

To perform this operation, synchronize all physical disks in the disk group.

Perform the required pre-processing and post-processing work for each volume group before and after (respectively) the restoration. Disable pre-processing and post-processing when operating individual physical disks.

Note

Only backup histories made by the following methods indicated can be restored.

Restoration from tape

The table below summarizes the pre-processing and post-processing work to be performed before and after restoration from tape.

Table 5.5 Pre-processing and post-processing for restoration from tape
Object	Pre-processing	Post-processing
Restoration destination volume	1. Stop access to all logical volumes in the disk group. 2. Unmount all file systems in the disk group, if file systems are included. 3. Deport the disk group.	1. Reconfigure the disk group. (*1) 2. Remount the volumes that were unmounted by pre-processing, if file systems are included.

*1: For the reconfiguration requirements of the disk group, see the table below.

Table 5.6 Reconfiguration requirements of the disk group
Making method of backup history on tape	Restoration destination	Reconfiguration of disk group
Backup to tape directly	Transaction volumes	Not required
Backup to tape directly	Volumes other than transaction volumes	Required
Tape copy	All volumes	Required

Restoration from disk

For information about restoring from disks, refer to "Backup operation for each physical disk in the disk group" under "VxVM Volume Operation" in the "ETERNUS SF AdvancedCopy Manager Operator's Guide" for the relevant operating system.