The following figure shows the procedures for backing up mirror volumes through snapshot by slice detachment.
Figure 7.38 Backup Operation (by Slice Detachment)
This section describes the procedure for creating backup of a mirror volume making use of a snapshot by detaching a slice. This method requires the following "slice operations."
Detach Slice
Attach Slice
Information
Reliable Backup Procedures
Although the procedure above allows you to use the volume as it is after preparing backup, reliability is affected since one of the slices is excluded.
To ensure reliability, temporarily add a backup disk and perform synchronization copying. After its completion, exclude the slice.
For safe and reliable backup, follow the procedures below.
Register backup disk with class.
Connect backup disk to group.
After completing synchronization copying, stop service.
Detach slice.
Resume service.
Perform backup using access path for backup.
Attach slice.
Disconnect backup disk from group.
Remove backup disk from class.
Completing procedures 1. and 2. in advance will save the waiting time for synchronization copying in procedure 3., therefore reducing the time required for backup.
Note
Perform [Detach Slice] after Stopping Services
To ensure integrity of backup data, always stop service before excluding the slice.
You may resume service once [Detach Slice] is complete. You do not have to suspend service during the actual backup process.
When excluding the slice without stopping service, run host programs such as fsck (in case of file system) as necessary.
Slice Detachment
In order to create a backup, you must temporarily exclude one of the slices from volume, and make it accessible as a separate volume.
The procedures are explained below.
Displaying the volume status including the slice
In the Main screen, display the volume containing the slice for which you want to create a backup. Click the icon and [Slice Information] appears.
Selecting the slice to detach
In the Slice List, select the slice you want to detach by clicking its icon.
Selecting [Detach Slice] menu
In the Main screen [Operation] menu, select [Detach Slice].
Figure 7.39 Detach Slice
Setting the environment of the detaching slice
We will set the environment of the detaching slice.
Figure 7.40 Setting the environment of the detaching slice
Access Mode
Set the access mode of the detached slice.
The initial value is "Read and write possible."
When you specify "Read only possible," the detached mirror slice will be available for read only. Opening a read-only slice in write mode will result in an error.
Click <OK> after setting the environment. If you click <Cancel>, the detaching of the slice will be canceled.
Note
Slice status available for [Detach Slice]
You can only perform [Detach Slice] operation to slices that are in either "active" or "stop" status.
The confirmation screen shown below appears.
To continue the process, click <Yes>. Clicking <No> cancels the slice detachment process.
Figure 7.41 Confirming Slice Detach
Backup Using Access Path
Click <Yes>, and message notifying the completion of detach slice appears.
Use the access path specified in the message to proceed with backup.
Figure 7.42 Notifying Detach Slice Complete
Attach Slice
After the backup is complete, the slice that was temporarily detached will be attached to the volume again.
If the volume is activated, synchronization copying will begin.
The procedures are explained below.
Selecting the slice to attach
In the Slice Information field, select the mirror slice you want to attach by clicking its icon.
Selecting [Attach Slice] menu
In the Main screen [Operation] menu, select [Attach Slice].
Figure 7.43 Attach Slice
The confirmation screen shown below appears.
To continue the process, click <Yes>. Clicking <No> cancels the slice attachment process.
Figure 7.44 Confirming "Attach Slice"
Notifying the completion of Attach Slice
Click <OK>, and a message notifying the completion of Attach Slice appears.
Figure 7.45 Notifying Attach Slice Completion
Stop/Activate Slice
Stop Slice
In order to protect data of the slice which has been detached to prepare for backup, a slice with "temp" status will temporarily become inaccessible.
Selecting the slice to stop
In the Slice Information Field, select the slice you want to stop by clicking the "temp" status slice icon.
Selecting [Stop/Activate Slice] menu
In the Main screen [Operation] menu, select [Stop/Activate Slice].
Figure 7.46 Stop Slice
To continue the process, click <Yes>. Clicking <No> cancels the slice stop process.
Activate Slice
Reactivate the slice that has become inaccessible ("temp-stop" status) as a result of performing [Stop Slice] operation or switching of the nodes, and make it accessible.
Selecting the slice to activate
In the Slice Information Field, select the slice you want to reactivate by clicking the "temp-stop" status slice icon.
Selecting [Stop/Activate Slice] menu
In the Main screen [Operation] menu, select [Stop/Activate Slice].
Figure 7.47 Activate Slice
To continue the process, click <Yes>. Clicking <No> cancels the slice activation process.
