How do I perform a selective restore from an image backup using Legato NetWorker?

Issue

How do I perform a selective restore from an image backup using Legato NetWorker?

Solution

NOTE: Before reading this article, Mirapoint highly recommends reading the latest version of the Mirapoint Backup and Restore Guide.

Before you can selectively restore individual folders and their content from your NDMP image backup, your Legato configuration must be set up so that a history file is created at the time of the backup. Follow the instructions in Modifying Legato NetWorker for NDMP Selective Restore from Image before proceeding with your backup and restore.

How does selective restore work? Selective restore is used to restore mail folders and the messages in them. It does not over-write the contents of a folder, instead, it copies the restored data to a staging area, and from there it is merged with the current content of that mail folder; calendar preferences, filters, and address book are over-written in the restore.

Unlike a full restore or system recovery, all restored messages in a selective restore are marked as unread, regardless of their status when the backup was made.

How you select what to restore is critical to the success of the restore. Understanding Mirapoint's Message Store for Selective Restore from Image Backup provides information on the message store and file structure used by Mirapoint and will help you better understand selective restore.

This procedure assumes you are running NetWorker 7.1 on a Solaris workstation.

Using nwrecover to Perform a Selective Restore

Start nwrecover. Enter either of the following commands:

CLI> nwrecover &

or

CLI> # nwrecover -c mirapointhostname

Where mirapointhostname is the name of the client you want to restore. If you use this command you do not have to change the client, and skip to "Selecting the User Data" in this article.

The nwrecover main window displays.

Figure 1 Nwrecover Main Window

Selecting the Client

If you specified the hostname of a client for which you want to recover data when you launched nwrecover, skip this step.

The client is the Mirapoint system you backed up, and now want to restore.

To select the client, do the following:

Figure 2 Nwrecover Change Menu

1. Click Change (located in the top menu bar). From the pull down menu, click Client (see Figure 2 above).

The Change Client pop-up window displays (see below).

Figure 3 Nwrecover Change Client Pop-Up Window

2. Click Update Client List to display the list of available clients.

3. Click on the client you want to use for the restore, then click Ok.

The Change Client pop-up window closes, and leaves you back at the Main Menu. The display changes to reflect the client you selected.

Selecting the User Data

To select the data you want to restore, do the following:

Figure 4 Nwrecover Tree Menu

1. Expand the file history to reveal the files available for you to recover. To do this either click on Tree on the top menu bar, or double click on the file icon in the lower left pane (see Figure 4 above).

If you click Tree, then click Expand One Level, you can selectively reveal the files you want to see one level at a time, or click Expand Branch to reveal all files for that client.

For more information on the file hierarchy of the Mirapoint message store and selective restore, see Understanding Mirapoint's Message Store for Selective Restore from Image Backup.

2. Mark each directory and/or file to be restored. Use any of the following methods:

• Highlight the file or directory, then click Mark. (Click Unmark to deselect the file or directory).
• Highlight the file or directory, click Mark on the top tool bar, then select Mark pull-down list. (To deselect, repeat this procedure and click Unmark instead of Mark).
• Click the check-box adjacent to the file or directory. (To deselect, click the check-box again).

See the data range for more information on how to correctly select files and directories for a successful selective restore

Figure 5 Nwrecover /usr/store File Hierarchy Example

Individual user mail folders (mailboxes and content) are filed in the message store under the /usr/store/spool/user directory. The contents of a selected directory displays in the pane on the right side of the screen.

When selecting data for the restore, you have two options:

• Restore a folder (directory) with all its content (safest method)
• Restore folder (directory) content but not the folder

To restore a user's folder with all of its contents, click on the check box for the folder to be restored in the pane on the left side of the screen (see Figure 5 above). That folder's contents are automatically checked, and the check box beside the entire directory pathname for that folder is also checked. 

To deselect any element of the folder you do not want to restore, click on the check box beside the individual items to be omitted; the check mark is removed. 

To restore the contents of a folder but not the folder itself, expand the directory structure to reveal the desired folder, then click on the check box next to the message IMAP ID, or subfolder in the right side pane. A check mark appears in that pane. The file hierarchy in the directory structure (left side) pane displays a check mark of that element's pathname. The most useful data files to selectively restore are:

• For WebMail: hdr.db, var.db, wmprefs.var
• For Calendar: mcal.db
• For Address Book: addrbook.var, addrbook.ldif

Note: If you use this method to selectively restore data, it might not provide the intended result. It is safer and less problematic to restore a folder with all its content.

To selectively restore a user's calendar, but not the entire folder, you must select the mcal.db and prefs.txt files, or the restore will fail, and data will be lost.

Selecting the Browse Time

If you are restoring from the most recent backup, you do not have to select a browse time.

To select the browse time for the records you are restoring, do the following:

1. Select Browse Time from the Change menu. The following dialog_popup window displays (see Figure 6 below).

Figure 6 Nwrecover Change Browse Time Dialog Pop Up Window

2. Click Ok to display the Change Browse Time pop-up window. (see Figure 7 above).

Figure 7 Nwrecover Change Browse Time Pop Up Window

3. Click the day(s) to specify the restore data date range. Click the Next or Previous buttons to change from the current month.

4. Click OK.

Starting the Restore

To start the restore, do the following:

1. Click the Start icon or Click File in the top menu bar, then click Start Restore (see Figure 8 below).

Figure 8 Nwrecover File Drop-Down Menu

The Conflict Resolution pop-up window displays (see Figure 9 below).

Figure 9 Nwrecover Conflict Resolution Pop-Up Window

2. Make any desired modifications, then click Ok.

Each option should be self-explanatory. For more information on each option in the Conflict Resolution pop-up window, click Help.

The Start Dialog_popup displays (see Figure 10 below).

Figure 10 Nwrecover Dialog_Popup Window

3. Click Ok to close this dialog box and begin the restore.

The Recover Status pop-up window displays (see Figure 11 below). This window provides the current status of the recover throughout the process. If the recover fails for any reason, an error or status message displays in this window.

Figure 11 Nwrecover Recover Status Pop-Up Window

To cancel the recover at any time, click Cancel.

Completing the Selective Restore

The NetWorker DMA completes the transfer of user records to a staging area on the Mirapoint system. The Mirapoint system then begins a merge of the selected files, and incorporates the user data into its file system. The restore of user data is not complete until this merge occurs.

To check on the status of the NDMP merge, use the Ndmp Merge Status command. You can have the Mirapoint system send you an email when the merge completes by adding your email address to dl-backup-status.

To clear out the status of this restore, use the Ndmp Merge Clear command.

To abandon the merge process, use the Ndmp Merge Abort command. If you execute this command you cannot restart the restore. You must start the restore in NetWorker from the beginning.

For more information on these commands, refer to the online help, or the Mirapoint Administration Protocol Reference for your MOS version.

Reminders

• You can perform a selective restore on different MOS systems with the same release (e.g., restoring from 3.10 to 3.10, or restoring from 3.8 to 3.10). However, you cannot do a selective restore between MOS 3.x and MOS 4.x releases, nor can you perform a selective restore on systems with the same release restoring to an earlier release (e.g., restoring from 3.10 to 3.8).
• Full image restores are only possible to a Mirapoint appliance with an equal or larger size mail store that is on the same MOS release.