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Summary

This article provides a procedure to iSCSi mount previous backups to a Windows host, after restoring an NDMP SMTape volume backup.

 

Resolution

Most of the procedure for accomplishing the above task is provided in How to Protect SnapVault Data on Tertiary Storage and Recover the Data. These knowledge base articles, however, are specific to recovering data from NDMP "dump" backups. While the procedure below lists points specific to accessing Open System SnapVault (OSSV) backups through iSCSI mounting after a full volume SMTape restore. Consult the knowledge base articles above for additional details on this procedure.

Important: Perform this procedure from a terminal session to your storage system.

The following suggestions will make this procedure easier to use:

  • Enter the command-line statements required into Microsoft Windows NotePad. Enter the long path names in this procedure into NotePad and cut/paste them into the terminal session. If you make a typing error in a command, correct the command in NotePad and then cut/paste the corrected command into the terminal session.
  • Download the free terminal emulator PuTTY, which has features such as cut/paste and window resizing. While you can use Windows cmd and Windows telnet, they can be cumbersome, so we suggest PuTTY.
  • Have ready the qtree name associated with the drive that you want to iSCSI map. If you have a base backup job log for this host, check the log and match the order of task start with the new qtree creation name. If you use Backup > NDMP to drill down into the volume, .snapshot directory, and then a snapshot, you see the actual qtrees created for the job. If the qtree looks like:

    ServerName@A15724CA182711DC8DAA000C292C2C84

    Then, select Backup > Raw, browse the host and use the volume information to map drives to qtrees.

    If your qtrees look like:

    [ServerName]JobName@{888B6DE3}

    Then you must find this information through other methods. In Windows 2003, you can find this volume string using the vol command. An example from a C drive follows:

    C:\> vol c:
    Volume in drive C has no label.
    Volume Serial Number is 888B-6DE3

    Otherwise, use the procedure in How to Protect SnapVault Data on Tertiary Storage and Recover the Data to obtain this data from the storage system. You may also be able to save time by using CIFS/NFS sharing of the volume to obtain the same information referenced in How to Protect SnapVault Data on Tertiary Storage and Recover the Data.
  • Keep the Data ONTAP FilerView web software interface open. Cut/paste portions from web pages to use in constructing necessary command lines.

To iSCSI map snapshots after an NDMB restore:

    1. Restore the SMTape backup to a storage system.

      Important: SMTape backup and restore only operate on the full volume level. Because you are restoring the whole volume in this procedure, you do not need to create another snapshot, since the restored volume contains all of the snapshots available at the time of the backup.
    2. When the data is restored, the volume is in the snapmirror state, which is read-only. The volume needs to be broken off from the snapmirror state before an iSCSI LUN can be created. For example, if you restored to a volume called /vol/restoreVol, then use:

      snapmirror breakrestoreVol
    3. Determine the path to the beximage.raw file that you want to convert to a LUN:

      a. Use Data ONTAP FilerView to browse snapshots filtered by the restored volume
      name. You can see the actual date the snapshot was taken. BEX/NSB
      snapshot names are typically in the form SSSV_JobName.0, where <JobName> refers
      to the backup job name. The trailing 0 is the number of the backup.

      b. When you know the snapshot, use the BEX/NSB management console to find the
      entire path you need. Select Backup > NDMP, drill down into the restored volume,
      then into the .snapshot directory, and open the snapshot you want. Example path
      names follow:

      /vol/restoreVol/.snapshot/SSSV_JobName.0/[ServerName]JobName@
      {888B6DE3}/BEXIMAGE.RAW
      /vol/restoreVol/.snapshot/SSSV_JobName.0/ServerName
      @A15724CA182711DC8DAA000C292C2C84/BEXIMAGE.RAW
    4. When you know the entire path to the beximage.raw file you want to iSCSI map, create the LUN from the Data ONTAP command line. The LUN name must be unique. If you are creating several LUNs, assign simple, recognizable names. An example of creating a LUN follows:

      lun create -b /vol/restoreVol/.snapshot/SSSV_JobName.0/[ServerName]JobName@{888B6DE3}/BEXIMAGE.RAW -o noreserve/vol/restoreVol/LUN-file

      Note: If the following error displays, "lun create: Read-only file system," review Step 2 above. The volume must be in a read/write state. If the following error displays, "lun create: No such LUN exists in snapshot," then the path name entered has a typographical error. Re-check your typing and try again until successful.

      When the LUN is successfully created, view the new LUN with either the lun show command or select LUNs > Manage in Data ONTAP FilerView.
    5. Associate your iSCSI target computer to an igroup. Refer to How to Protect SnapVault Data on Tertiary Storage and Recover the Data for specific details. Obtain the initiator name from the Windows iSCSI initiator utility from the host where you want to mount this LUN. Use this name to create an igroup. Use the igroup to map your new LUN to its intended host. An example of creating an igroup follows:

      igroup create -i -t windows RESTORE_GROUP iqn.1991-05.com.microsoft:bex301ms.servername.mydomain.com
    6. Map the LUN created to the igroup with:

      LUN map/vol/restoreVol/LUN-file RESTORE_GROUP
    7. When the LUN is mapped, do one of the following: If this computer has not used iSCSI initiator before, following the procedure in How to Protect SnapVault Data on Tertiary Storage and Recover the Data. Or, if iSCSI was installed and used previously, continue with step 8.
    8. If iSCSI was installed and used previously on the computer, you may need to use the iSCSI initiator utility to log out of and back into the storage system. Refer to the image below:


To log out and back into the storage system:
a. Click the Targets tab.

b. Select the storage system's target name and select Details. The Target Properties
dialog box displays.

c. Select the check box next to the identifiers, select Log off and click OK. The Target
Properties dialog box displays.

d. Select the target name In the Targets tab and select Log On. Windows re-scans
available SCSI devices and populates the Targets tab.


Note: If the drive does not display, select Computer Management > Disk Management. This often forces Windows to probe available drives and make iSCSI drives visible.

9. When you are finished using this iSCSI mount, do the following:

a. Select LUNs > Manage in Data ONTAP FilerView and delete the
LUNs you created.

b. Reboot the Windows iSCSI host to clear all traces of the mounted drive.