Volume Explorer

Overview

Volume Explorer maintains a database of the disk volumes attached to each MediaAgent and Image Level on Unix iDataAgents, and the Quick Recovery Agent client, including unique identifying information (WWN/LUN) for each volume. Also, two types of NetApp data server volumes will be displayed in Volume Explorer. Volumes on the primary data server will be displayed under the QR agent, if they are mounted on that client; the volumes on the secondary data server will be displayed under the data server name. Note that the NetApp NAS iDataAgent must be installed in order to detect the volumes.

This information can be used to determine when a single physical volume is mapped to different drive letters or paths on multiple hosts. The system can also look up this information during backup and restore operations, eliminating the need for tedious manual entry of WWNs and LUNs for each subclient or restore job.

For Windows clients, only hosts with the QR Agent and MediaAgent installed will appear in Volume Explorer.

For Unix clients, only hosts with the QR Agent and Image Level on Unix iDataAgents and the CXBF driver installed will appear in Volume Explorer. For AIX, Solaris and Linux, Volume Explorer will only detect volumes on disks that have been partitioned, or have had a partition table created on them. Data servers with secondary SnapVault licenses will be displayed for use with SnapVault.

See also DisableWWNDetect, a registry key that allows you to change the default WWN detection behavior of the Quick Recovery Agent.

Accessing Volume Explorer

To access Volume Explorer:

From the Tools menu in the CommCell Console, select Control Panel; or (if applicable), go to the Subclient Properties (Content) tab for your agent.
Click or double-click Volume Explorer and then click Yes at the warning prompt.

When to Use Volume Explorer

Run a Volume Explorer Detect operation for any of the following conditions:

after installing a new Image Level iDataAgent on Unix or QR Agent, but prior to configuring subclients. Valid Volume Explorer volume information is required prior to proceeding with subclient configuration.
after disk volumes on a Image Level on Unix, or the Quick Recovery Agent client, or a MediaAgent are added, removed, or reconfigured in any way (including partitioning and drive letter assignments). Note a special case for Linux clients: partitions that have been deleted on a locally connected IDE drive will continue to appear in Volume Explorer until the Linux client has been rebooted.
when configuring NetApp volumes for use with SnapVault.
for Image Level on Unix, and Quick Recovery Agent on Unix, to configure/deconfigure and mount/unmount CXBF devices.

Volume Explorer Display

The Volume Explorer interface consists of two panes. The left pane displays a list of eligible hosts (including all Windows MediaAgents and all clients with Quick Recovery Agent, or Image Level on Unix installed). The right pane lists the disk volumes that Volume Explorer has detected on the currently selected host.

At the top of the window is a toolbar with several available functions; to read more about each of them, refer to the Volume Explorer Help file.

The Detect operation scans for disk volumes currently attached to the selected host and compares their characteristics with the information in the Volume Explorer database. Volume Explorer will automatically add new volumes to the database. If previously configured volumes are not found during the scan, Volume Explorer will ask for permission before removing their records from the database. If the characteristics of a discovered volume do not match those in the database, Volume Explorer will ask you whether to preserve or update the database records.

Some types of disk hardware do not support the method of WWN discovery implemented by Volume Explorer. In such cases, Volume Explorer may report a Unique ID Type of ATAPI/IDE instead of Fibre Channel WWN. If you want to use a hardware device for SAN-based data movement, you will need to set the appropriate ID type and enter the WWN and LUN for each volume manually. On subsequent detections of the same volume, you should direct Volume Explorer not to update the database, or you will have to repeat this step.

Volume Explorer Volume Properties

Volume Explorer displays the following properties for each volume:

Device Name	the Windows device name, or Unix mount path for the volume.
Hostname	the hostname of the attached computer.
Scratch Pool	the Scratch Volume Pool to which this disk belongs, if any.
Assign button	allows you to assign the volume to a new or different Scratch Pool.
ID Type	the type of Unique Identifier to be used with this volume. If the disk is SAN-attached, the Fibre Channel WWN type should be used. If it is an internal disk, ATAPI/IDE is appropriate. If it is a virtual disk device created by QSnap, the QSnap ID type will appear here.
ID	a string (based on ID Type) that uniquely identifies the physical disk containing this volume. Note that multiple partitions on the same disk will have the same ID value, but different LB Offset values (see below).
LUN	A Logical Unit Number for the physical disk. This is used in conjunction with the FC WWN ID type to uniquely identify the logical unit on multi-LUN disk devices (e.g. RAID controllers).

Together, the ID Type/ID/LUN represent the unique identity of the physical volume. Some fields (e.g., WWN) are not always detectable by Volume Explorer. Therefore, Volume Explorer allows you to enter the correct values manually, if needed.

LB Offset	the Logical Block Offset at the beginning of the disk partition.
Block Count	the size of the partition in physical disk blocks.
Block Size	the size of a physical disk block in bytes.

If a Quick Recovery Agent volume creation/recovery operation fails, verify that the ID Type, ID, and LUN entries in Volume Explorer are correct.

Special Notes on Volume Explorer

Snapshots can be deleted in Volume Explorer. Use caution when deleting snapshots in Volume Explorer. Volume Explorer allows you to delete snapshots from the CommServe database, even if they are being used, or scheduled to be used by a job, causing the job to fail.
Volume Explorer will display all disk volumes found on the selected host, including those which are not connected to a SAN. Usually these non-SAN volumes will show up as ATAPI/IDE ID devices and LUN as zero.
Some SAN attached disk devices (e.g. EMC Symmetrix) do not support the WWN discovery method used by Volume Explorer. For these disks, you will need to enter the ID Type, ID, and LUN information manually. You will only need to do this once per volume.
In the case of a SCSI disk device that is connected to the SAN using a FC-SCSI router or gateway, Volume Explorer may be unable to detect the WWN correctly. Enter the WWN of the gateway, and be sure to use the LUN that is assigned by the gateway.
In the unusual case where a native FC device is connected to the SAN via a FC-SCSI router or gateway device, be sure to use the WWN and LUN assigned by the gateway device. The Volume Explorer may detect the WWN of the device itself rather than the gateway, so check these entries carefully to make sure that you provide the WWN and LUN assigned by the gateway. (This caveat does not apply to ordinary FC-AL hubs or fabric switches.)
For Unix volumes, Volume Explorer will only detect volumes on disks that have been partitioned, or have had a partition table created on them.