Drive continually scanning media during backup (4043401)

Date – 07/2010
Affected Product & Version – NetVault: Backup 8.x
Affected Module & Version – n/a
OS Version – n/a
Application Information – n/a

Description:
After resubmitting a backup job that was previously aborted, a job can continue to run and enter a loop in which status reports “Running: Waiting for media” and the “drive contains media that must be scanned”.
This situation can happen on autoloaders that employ an ADI interface between drive and changer.

Symptoms:
Abort a backup job being written to a tape that contained previously successful backups and was blanked out for re-use. Then, start a subsequent backup job using this tape. An error pattern may be encountered when positioning the media to the logical End Of Data (EOD) in order to append data for the new backup job.
NetVault spaces a certain number of filemarks until it receives a Blank Check\EOD reached sense data from the drive. Once this condition is met, a loop could be entered in which the drive will continually report back being at EOD and the application restarting the scanning media process.

If the device gets into this state, the submitted job will output similar to the following:
Media SRV (LIBRARY)Job has been assigned media ‘MEDIA ID’ in ‘DRIVE’
Media SRV (LIBRARY)Media identified as ‘MEDIA ID’
Media SRV (LIBRARY)Device ‘DRIVE’ assigned to job,positioning media ‘MEDIA ID’ to segment 1
Media SRV (LIBRARY)Device ‘DRIVE’ contains media that must be scanned
Media SRV Scan ‘MEDIA ID’ from segment 1
Media SRV (LIBRARY)Starting to scan ‘MEDIA ID’ in DRIVE 1:SRV
Media SRV (LIBRARY)Finished scanning ‘MEDIA ID’ in DRIVE 1:SRV
Media SRV (LIBRARY)Job has been assigned media ‘MEDIA ID’ in ‘DRIVE’
Media SRV (LIBRARY)Media identified as ‘MEDIA ID’
Media SRV (LIBRARY)Device ‘DRIVE’ assigned to job,positioning media ‘MEDIA ID’ to segment 2
Media SRV (LIBRARY)Device ‘DRIVE’ contains

On the NetVault side, disable Send Overlapping Commands to the drive and changer.
* In the GUI, choose ‘Device Management’.
* Right mouse click on Library (assuming it is already configured.) in the Devices Panel. Select Modify option.
* In the Modify Library menu Library Selection Panel, Choose the Library by highlighting the library and then choose the Configure Tab.
* Highlight and right click on the library again and choose the Configure option.
* The Configure Device panel opens to the Configuration tab.
* This is a large panel with many options;
* Scroll down and near the bottom is a box that needs to be checked - "Do not overlap commands to arm and drive"
* Click OK when that is accomplished.
* You are then returned to the Modify Library Panel, Configure tab.
* Right Click the File Menu option at the top and select Save.
* A Information pop-up will indicate "Library Modified Successfully"

Additionally, disable Domain Validation on SCSI HBA BIOS.
For Adaptec HBAs, configure BIOS settings by entering the BIOS menus during POST (Power On Self Test).

The Adaptec Controller will display:
Adaptec SCSI BIOS v4.31.4
<< Press for SCSISelect(TM) Utility! >>

* Type in "Ctrl-A" key combination when prompted.
* Press "Enter" when adapter is displayed.
* Select “Configure/View SCSI Controller Settings” -> "Advanced Configurations”
* Set the Domain Validation option to "Disabled"
* Save, exit and reboot.

For HBAs other than Adaptec, contact the vendor for instructions on how to disable Domain Validataion.