Troubleshooting
Implementing nTier Deduplication
101
and tape drives. If the device appears in the backup software, but it is not attached
to the expected component, it may be related to the serialization. Refer to your
backup software manual for any patch or upgrade related to serialization on the
backup software.
Backup server sees the tape library/drive but cannot access it
Check device
access by OS
Check if the backup server’s operating system can access the device or if it is the
backup software that cannot access the tape library or drive.
Depending on the OS you can use a raw device utility. Most of these tools work with
tape drives; they are not capable of moving tapes into the drives. Even if some can
move tapes, you need to know the exact address of the tape and the drive.
We recommend that you use the Console to put a tape in a drive before running
these tools. Also, stop the backup software before you use these utilities:
•
Windows
- For IBM Ultrium devices you can use
ntutil
, a command line tool
that can check the tape device.
•
Unix systems
- You can use the
mt
or
tar
commands to access the tape
device, for example:
mt -f /dev/rmt/0 status
OS cannot
access device
If the operating system
cannot
access
the device, you need to troubleshoot virtual
device access.
•
Go to the storage to verify that it is not in error or in an abnormal state. The
assigned devices have to be in read/write mode.
•
Check the Event Log or syslog for message indicating IO errors. Such
messages usually begin with
log_scsi_error
.
•
Check backup server driver - Go to the backup server and check the
adapter driver version. It should be certified for use with FalconStor VTL.
OS can access
device
If the operating system
can access
the device, you need to troubleshoot the backup
software. Verify that you have the correct drivers.
Deduplication
Deduplication is configured to begin after a tape is virtually unloaded from a tape
drive and moved to a slot.
If the option to unload a tape when it isn’t needed isn’t available when you define a
job, you must run deduplication manually. To do this:
1. Expand the
Drives
object under the virtual tape library so you can see individual
tapes.
2. Identify the tape that needs to be deduplicated.
Right-click the tape and select
Move to slot
.
3. Select
Yes
in the resulting message box.
