Page 42
DTL-960e Single Channel Colour Digital Video Recorder
User Manual
VOLUME INFORMATION
The Wavelet data headers that are stored at the beginning of a tape are stored in special files on the hard disk. This
volume information is stored on the hard disk to enable the contents on a tape to be recovered quickly in case the tape
drive was powered down while recording.
The volume information on the disk is also used to reference other tapes in the magazine. This speeds up the magazine
loading process, as only one tape has to be read to know the contents of the other tapes in the magazine. For this reason,
it is not advisable to change the order of the tapes in a magazine.
The software currently supports 32 volume partitions on the hard disk. When all available partitions on the hard disk have
been allocated, the oldest partition will be cleared and reused. Each time a tape is loaded, the time stamp in the
corresponding partition is updated. When factory settings are selected, all volume partitions are erased.
RESTORING TAPE HEADERS
If the SCSI link between the Digital Recorder and the tape drive fails while data is being written to the tape, as much
data as possible is restored when the link is re-established. Most of the header information is recovered from the
disk, with the remaining data recovered from the tape. This recovery operation typically takes several minutes,
depending on the relative position of the data from the start of the tape.
If the power to the drive is interrupted while the drive was writing data to tape, the data recovery process may take
considerably longer because the position of the last valid data must be determined.
WRITE-PROTECTION
The magazine can be write protected by moving the write protect tab to the Save position. In addition, individual tapes can
be write protected by opening the write protect tab on the tape.
If a write protected tape is chosen for selective archiving, no data will be written to the tape.
If a write protected tape is loaded during background archiving, the tape is returned to the carousel, and the next tape
in sequence will be loaded.
BLANK TAPES
If any blank tape is detected during the loading process, the tape will automatically be partitioned into two partitions, and
a blank set of headers will be written to the tape, so they are ready to receive recordings.
TAPE CAPACITY
The tape capacity is read from the drive when a new tape is being loaded. The capacity reported by the drive is only an
estimate, and varies with the make of the drive and tape. This estimated value is used in computing the percentage of
space left while background archiving (or when selecting events are to be archived).
ERASE MEDIUM
If more than one volume is detected, the user can use the
Erase Archive Medium
menu item to select one or more
volumes to erase. All selections will be off by default. More than one volume can be selected per erase operation.
If the selected volume is in the tape drive, the header partition on the loaded tape is erased.
If the selected volume is not in the drive, the selected tape is loaded and the headers are read. The tape is erased only
if the headers read from the tape match those on the disk for that position in the magazine.
If the headers on the tape are different from those on the disk, the tape positions in the magazine must have been
changed. In which case, the tape is not erased. The tape in position one must be removed, a new reading of the
magazine begins, and tapes will be erased.
The progress bar tracks the erase operation. It reaches 100% when all selected tapes have been erased. The bar is not
updated smoothly, but rather in stages during the erase operation. The progress bar does not change while a tape is
being selected (up to 3 minutes). The tapes are erased in sequence starting with the lowest selected ID, regardless of
which tape was originally in the drive.
Note:
When background archiving is active, certain tape functions are not available, such as
Erase Archive Medium
. In
order to erase a tape, turn background archiving mode off. See page 26 for details on how to do this.
All manuals and user guides at all-guides.com
