360 Systems Instant Replay DR-554 - Manual (Page 39)

Instant Replay Owner's Manual Page 39
Backup/Restore Characteristics
BACKUP BANK saves a specific bank to a DAT tape. BACKUP DRIVE saves the contents of the
entire drive to a DAT tape. RESTORE FROM BACKUP adds files to the drive from the DAT backup
tape, replacing any with the same Cut Index. RESTORE FROM BACKUP does not discard files on
disk unless a file at the same Index is successfully read from the DAT tape.
Backup and restore data for AC-2 encoded Cuts is left in its compressed form, so a disk with 4 hours
of audio can be backed up using about 65 minutes of DAT tape. A disk with 8 hours of audio can be
backed up with about 115 minutes of tape.
Backup and Restore support the AES/EBU interface only.
Note: The device used to store the data must not alter the data in any way, such as through signal
processing (high-pass filtering or data compression, for example) or sample rate conversion.
Although this discussion assumes the use of a DAT recorder, any AES/EBU compliant device that
meets the above criteria can be used. Instant Replay data has been successfully saved on to digital
multitracks and 360 Systems DigiCart/II using the 48K Linear format.
We recommend that you keep at least two copies of important data on each of at least two different
tapes. In the event that one tape develops an error, simply repeat the process of restoring using one of
the copies. Unless the error occurs on the same file in both tapes, all the files will remain on the hard
drive.
CAUTION!
PLAYBACK OF BACKUP DATA OR D-NET TRANSFER SOUNDS LIKE LOUD NOISE AND BEARS
NO RESEMBLANCE TO THE UNCOMPRESSED MATERIAL. EQUIPMENT MONITORING THE
DIGITAL OUTPUT COULD BE DAMAGED IF LEVELS ARE EXCESSIVE.
Managing Large Drive Backup.
When using DAT tapes to back up data from 2 Gigabyte or larger drives that contain more than about
1 Gigabyte of material, the length of backup files can exceed the length of a single DAT tape. In this
case it is necessary to do individual Bank backups. If you have Cuts to back up that are not assigned
to Hot-Keys in any Bank, they must be assigned to a Bank for the purpose of backing them up. If you
have more than 50 unassigned Cuts, back up the first 50 then reprogram the Bank and repeat the
backup. It is suggested that you reserve Bank 10 for this function.
If it is not possible to reserve a Bank, then when backing up first back up the ten banks that exist, then
reprogram one or more of the banks with temporary assignments to the unassigned Cuts. When you
are finished, reload the banks that you reprogrammed from their backups or manually reassign the
Hot-Keys. When restoring, load the Banks of unassigned Cuts first, then load the Banks with the
Cuts that are to remain assigned.
Verifying tapes
When Instant Replay loads files from a backup tape it holds them in a temporary file until the entire
file loads and is checked for errors. Only then is the file allowed to replace any existing file in the
same Index number. This allows you to perform the Restore from Backup process to verify that a
backup tape is good. Any files that contained errors on the backup will not overwrite the good files on
the hard drive. Note that you must have sufficient hard drive space to hold the largest of your Cuts;
insufficient space will result in file creation errors during the verify process. This will not hurt the
data on the hard drive, but it will cause the backup tape to appear to be flawed.
Loading Multiple Tapes
You can load multiple backups with differing material as long as they do not contain conflicting
Index Numbers. In the case of a conflict only the last Cut with that Index number remains. You can
use the Move function before loading the second backup to resolve Index Number conflicts.