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Multi-Spanning
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Multi-spanning gets activated directly in Z-DBackup!
Z-DATdump was developed mainly as a module for Z-DBackup to allow backups configured in Z-DBackup to be copied onto tape. This is why some backup functionality is only available in Z-DBackup and not in the standalone version of Z-DATdump (e.g. multi-spanning and sending emails)
To use multi-spanning you have to setup a backup set and activate the option in Z-DBackup.
Multi-Spanning
The files will be spread across multiple tapes.
The amount of empty tapes needed will be determined at the beginning of the backup process. Z-DATdump presumes that 96% (default value) of the native tape capacity can be used to store the data (this value (used tape capacity) can be changed in the settings of Z-DATdump).
The native tape capacity is the capacity of the tape without taking hardware compression into account. The remaining capacity (4% by default) is used for file information and tape markers by Z-DATdump and also serves as a buffer in case there are 'bad blocks' on tape (blocks that can't be used for data storage anymore). The number of bad blocks on a tape increases over time, depending on how ofter the tape gets used. A bad block can only be determinded when you try to write data on tape. That's why Z-DATdump can't determine beforehand how many bad block the tape has and thus how much data actually fits on the tape. The default value of 96% of actually available space for data on the tape is only an estimate. If it turnes out that not all files that should be written to tape can be stored on it due to too many bad blocks, the backup will fail. In case this happens you should reduce the used tape capacity in the settings of Z-DATdump.
.png) Tapes of the same native tape capacity have to be used for multi-spanning. A maximum of 20 tapes can be used.
 Single files cannot be split up. The largest file may not be larger than the capacity of one individual tape.
Multi-Spanning is not possible when the tape backup is started by a schedule or when Z-DBackup/Z-DATdump are run as a service, because the tape exchange must be done manually.
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