Estimate Media Capacity

Before you do a backup, be sure that your archive media has sufficient space.

When you estimate available space on disk or tape, keep in mind these rules:

Start a new tape for every backup.

Before starting a backup to disk, SAP Sybase IQ first tests whether there is enough disk file space for the backup. For an operator-attended backup to disk, if there is not enough space, BACKUP prompts you to move some files from the disk before it writes any data. The backup does not start until you provide more disk space.

Likewise, if you run out of space during an attended disk backup, BACKUP closes all open backup files and waits until it detects that you have cleared some space. Then it restarts with new backup files. You can also stop the backup if you prefer.

By default, you must provide at least 8KB of free disk space before the backup resumes.

Unattended backup cannot prompt you to provide more space. Unless enough space is available, unattended backup fails. BACKUP treats size estimates differently for unattended backups.

For an operator-attended backup to tape, BACKUP simply begins the backup. If it runs out of room, you must mount additional tapes.