DPM protects data on tape through a combination of full and incremental backups from either the protected data source (for short-term protection on tape or for long-term protection on tape when DPM does not protect the data on disk) or from the DPM replica (for long-term protection on tape when short-term protection is on disk).
The choices for retention range, frequency of backups, and recovery options are different for short-term and long-term protection.
|You can select disk or tape for short-term protection, but not both.|
Short-Term Protection on Tape
For short-term data protection on tape, you can select a retention range of 1–12 weeks. DPM provides management support of your tapes through alerts and reports, and it uses the specified retention range to establish the expiration date for each tape.
Your options for backup frequency are daily, weekly, or biweekly, depending on the retention range.
If you select short-term protection on tape using both incremental and full backups, the retention range will be longer than the one you specified (up to a maximum of 1 week longer) because of a dependency between full and incremental backups. Tapes containing full backup are recycled only after all dependent incremental tapes are recycled. Because full backup happen once a week and the incrementals daily, the weekly full backup tape must wait for the six daily incremental backup tapes to be recycled before the full backup tape is recycled. If an incremental backup fails and there is no incremental tape to recycle, the full backup tape will be recycled earlier.
Long-Term Protection on Tape
For long-term data protection, also known as tape archive, you can select a retention range between 1 week and 99 years. DPM provides management support of your tape archives through alerts and reports, and it uses the specified retention range to establish the expiration date for each tape.
The frequency of backup is based on the specified retention range, as shown in the following list:
- When the retention range is 1–99 years, you
can select backups to occur daily, weekly, biweekly, monthly,
quarterly, half-yearly, or yearly.
- When the retention range is 1–11 months, you
can select backups to occur daily, weekly, biweekly, or
- When the retention range is 1–4 weeks, you
can select backups to occur daily or weekly.