The Data Protector Catalog Database is approximately 0.4 GB in size. It is backed up locally to an HP StorageWorks DAT24 autoloader, which has a sustained data transfer rate of 2 MB/s or 7 GB/h. Data Protector by default checks the integrity of the database before the database is backed up. It takes less than half an hour to check the integrity of a 0.4 GB database and only a few minutes to back up the database. Therefore, to check the integrity of, and then back up the IDB and configuration files requires less than 1 hour.

The projected size of the database in five years time is 1.2 GB. It takes less than an hour to check the integrity of a 1.2 GB database and less than half an hour to back it up. Therefore, to check the integrity of, and then back up the IDB and configuration files requires less than 2 hours.

All the other available data in the system, which is currently about 55 GB) is backed up remotely to the HP StorageWorks DLT 4115w Library, which has a sustained data transfer rate of 3 MB/s, or 10.5 GB/h. Most of this data is via the 100TX network, which has a sustained data transfer rate of 10 MB/s, or 36 GB/h, of data. This does not present a bottleneck. The backup of all these data would therefore take about 5 to 7 hours to complete. This is well within the allowed 12 hours. The problem would then be that in five years time, when the data is projected to be about 170 GB, the backup would take 15 to 21 hours!

To solve this problem, use the staggering approach. Schedule the full backup of data in the English Department for Fridays at 20:00, and that in the Other Languages Department for Saturdays at 20:00 and that in the Admin Department for Sundays at 20:00.

Table 17 The staggering approach

 

Mon

Tue

Wed

Thu

Fri

Sat

Sun

 

 

 

 

 

 

 

 

English

Incr1

Incr1

Incr1

Incr1

Full

Incr1

 

 

 

 

 

 

 

 

 

Other

Incr1

Incr1

Incr1

Incr1

Incr1

Full

 

Languages

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Admin

Incr1

Incr1

Incr1

Incr1

Incr1

 

Full

 

 

 

 

 

 

 

 

308

Backup scenarios