Why use the HP StorageWorks DLT 4115w Library?

•The HP StorageWorks DLT 4115w Library has a single DLT4000 drive with 15 slots. It has a total compressed storage capacity of 600 GB and a maximum sustained data transfer rate of 3 MB/s, or 10.5 GB/h, with data compression. This is the transfer rate assumed for the remainder of this section. Currently, the total amount of data to be backed up at ABC Pretoria to the HP StorageWorks DLT 4115w Library as a full backup, whether this is a single full backup, or the staggering approach is used, is about 22 GB. Assuming that the size of an incremental backup is approximately 5% of that of a full backup, a backup generation, representing a full backup and all incremental backups based on this full backup, requires (22+22*5%*5) GB, or 27.5 GB, of library space. In five years time, this figure is projected to increase to about 68.75 GB. ABC’s backup policy requires that three backup generations of data be kept. Therefore, 68.75*3 GB, or 206.25 GB, of library space will be required for storage. The HP StorageWorks DLT 4115w Library’s 600 GB storage capacity therefore suffices.

HP StorageWorks DAT24 autoloaders are used to back up the Microsoft Exchange Server and Microsoft SQL Server at ABC Cape Town as well as each of the 7 Cell Managers in the 3 MoM environments.

Why use the HP StorageWorks DAT24 Autoloader?

•The HP StorageWorks DAT24 autoloader has 6 24-GB data cartridges. It has a total compressed storage capacity of 144 GB and a maximum sustained data transfer rate of 2 MB/s, or 7 GB/h, with data compression. This is the transfer rate assumed for the remainder of this section. Currently, the total amount of data to be backed up to the HP StorageWorks DAT24 autoloader connected to the aforementioned Microsoft Exchange Server at ABC Cape Town is 15 GB. Assuming that the size of an incremental backup is approximately 5% of that of a full backup, a backup generation, representing a full backup and all incremental backups based on this full backup, requires (15+15*5%*5) GB, or 18.75 GB, of space. In five years time, this figure is projected to increase to about 47 GB. ABC’s backup policy requires that two backup generations of data be kept. Therefore, 47*2 GB, or 94 GB, of library space will be required for storage. The HP StorageWorks DAT24 autoloader’s 144 GB storage capacity therefore suffices.

How long does a full backup last?

The SAP database servers in the three cells at ABC Cape Town contain about 74 GB of data to be backed up to an HP StorageWorks DLT 4228w Library. This

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Backup scenarios