Getting Started with CA ARCserve D2D › Manage Backup Settings › Specify the Protection Settings › Estimate Future Backup Space Requirements

Estimate Future Backup Space Requirements

CA ARCserve D2D provides you with this handy tool to calculate the estimated amount of available free space that you will need for backups. The concept of this tool is based partially on your estimate of future data change and partially on the space occupied from previous backups.

To use this estimating tool

1. Select the backup source. This may be your entire machine or selected volumes within your machine.

   The actual size of the selected backup source will be displayed in the Total Source Size field.

2. Estimate the anticipated Change Rate for future backups.

   This estimate should be based upon past performance of how much your total backup size has changed for each subsequent incremental backup.

3. Estimate the Space Saved After Compression percentage value

   This estimate should be based upon past performance of your backups with different Compression settings applied.

   As you change this value, you will see the corresponding size impact for your backup sizes.

   Note: If necessary, you can perform some Full Backups, each with a different Compression setting (No Compression, Standard Compression, and Maximum Compression) to establish past performance values and help you to better calculate the percent of space saving that each setting will produce for your backup.

   • The Compressed Full Backup Size field will display a calculated value based upon:
     • Size of the backup source
     • Specified compression percentage.
   • The Compressed Incremental Backup Size field will display a calculated value based upon:
     • Estimated Change Rate
     • Number of recovery points to be saved
     • Specified compression percentage
   • The Estimated Total Backup Size field will display the anticipated space you will need for future backups and is based upon:
     • Amount of space required for one Full Backup plus
     • Amount of space required for the number of Incremental Backups needed to satisfy the specified number of saved recovery points.
4. From this Estimated Total Backup Size value, you should be able to determine if your backup destination has sufficient space to fit your backup.

   If you destination does not have sufficient free space, you may consider the following corrective actions:

   • Reduce the number of saved recovery points
   • Increase the available free space at the backup destination
   • Change the backup destination to a larger capacity
   • Reduce the size of the backup source (maybe eliminate unnecessary volumes from the backup)
   • Increase the Compression setting of the backup