Job Results Directory Disk Space Calculation

You can use formulas to calculate the amount of space that is needed for the job results directory. The amount of space that is needed depends on the number of files to be backed up or restored and the average length of the file names and paths.

Some agents and components require additional disk space. To review these disk space requirements, see Agents and Components Requiring Additional Disk Space.

Before You Begin

Gather the following information:

• The number of files that are included in each type of job that you plan to run (backup, restore, snapshot, and deduplication)

• The average length of the path (including the file name) for all the files in each job type

• The number of restore jobs that you plan to keep for a longer period of time

• The value in the Limit the Max Cache size to box on the client Deduplication tab

  The default value is 4096 MB.

• The disk space values for any other components that are included in the jobs

Procedure

1. For each type of job that you plan to run (backup, restore, or snapshot), use the following formula to calculate the required disk space in bytes:

   job_type_multiplier x number_files_in_job x (average_characters_in_paths + average_trueup_factor)

   where:

   • job_type_multiplier is a value that you include depending on the type of job you are calculating (The value for backups is 6, restores is 1.5, and snapshot is 7)

   • number_files_in_job is the total number of files included in the job

   • average_characters_in_paths is the average number of characters in the full paths (including file names) of the files in the job

   • average_trueup_factor is the average factor for synchronization of data on the source disk and the index. The average_trueup_factor value is 72.

2. Use the following formula to calculate the required disk space for the job results directory:

   backup_disk_space + (restore_disk_space x number_long_term_restores) + (snap_disk_space x parallel_snap_jobs) + deduplication_cache_max + additional_disk_space

   where:

   • backup_disk_space is the disk space value that you calculated for backup jobs

   • restore_disk_space is the disk space value that you calculated for restore jobs

   • number_long_term_restores is the number of restores that you plan to keep for a longer period of time

   • snap_disk_space is the disk space value that you calculated for snapshot jobs

   • parallel_snap_jobs is the number of snapshot jobs that you plan to run at the same time (in parallel)

   • deduplication_cache_max is the value (in MB) in the Limit the Max Cache size to box on the client Deduplication tab

   • additional_disk_space are the disk space values of any other components, such as optimized scan cache, that are included in the job

     For hardlink files, use the following formula to calculate the additional disk space required for the job results directory: number_hardlink_files_in_job x (average_characters_in_paths + 130 Bytes)

     For GPFS, use the following formula to calculate the additional disk space required for the job results directory: 3 x number_files_in_job x (average_characters_in_paths + 60 Bytes)

     Note

     • For the network share jobs that create the .7z files, remember to keep additional disk space.

     • For the job types that you do not plan to run, ignore the calculations (or use 0).

Examples

Consider an environment with the following conditions:

• Number of files: 25,000,000 (25 million)

• Average number of characters in the file paths: 15

• Average true-up factor for a file size of 100 MB: 72

• Deduplication maximum cache value: 4096 MB (4.096 GB)

• Number of restores that are kept for a longer period of time: 1

• Number of snapshot jobs that run in parallel: 1

Example 1: Backup and Restore Jobs

The calculation for the job results directory disk size for backup and restore jobs is as follows:

1. Calculate the disk space required for each type of job:

   • backup_disk_space: 6 x 25,000,000 x (15 + 72) = 13,050,000,000 Bytes (12.15 GB)

   • restore_disk_space: 1.5 x 25,000,000 x 15 = 562,500,000 Bytes (0.563 GB)

2. Calculate the disk space required for the job results directory:

   12.15 + (0.563 x 1) = 12.713 GB

Example 2: Backup and Restore Jobs with Deduplication

The calculation for the job results directory disk size for backup and restore jobs with deduplication is as follows:

1. Calculate the disk space required for each type of job:

   • backup_disk_space: 6 x 25,000,000 x (15 + 72) = 13,050,000,000 Bytes (12.15 GB)

   • restore_disk_space: 1.5 x 25,000,000 x 15 = 562,500,000 Bytes (0.563 GB)

2. Calculate the disk space required for the job results directory, including the deduplication max cache value (4.096 GB):

   12.15 + (0.563 x 1) + 4.096 = 16.809 GB

Example 3: Backup, Restore, and Snapshot Jobs

The calculation for the job results directory disk size for backup, restore, and snapshot jobs is as follows:

1. Calculate the disk space required for each type of job:

   • backup_disk_space: 6 x 25,000,000 x (15 + 72) = 13,050,000,000 Bytes (12.15 GB)

   • restore_disk_space: 1.5 x 25,000,000 x 15 = 562,500,000 Bytes (0.563 GB)

   • snap_disk_space: 7 x 25,000,000 x 15 = 2,625,000,000 Bytes (2.625 GB)

2. Calculate the disk space required for the job results directory:

   12.15 + (0.563 x 1) + (2.625 x 1) = 15.338 GB

Related Topics

For information about the Limit the Max Cache size to option, see Deduplication - Advanced Client Properties.