Archiving Job

The process of moving backup data from the performance or capacity tier to the archive tier is called an archiving job. This job occurs in a separate session and follows the default schedule of the offload job, which moves data from the performance tier to the capacity tier. During the archiving job, new backup data are offloaded to the archive tier, while the outdated backup data are cleaned up during the same archiving session.

How Archiving Job Works

The archiving job modifies the blocks of data from the performance/capacity tier and rearranges these data into blobs. The size of these blobs differs from the size of blocks of data on the performance/capacity tier and depends on the storage optimization option of a backup job.

When the archiving job starts, it analyzes the size of data blocks in the performance/capacity tier and rearranges these blocks of data into blobs according to the following rules:

• The blob must not contain more than 512 data blocks.
• The blob must not occupy more than 512 MB.

Depending on the storage optimization option, the size of a blob in the archive tier can be calculated the following way:

• If storage optimization option is set to 1 or 4 MB, the archiving job will rearrange data blocks into one single blob that occupies no more than 512 MB.
• If storage optimization option is set to 512 КB, the archiving job will rearrange data blocks into one single blob that occupies no more than 256 MB.
• If storage optimization option is set to 256 КB, the archiving job will rearrange data blocks into one single blob that occupies no more than 128 MB.

For example, due to the storage optimization option of a backup job, each data block located on the performance/capacity tier occupies no more than 1 MB. During the archiving job session, the job checks the blocks size and recompiles them into the larger blobs. Thus, the total amount of blocks in a blob will be 512, and this blob will occupy no more than 512 MB.

Considerations and Limitations

You can archive backups if they meet the following conditions:

• The type of backup file is appropriate. For details, see Archive Tier.
• [For the capacity tier] Backup files are offloaded to the capacity tier.
• Backup files belong to inactive backup chains.
• Backup files have been created N days ago according to Archive backup files older than N days setting of the Add Archive Tier step of the wizard.

• If you have selected the Archive backups only if the remaining retention time is above minimal storage period check box of the Add Archive Tier step of the wizard:

1. for Amazon S3 Glacier storage: only backup files with retention period no less than 90 days.
2. for Microsoft Azure Archive storage: only backup files with retention period no less than 180 days.

Backup files that meet all the following conditions will be cleaned up:

• Backup files that do not have original files on the performance tier.
• Backup files with expired or unspecified immutability period. For more information, see Immutability for Archive Tier.

After the archiving job is completed, the transported files are deleted from the performance or capacity tier. For capacity tier, it happens during the next offload to capacity tier session.

Cleanup Tasks

Cleanup tasks exist within archiving jobs. They are launched if there are only outdated backup files to delete during a certain job session, and no new backup files are to be offloaded to the archive tier.

Cleanup tasks do not require archiver appliances.