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    Article summary

    Snapshots are ZIP files that you can create from downloading files that are stored in a Backblaze B2 Cloud Storage bucket. A Snapshot is a convenient way to download many files for a single point in time.

    When you create a Snapshot, a Backblaze B2 proprietary bucket is created to store the Snapshots. The Backblaze B2 proprietary Snapshot bucket has the prefix b2-snapshot-. You can download Snapshots using the Backblaze web UI, the command-line tool, or third-party tools like Cyberduck or Transmit.

    If you want to disable Backblaze B2 or delete your account, you must remove all of the Snapshots that you created from the Snapshot bucket first.

    Size and Cost

    The maximum size for a single Snapshot is 10 TB and 10 million files. When you create a Snapshot using the Backblaze web console, you are not charged for any Backblaze B2 transactions that are involved in creating the Snapshot, nor any processing time on Backblaze servers. You are charged only for the Snapshot’s storage after you upload files to your Snapshot bucket.

    Estimated Processing Time

    Based on statistics, you can expect Snapshots to take approximately 1 minute/GB.

    This performance varies with Snapshots that include many small files (> 100,000) or large Snapshots with very few files.

    At 1 min/GB, very large Snapshots can take several days to run. You should also be aware that Backblaze has a regularly scheduled maintenance period each Thursday at 2pm PT. During this period, servers are offline for a brief maintenance. Snapshots that are in progress during this maintenance period stop and are restarted after the servers are back up. This can add several hours of additional time to the Snapshot’s normal processing, especially for larger Snapshots.

    Snapshot Candidate List

    If files are deleted from Backblaze B2 after you submit the Snapshot, while the Snapshot is running, it is noted in the Snapshot’s error log for up to 50 deleted files. It is up to you to determine whether the Snapshot is valid or should be recreated. Do not delete Backblaze B2 source files until the Snapshot is complete and you are certain that the Snapshot is viable.

    Hidden Files

    By default, Backblaze B2 hidden files (action=”hide”) are not included in the Snapshot. If all of the files that are in a bucket are “hidden,” then the Snapshots display an error in the status because there are zero (0) files to download. There is a checkbox on the Submit Snapshot screen that includes all hidden files in the Snapshot.

    Snapshot Size

    Larger Snapshots 2TB to 10TB tend to be difficult to work with and time-consuming to create. Split large Snapshots into smaller Snapshots to spread them out over Backblaze servers and for faster recovery if a Snapshot ZIP file has issues.

    Build Progress

    Snapshots run in the background on Backblaze servers. You can monitor the progress of a Snapshot on the Backblaze web console Snapshots page. The Backblaze servers progress through the following phases:

    • Downloading the candidate files
    • Zipping the files
    • Uploading the Snapshot to your Backblaze B2 Snapshot bucket

    If the Snapshot exceeds 100M, it is uploaded using the Native API large file process.

    The following statuses are reported on the Snapshots page:

      The candidate file is being submitted to the Backblaze restore servers.
      Files are being downloaded and put into a ZIP file.
      The ZIP file (<100M) is uploading to your Backblaze B2 Snapshot bucket.
      The ZIP file is uploading in parts to your Backblaze B2 Snapshot bucket.
    • ERROR
      An error occurred during processing, and the Snapshot has stopped running.

    Processing Errors

    Occasionally, Snapshots that you submit incur errors during processing for a variety of reasons. Backblaze staff monitor Snapshots while they are running. There may be issues that cause Snapshots to stop running and report an error. To the extent possible, Backblaze staff automatically restarts Snapshots and you do not need to take action. You should ensure that the Snapshot is viable after it is complete.

    Download Errors

    When you create a Snapshot and a candidate file is no longer available, the Snapshot does not fail, but it tracks the files that cannot be found. The list of files is displayed in an error list next to the Snapshot on the Snapshots page. Up to 50 entries are displayed, and it is up to you to determine whether the Snapshot is still useful or should be recreated based on the errors. Click the warning icon to view Snapshot details.

    Deleted Snapshot Buckets

    A Snapshot bucket appears on the Browse Files page even after you delete your Snapshot. This is not a visual error. After you create one Snapshot, you will continue to see a listing for a Snapshot with no contents in it. A Snapshot bucket exists forever even if you delete the Snapshots that it contains; the bucket never disappears from your bucket listings.

    The Backblaze B2 Snapshot bucket is a special "read-only" bucket that Backblaze uses for any Snapshots that you order. You are not able to delete it or directly write to it. It is used only for Snapshots. The bucket appears on the Browse Files page to provide another link to the Snapshot page and to show its usage. Future Snapshots that you create will use this same bucket.

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