Resolve a Read-Writable .bzvol Directory Error

When you select a drive for a backup, Backblaze Computer Backup creates a unique hidden folder called .bzvol at the root of each hard drive that you back up. Then a bzvol_id.xml file is created inside of that folder. If Computer Backup cannot create the folder, it displays the message: "Backblaze could not create a read-writable '.bzvol' directory on that hard drive."

Most commonly, this happens if there is an issue with the drive's formatting on a macOS computer. It can also happen if there is an issue with drive permissions on a Windows or macOS computer.

Resolve a Drive Formatting Issue (macOS)

If your operating system can read a drive but cannot write to it, Computer Backup is prevented from creating the necessary .bzvol folder. This issue commonly occurs with NTFS-formatted drives on a Mac computer.

1. Transfer all of the files from the drive that has the issue to a different drive.
2. Erase the drive that has the issue using Mac's built-in Disk Utility app.
3. Use the Erase option, and select Mac OS Extended (HFS+) as the drive's new format.
4. Select the drive for backup in Computer Backup settings.

Configure a Drive's Permissions (Windows)

1. Ensure that you can view hidden files in Windows.
2. Navigate to the top level of the drive in File Explorer.
3. If the .bzvol folder already exists there, delete it.
4. Locate the drive in File Explorer, right-click the drive, and select Properties > Security.
5. If SYSTEM is listed, set it to Full Control.
6. If SYSTEMis not listed, add a system.
   1. Click Edit.
   2. Click Add.
   3. Enter SYSTEM in the Object Names field.
   4. Click OK.
7. Select Allow for all SYSTEM columns.
8. Click OK to confirm.
9. Reboot your computer.
10. Select the drive for backup in Computer Backup settings.

Configure a Drive's Permissions (macOS)

1. Navigate to the drive in Finder.
2. Control-click the drive, and select Get Info.
3. In the Sharing & Permissions section, click the lock icon and enter your system credentials when prompted.
4. For the field that says system (or me), ensure that the Privilege column is set to Read & Write.
5. Select the drive for backup in Computer Backup settings.