Windows BMR: How BMR Works

Bacula Enterprise Only

This solution is only available for Bacula Enterprise. For subscription inquiries, please reach out to sales@baculasystems.com.

During backup, the WindowsBMR plugin analyzes host disks and partitions. It creates the directory C:/Bacula/winbmr and copies certain files and directories needed at restore time to that location (only a few MB). If a “Recovery” or a “System Reserved” partition is found, the plugin assigns an unused drive letter (usually the first free letter starting at T:) to it for the time of the backup. This drive letter is released at the end of the backup. If the system is EFI-enabled, the EFI partition is automatically mounted, its contents copied to C:/Bacula/winbmr/partitions/EFI, and the partition then unmounted.

The plugin adds all static volumes that have a drive letter assigned to the backed-up Fileset. As mentioned above you may exclude some drive letters using the “exclude” option, but be careful to not exclude an important drive or an unused letter (like T:) which the plugin might use for the “hidden” partitions.

Here are the directories and files you will find in the C:/Bacula/winbmr directory:

C:/Bacula/winbmr
C:/Bacula/winbmr/data
C:/Bacula/winbmr/data/bcd.bak
C:/Bacula/winbmr/data/bcd_active.txt
C:/Bacula/winbmr/data/bcd_all.txt
C:/Bacula/winbmr/data/disklayout.txt
C:/Bacula/winbmr/data/the_bacula_rescue_for_windows
C:/Bacula/winbmr/partitions
C:/Bacula/winbmr/partitions/EFI
...

Attention: The rescue process is case sensitive and expects to find the above files in this exact directory name: with an uppercase ’B’ and lowercase ’w’.

The BMR Rescue Access

The Director configuration entries presented next are required to run actual BMR Restore Jobs.

The client defined below will run from the Recovery Media during the WindowsBMR restore process and is a special client that is used for all WindowsBMR restores and thus should have a different name from any of the clients used for backup. The “0.0.0.0” address will be updated during the recovery process with the correct address of the host (client) on which you are restoring. We recommend that you use the name rescue-fd and to not use this particular client for any non-BMR operation. Under BWeb, go to the configuration part under Console and click on the Set BMR Console wizard to create all necessary resources called rescue-fd.

Client {
  Name = rescue-fd        # cliname, same as Console
  Password = "xxxpassxxx" # clipass
  FDPort = 9102           # cliport

  Address = 0.0.0.0      # dummy address
  Catalog = MyCatalog
  File Retention = 30 days
  Job Retention = 6 months
  Auto Prune = Yes
}

The named console defined below is used for BMR operations. It is important that it allows access to all needed Catalogs (Bacula Systems recommends using only one Catalog, unless there are some very specific requirements involved), Clients, Jobs and Locations. Limiting Access to Commands, Storage, Jobs, Pools and File Sets can be safer, but it depends on your configuration. We will show how to tune access control lists (ACLs) later in this manual. For a first try we recommend to set all ACLs to “*all*”.

Console {
  Name = rescue-fd          # cliname, same Client
  Password = "xxxpassxxx"   # conspass

  CommandACL = *all*
  ClientACL = *all*
  CatalogACL = *all*
  JobACL = *all*
  StorageACL = *all*
  ScheduleACL = *all*
  PoolACL = *all*
  FilesetACL = *all*
  WhereACL = *all*
  # The next two ACLs are required when using
  # Bacula Enterprise 8.8.0 and above
  UserIdACL = *all*
  DirectoryACL = *all*
  # This last ACL is available when using
  # Bacula Enterprise 8.8.0 and above but is not required
  RestoreClientACL = *all*
}

The client and console resources shown above must have the same name. Also as mentioned above it would be a bad idea to use the name of a production server as doing so makes it possible to accidentally do a BMR restore to a production server thereby destroying it.

Handling of Windows Volume Mount Points

Note that all paths containing a mount point must be named using ASCII characters exclusively, as otherwise at restore time the mount point will not be re-created. This limitation will be removed in a future WindowsBMR version.

If you cannot assign a drive letter to your Volume, you must explicitly add the path to your mount point directory to your Fileset resource. At restore time choose “Manual Partitioning”, create the Volume and mount the file system to its correct location before starting the restore. Do the same if the path of your mount point contains non-ASCII characters.