NMDS_HA

 

  • Nomad PBA Task Sequence steps are not designed for use with offline USMT or WinPE

  • -NMDS_POLL command-line option for the NomadPackageLocator.exe tool cannot be used in WinPE

  • -NMDS_<command> command-line options for NomadBranch.exe have not been tested in WinPE, so their behavior may be unpredictable in that environment.

The NMDS_HA argument is available on the NomadPackageLocator.exe (recommended) or NomadBranch.exe service argument-line. It creates additional backup copies of the user data that has been copied to the PBA share, so it must be run after the share has been closed using NMDS_COMPLETE. It is only for use within a task sequence.

If configuring PBA command lines manually and using NomadPackageLocator.exe (NOT NomadBranch.exe) to run within a task sequence environment, if the task sequence variable 1EDisablePBA_HA = True, then High Availability is disabled. This variable is automatically set for Remote WSA deployments. If using NomadBranch.exe in the command line, the variable is ignored.

NMDS_HA takes the following format:

Copy 
NomadPackageLocator.exe -NMDS_HA,<min_backups>,<max_backups>,<synchronous_backups>

or

Copy 
 NomadBranch.exe -NMDS_HA,<name>,<store_host>,<min_backups>,<max_backups>,<synchronous_backups>

Using the following parameters:

Parameter

Description

<name>

Used to identify the shared cache and must be the same as the one used in the NMDS_POLL argument that initially requested the share. The version NomadPackageLocator.exe gets this from task sequence environment variable %PBAComputerName%.

<store_host>

The name of the host where the primary copy of the user data is stored. The version NomadPackageLocator.exe derives this from task sequence environment variable %OSDStateStorePath%.

<min_backups>

The minimum number of hosts to attempt to back up the user data to. Nomad will verify that this number of hosts respond to the request, although actual copying of the user data to them all may fail. This must be at least 1 and cannot be more than the maximum number of backups. If fewer than this number of backups is successful, the task sequence step fails.

<max_backups>

The maximum number of backups to attempt. The upper limit is 6.

<synchronous_backups>

The number of synchronous backups, i.e. the number of backups for which to wait before moving on to the next action in the task sequence, to ensure that at least this quantity of backups has been successful. If any backups remain they will be run in the background in parallel with the rest of the task sequence. The value can be less than the minimum number of backups but not more than the maximum. 0 is allowed but is not advisable as there is no guarantee that any backup is successful.

The output from the NomadBranch.exe version, if successful, is a comma-separated list of the host names of the extra data stores. With NomadPackageLocator.exe the task sequence environment variable %PBAHAHosts% is set to contain the list of host names.

Task Sequence environment variables

NMDS_HA uses the following task sequence environment variables:

Name

Use

%PBAComputerName%

Used as the cache ID

%OSDStateStorePath%

The full path of the share where the user data is stored. The hostname part is used to get the name of the host where the primary copy of the user data has been stored.

%PBAHAHosts%

Set to a comma-separated list of the names of the hosts with the backup copies.