SyncDat Options

The following configuration options can be used to control and customize the behavior of syncdat.  Most options can be specified on either the command line, or in a configuration file.  Command line settings will override configuration file settings.

Options with the "Boolean" type take no parameter on the command line, but require a value of 0 or 1 in the configuration file.

Run Modes

Each of the following options causes syncdat to perform the given synchronization or maintenance task.  If you do not specify a mode, "Peer Mode" will be used.

CLI                 Value
-A user[:passwd]@host:
  Add a set of authentication credentials to encrypted storage.  You must specify a port number using -p if the server is not on port 8080.
-E user@host:
  Expire and remove a set of authentication credentials from storage.  You must specify a port number using -p if the server is not on port 8080.
-l LocalMaster Boolean
  The remote directory will be changed to make it identical to the local directory.  See the "Local Master" section.
-r RemoteMaster Boolean
  The local directory will be changed to make it identical to the remote directory.  See the "Remote Master" section.
-R Register an MTP/IP license code then exit.  You may provide the license code on the command line or enter it when prompted.

General Settings

These options set the general run-time behavior of syncdat.

CLI Config          Value
-C NoPWCache Boolean
  Do not load or save the password cache.  If a password is required, you must provide it on the command line or in response to a prompt.
-d Debug 0 to 6
  Enable diagnostic output.  Level 1 is recommended any time you are experiencing difficulties.  Levels above 1 will produce copious output and may degrade performance.
-D NoDelete Boolean
  All delete actions will be ignored.  Files removed from one side of a synchronization will be allowed to remain on the other side.
-f path name
  Read the given configuration file instead of searching the default paths.  syncdat will ignore all configuration files if you specify: –f ""
-K Encrypt Boolean
  Require all content to be encrypted.  If the server does not support content encryption, an error will be returned.  Usernames and passwords are always encrypted, regardless of other settings.
-n NoAction Boolean
  Scan the directories and report what actions would be taken, but do not actually make any changes.
-p Port UDP Port
  Specify the UDP port of the server.  Use this option if the server is running on a port other than the default 8080.
-q Quiet Boolean
  Display minimal output.  Automatically enables -y
-t TryInterval fail | skip | seconds
  Set the behavior of the Automatic Retry option.
-v Verbose Boolean
  Display each individual action.  If used without other options, display the syncdat version then exit.
-W Windows domain
  Specify a Windows authentication domain.
-y Yes Boolean
  Disables interactive queries by assuming the default answer to all questions regarding conflicts and confirmations.

Performance

These options set performance parameters and resource utilization.  Server side settings will also influence performance.

CLI Config          Value
-a Aggression -3 to 5
  Advise MTP/IP as to how aggressive it should be in fully utilizing the network path.  Aggression affects relative performance compared to all other data flows sharing the same network path, similar to prioritization.  It is very rare to need to set aggression higher than 2.  Never set an aggression level of 4 or higher without careful testing.  See the Performance section for details.
-e Expire seconds
  Sets how long syncdat should wait without hearing from a server before it gives up and aborts a stalled transaction.  Longer values may be useful on highly unreliable networks.  Default: 40 seconds.
-k MaxRate kilobytes per second
  Set a limit on how fast each transaction can go in kilobytes per second.
-L Latency milliseconds
  Advise MTP/IP of operation on a path with very high latency.  The value should be the minimum observed round trip time of the path, in milliseconds.  This setting will have no effect for RTTs less than 500ms and has little effect for RTTs less than 2000ms.
MaxRTT milliseconds
  Request that the path latency for each transaction be limited to the given amount of time.  Use this option if other applications (such as VoIP or video) require that latency along the path be kept below a specific target.  Transfer speed will be reduced any time latency exceeds this value.  This could severely degrade performance if other network traffic is causing high latency.  Consider Aggression level -3 as an alternative.
MinRTT milliseconds
  Advise MTP/IP of operation on a path with very high latency.  The value should be the minimum observed round trip time of the path, in milliseconds.  This setting will have no effect for RTTs less than 500ms and has little effect for RTTs less than 2000ms.
-N NoiseRatio 4 to 5000
 

MTP/IP normally regards packet loss as an indication of network congestion.  This option will cause MTP/IP to ignore packet losses up to a rate of one in N, for a given number N.  For example, a value of 100 will cause MTP/IP to ignore a loss rate of up to 1%.  This option should only be used on noisy data paths where loss is occurring due to external factors such as uncorrected bit errors.  Improper use of this option may severely disrupt the network and result in a loss of performance or connectivity, especially when Aggression is elevated.

NoiseRatio is not compatible with servedat 1.11.4 or earlier and will cause the transaction to fail.
Site address[/bits] Aggression MaxRate Expire MaxRTT MinRTT
  Configure performance for an particular server.  Address must be a DNS name, IP address, or subnet.  For subnets, use an address followed by a slash and the number of mask bits.  The remaining fields are white space separated and correspond to the named configuration variables.  A value of 0 implies that the default should be used.  You may have multiple Site declarations.
-S StopTime Minutes
  Limit the total runtime of syncdat to this many minutes.  Any transactions in progress at this time will be aborted.
-T MaxDatagram bytes
  Limit the size of network datagram payloads to no more than this amount.  The full IP datagram size will be 56 bytes larger when MTP/UDP/IP headers are included.  Tunneling, VPNs, IPsec, MPLS and other encapsulations will add more.  If your network is known to have an MTU less than 1500 bytes or problems with IP fragmentation, try setting a value of 1408 or smaller.
-U MinDatagram bytes
  Use network datagram payloads of at least this size.  If your network path is very fast (gigabit or more) and every device along that path supports Jumbo frames (MTU 9000), you may be able to improve performance by setting this to 8192.  Even larger values, up to 61440 may be used on networks configured to support such MTUs (e.g. InfiniBand).  Settings above 1408 without Jumbo frames fully supported may cause severe performance problems or loss of connectivity.  Note that setting MinDatagram will increase the minimum throttling limit discussed in the Performance chapter.