Table of contents
Troubleshooting
Introduction
This page lists the most common errors encountered in SyncPlanet as well as their fixes. If you've encountered an issue that is not listed here, please contact us
In addition, some of our subscription plans include full support days.
Identifying Errors
Whenever a storage unit encountered an error, a icon will appear next to it. A message explaining the error as well as possible fixes will be shown on the icon tooltip. You can also click on the storage unit name to display the message in its page.


Further Information
To learn more about an error, find its error or exit status code. It can be found in the storage unit's JSON, under the error key in its JSON. The example below shows code 255 (ssh connection error):
{
"_id": "vol_01FWEWD03P2A13ZWQS3VAWEXAE",
"shortName": "Studio5 Motion",
"bytesRemaining": 928866540,
"bytesTotal": 955756540,
"bytesUsed": 26890000,
"enable": true,
"error": 255
}
Tip
A 0 exit status code means that the process succeeded without error
Error Codes
There are two types of error codes, rsync and ssh.
rsync error codes
From the rsync manual page:
- 0 Success
- 1 Syntax or usage error
- 2 Protocol incompatibility
- 3 Errors selecting input/output files, dirs
- 4 Requested action not supported: an attempt was made to manipulate 64-bit files on a platform that cannot support them; or an option was specified that is supported by the client and not by the server
- 5 Error starting client-server protocol
- 6 Daemon unable to append to log-file
- 10 Error in socket I/O
- 11 Error in file I/O
- 12 Error in rsync protocol data stream
- 13 Errors with program diagnostics
- 14 Error in IPC code
- 20 Received SIGUSR1 or SIGINT
- 21 Some error returned by waitpid()
- 22 Error allocating core memory buffers
- 23 Partial transfer due to error
- 24 Partial transfer due to vanished source files
- 25 The --max-delete limit stopped deletions
- 30 Timeout in data send/receive
- 35 Timeout waiting for daemon connection
ssh and other error codes
Ssh will show a 255 or 127 exit status if an error occured. Otherwise, it will show the exit status of the remote command.
Diagnostics & Solutions
Below you will find a list of errors by numerical order as well as their possible fixes:
0 | Success
The storage unit is working as intended.
1 | Syntax or usage error
Please check the syntax of the options you are currently using and if these options are valid rsync options.
2 | Protocol incompatibility
No description currently available
3 | Errors selecting input/output files, dirs
Please check that you have entered the correct paths for your files.
4 | Requested action not supported: an attempt was made to manipulate 64-bit files on a platform that cannot support them; or an option was specified that is supported by the client and not by the server.
No description currently available
5 | Error starting client-server protocol
No description currently available
6 | Daemon unable to append to log-file
No description currently available
10 | Error in socket I/O
No description currently available
11 | Error in file I/O
No description currently available
12 | Error in rsync protocol data stream
The remote storage runs an older rsync command and has a protocol version lower than expected. Please upgrade rsync on the remote storage unit's host machine.
Tip
It is a good idea to check which version of rsync produceed this error, and update it to the latest version if it is not up-to-date. Removing the rsync option --compress for this link should resolve the issue. It happens if the remote host is a Synology with limited hardware. Removing the option also allows for high transfer rates (x4).
Important
Error 12 can also occur if rsync is ran using the rsync --rsync-path option and if the specified path is not found.
Important
Error 12 can also occur along with this type of message:
deflate on token returned 0 (470 bytes left)
rsync error: error in rsync protocol data stream (code 12) at token.c(476) [sender=3.2.3]
This error might happen on big compressed files, like .mov of .mp4.
14 | Error in IPC code
This is likely an error in the rsync command syntax. Please check the rsync options in your configuration to find a mistake in the syntax.
20 | Received SIGUSR1 or SIGINT
No description currently available
21 | Some error returned by waitpid()
No description currently available
22 | Error allocating core memory buffers
No description currently available
23 | Partial transfer due to error
The .SyncPlanetVolumeRoot hidden file was not found in the root directory of the remote storage. The existence of this file is a switch to ensure that the storage is correctly mounted in the directory. Please check if the storage is correctly mounted (after a machine reboot a mount is not automatic or sometimes fails). If it is correctly mounted, please check the permissions on the file, that is has read and write accesses.
Tip
Create this file if it is not created yet (in case of the set up of a new storage)
24 | Partial transfer due to vanished source files
Please check that the files that need to be synchronised are still present in the source storage unit.
25 | The --max-delete limit stopped deletions
30 | Timeout in data send/receive
Please check that your storage unit is properly connected.
35 | Timeout waiting for daemon connection
Please check that your storage unit is properly connected.
127 | Command not found
The rsync command was not found on the remote storage. Please check if the rsync command is installed on the remote storage's machine and that it is accessible in your $PATH. Please install rsync if it is not installed yet.
255 | Connection refused or timeout
The ssh client could not connect to the remote host. The connection was refused or a connection timeout occured. Please check if the storage parameters (hostname, port and username) are correct. ALso check if the remote host is correctly running ssh and listening to the correct port number. Finally, check if the options on the remote firewall are correct.
Note
A typical 255 error is raised when the fingerprint of the storage's host changed:
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ECDSA key sent by the remote host is
SHA256:flwCLxDvuRuvZ6QxeZxzVl1q+JrCco024LhV3vpJn20.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /root/.ssh/known_hosts:1
Password authentication is disabled to avoid man-in-the-middle attacks.
Keyboard-interactive authentication is disabled to avoid man-in-the-middle attacks.
Remove the offending host key as suggested if the host key change was intented and understood.
Legacy Errors (older systems)
Here is a list of errors that should only happen on older systems.
11 | Error in file I/O
On Windows + Cygwin
Error code 11 can be confusing when rsync is started as a service on a Windows platform. It can mean that the pid file for rsync already exists in the C:\Program Files\cwRsyncServer folder (or any other directory where rsync is installed) - although no other info will be given in Windows Event Log. It will become more apparent only if rsync is started as a service from the command line. source (broken)
To fix this error, remove the existing pid file.