File transfer errors

Several different scenarios can cause this type of error, and generally the error message is followed by a system error code that may give a hint at possible place for failure.

Transfer for file is aborted by timeout

Starting with Management Console and Agents v.2.9, error about stuck file transfer may appear
"Transfer for file is aborted by timeout".

When transferring file, Agents exchange torrents with metadata for this file, based on which file pieces will be synced later. If actual file transfer, i.e. upload and download of file pieces, or any other activity on this torrent is suspended for a timeout period, the error is raised. Default timeout is 5 minutes, after which the torrent is removed. New torrent will be created and transfer attempted again later.

Basically this error indicates that agents cannot either upload or download the mentioned file(s). There's no an action-based fix for it as there might be multiple reasons behind it. Initial troubleshooting would include:
- check of overall performance of an agent. Check its disk, RAM and CPU load. That's the most common reason.
- reviewing activity on other jobs by the agent. Perhaps, agent is busy with synchronization of files on other, of higher priority, jobs.
- check the files themselves.

Error is removed when new torrent is created.

Cannot download file: invalid parameter, system error code 22

This error only appears on Linux and *nix-based operating systems and represents the limitation of the file system - the Agent attempts to move a file from temporary location (usually /path/to/your/synced/folder/.sync) to its real place and the operating system refuses to do so.

Here are sample use cases when Linux can return this error code:

There is a non-printable character (for example, ASCII 0x07) in the file or path name which target filesystem does not accept
The target filesystem is Amazon S3 mounted via Amazon gateway and the file path is too long
The target filesystem is a mounted cloud storage and does not accept zero-sized files

How to fix this error

Find the limits of your target filesystem.
Find the corresponding file on your source machine and ensure its path, name or content conforms with target filesystem requirements.

Cannot finish download: problem moving it to its location

When an Agent downloads files, it writes file pieces into .sync directory in the root of sync folder and after download is complete, moves (renames) the file onto its proper location.

The error indicates that this move cannot be done for a reason, which is indicated in the error message. The most common are the following:

1. the root of the directory and the file's designated subdirectory are different logical disks. The only fix to it is to reorganize mount points and keep the whole sync directory with all its subfolders on one logical disk.

2. the storage backend does not support specific symbols. In this case the file won't be moved to its location. For example, LucidLink storage does not support '/', '*', '?', '"', '<', '>', '|', '', ':' and returns system error 2 "No such file or directory". The fix would be to remove the unsupported symbols from the file names and sync them again.

Error code SE_FILE_ENTRY.

Cannot download: the oplock request is denied

Oplock (opportunistic lock) facilitates file access between several applications on a server. The Resilio Agent requests the non-exclusive lock so as to read and sync the file. Non-exclusive means that if some other application also requests the lock while the Agent holds it, the Agent will release the lock.
Some applications hold the exclusive lock, the Agent's request is denied.
Usually this error appears for the files that are configured to delay synchronization with FileDelayConfig and means that the file is still opened in some other application. There's no fix to it other than close that application or wait till the file is available.

Error code SE_FILE_ENTRY.