RSYNC is a powerful tool that is often utilized by system administrators to synchronize files to a remote server or between local directories. Despite its usefulness, it occasionally throws the “read error,” which can have several potential causes and resolutions.
One common reason for the RSYNC read error might be due to a lack of sufficient permissions. When run as a normal user, RSYNC might not be able to read certain files which require administrative or root permissions. To get past this roadblock, consider running RSYNC as the root user, or modifying the permissions of the pertinent files or directories with the chmod command (Linux.com, 2018). Still, always carefully consider the implications of changing file permissions and only do it if necessary and safe.
Another potential cause of the read error could be due to file inaccessibility originating from a currently running service or application. For instance, if you’re trying to sync a database file that’s currently being used by a running database service, RSYNC might not be able to read the file. Possible solutions include stopping the service, syncing, then restarting the service again. Alternatively, you might want to look into using a tool like rsnapshot, which can create a snapshot of the file system and sync that instead (RSYNC.net, 2020).
Issues with the file system itself might also lead to read errors. Corruption, unexpected inconsistencies, or damage in the file system can be a source of read errors by RSYNC. Tools like fsck on Unix/Linux-based systems can be used to check and repair the consistency of the file system (ibm.com, 2013). Always remember to back up important files before running these tools, as they might result in data loss.
Network problems can also cause RSYNC read errors. Network instability, bandwidth limitations, or overall poor connection quality can interrupt the synchronization process. The RSYNC —partial option can be useful here, allowing RSYNC to keep partially transferred files if the connection breaks, and continue from where it left off when resumed (linux.die.net man pages, 2020).
Finally, another solution could be to update the RSYNC version as outdated versions might have bugs leading to these errors, as indicated in the discussions on the Serverfault platform (2019).
In conclusion, RSYNC read errors may occur due to a variety of reasons. Therefore, the resolution could be from a change in permissions, addressing file accessibility, file system corrections, dealing with network problems, or updating RSYNC itself. Adequate knowledge and combination of these solutions will enhance your efficiency in dealing with RSYNC read errors.
Sources:
Linux.com (2018), Linux 101: How to give a user sudo rights
Rsync.net (2020), rsync.net: Product Overview
IBM.com (2013), File system checkers
Man7.org (2020), Rsync man page
Serverfault (2019), rsync throwing error “unable to read from monitor: Connection reset by peer (104)”
