Did your daily backup ended up with Rsync error code 11?

The error code description says it’s an error with the file I/O.

Basically, rsync error 11 occurs when the disk space is full or if the system cannot detect the external drive.

At Bobcares, we often get requests to fix rsync errors, as a part of our Server Management Services.

Today, let’s see how our Support Engineers fix this rsync error.

What is Rsync error code 11?

Rsync is a useful tool in syncing files both locally and remotely. The most common use of Rsync comes during backing up of files. Recently, during a backup operation, one of our customers got an error message. The rsync error message was:

rsync: write failed on "/home/xxxxxx/backup/daily/bandwidth_db.json": No space left on device (28)
rsync error: error in file IO (code 11) at receiver.c(301) [receiver=3.0.6]
rsync: connection unexpectedly closed (53 bytes received so far) [generator]
rsync error: error in rsync protocol data stream (code 12) at io.c(600) [generator=3.0.6]

This message indicates that there is no space left in the disk to copy some files. So, the basic reason for the termination of the rsync operation was error code 11.

For instance, the error code 11 denotes Error in the file I/O. This is a tricky error. It doesn’t specify the reason for the error. But our Dedicated Engineers with expertise over a decade fixed this error for our customers.

How we fix the rsync error 11?

Let’s now check on how we normally fix the rsync error 11.

Basically, the rsync error exit with code 11 when the disk space is full. So, when customers approach us with this error code initially we check for the server disk space.

For instance, we check the disk space of the backup server using the command,

df -h

This command displays the total disk usage in human-readable form. From the results, we found that the /home directory of the user was 100% used. So, when the rsync backup file to it, the user got error 11.

Hence it is necessary to clear, some irrelevant data or adds extra disk space to the server. To analyze disk usage at the directory level, we execute the command,

du -sch *

Here the options used are:

• -s indicates –summarize which display only a total for each argument.
• -c produces a grand total of the space used.
• -h displays the disk space in human-readable form.

After clearing some unwanted data the issue resolved.

Yet another reason for this error is the non-detection of hard disk in the system. In this case, the rsync operation copies all files to RAM. When the RAM is full, users get the error 11.

So, our Support Engineers recommend changing the system configuration. Usually, this involves changing the way that connects the hard drive or disk to the computer. For instance, it requires the hard disk to operate in AHCI mode which can write data at higher speeds.

How we prevent disk full errors?

When the root cause itself is 100% disk usage, avoiding such a scenario really helps. That’s why our Dedicated Engineers do the following to prevent Rsync error code 11.

1. Keep a regular watch on the Rsync progress
2. Use monitoring scripts to constantly evaluate disk space on the server. Ideally, we set up a script to alert us via email when the free disk space falls below a preset value.
3. For large migration, we always do it in batches. This would help us to have better tracking.
4. Systematic cleanup of backups related to already restored data.

[Having trouble in fixing rsync errors? – We’ll fix it for you.]

Conclusion

In short, rsync error code 11 usually indicates that the disk space is full. Hence, the rsync operation terminates without the complete file transfer. Today, we saw how our Support Engineers fix this error and proactively avoid it.