Stuck with the error, R1Soft “Unable to open snapshot device”? We can help you.

During backup, the Agent may stop and un-mount the snapshot, immediately try to read from it, and fail.

As part of our Server Management Services, we assist our customers with several R1soft queries.

Today, let us see how to fix this error effectively.

R1Soft unable to open snapshot device

[2012-Jan-25 23:02:10],[DEBUG],[69.65.17.179:46006],Un-mounting snapshot device /dev/hcp1 [2012-Jan-25 23:02:10],[ INFO],[69.65.17.179:46006],Stopping snapshot for device ‘/dev/sda3’ with id 1 try 0 [2012-Jan-25 23:02:10],[ INFO],[69.65.17.179:46006],Snapshot for device ‘/dev/sda3’ with id 1 stopped! [2012-Jan-25 23:02:10],[ERROR],[69.65.17.179:46006],An exception occurred during the request. Unable to open snapshot device ‘/dev/hcp1’ for replication.: No such file or directory

Generally, this error occurs in some systems that make use of jailed shell environments (such as cPanel).

The major intention behind it is mainly to improve the security of the systems.

What happens here is that the CDP agent is not aware of virtual mounts existing such as /home/virtfs/$user/cdp1. This will eventually cause backups to fail.

How to fix this error?

Moving ahead, let us see how our Support Techs fix this error.

Solution 1:

Usually, the resolution is relatively simple, we can perform the fix with a one-liner. However, we need to ensure that there’s no active backup running.

To find the same, we run:

[bash]hcp -l[/bash]

Once done, we execute the following:

[bash]cat /proc/mounts | grep cdp | awk ‘{print $2}’ | xargs umount[/bash]

Then we rerun the r1soft backup. Which should eventually be working again.

Solution 2:

Another possible solution for this error is to reboot the server.

Solution 3:

On the other hand, rebooting webservers unnecessarily in a shared environment is not a great idea. It can lead to cache loss in the machine and the database.

This can result in an outage for 15 minutes or so whilst the server performs very poorly by comparison.

Thus another solution is to Reinitialize CageFS with the command below:

# cagefsctl --reinit

[Need help with the fix? We are here for you]

Conclusion

In short, we saw how our Support Techs fix this error for our customers.