During writes to Redis ( SET foo bar ) I am getting the following error:
MISCONF Redis is configured to save RDB snapshots, but is currently not able to persist on disk. Commands that may modify the data set are disabled. Please check Redis logs for details about the error.
Basically I understand that the problem is that redis is not able to save data on the disk, but have no idea how to get rid of the problem.
Also the following question has the same problem, it is abandoned long time ago with no answers and most probably no attempts to solve the problem.
In case you encounter the error and some important data cannot be discarded on the running redis instance (problems with permissions for the rdb file or its directory incorrectly, or running out of disk space), you can always redirect the rdb file to be written somewhere else.
Using redis-cli, you can do something like this:
CONFIG SET dir /tmp/some/directory/other/than/var
CONFIG SET dbfilename temp.rdb
After this, you might want to execute a BGSAVE command to make sure that the data will be written to the rdb file. Make sure that when you execute INFO persistence, bgsave_in_progress is already 0 and rdb_last_bgsave_status is ok. After that, you can now start backing up the generated rdb file somewhere safe.
Obviously, you should also have the dbfilename and dir changes reflected on the actual config file that you're using afterwards.