MySQL/Writing file error (Errcode 28)

Use the perror command:

$ perror 28
OS error code  28:  No space left on device

Unless error codes are different on your system, your file system is full.

We have experienced similar issue, and the problem was MySQL used /tmp directory for its needs (it's default configuration). And /tmp was located on its own partition, that had too few space for big MySQL requests.

For more details take a look for this answer: https://stackoverflow.com/a/3716778/994302

I had same problem but disk space was okay (only 40% full). Problem were inodes, I had too many small files and my inodes were full.

You can check inode status with df -i

The error means that you dont have enough space to create temp files needed by MySQL.

The first thing you can try is to expand the size of your /tmp/ partition. If you are under LVM, check the lvextend command.

If you are not able to increase the size of your partition /tmp/ you can work in the MySQL configuration, edit the my.cnf (typically on /etc/mysql/my.cnf) file and look for this line:

tmpdir = /tmp/

Change it for whatever you want (example /var/tmp/). Just be sure to have space and assign write permission for the mysql user in the new directory.

Hope this helps!

Run the following code:

du -sh /var/log/mysql

Perhaps mysql binary logs filled the memory, If so, follow the removal of old logs and restart the server. Also add in my.cnf:

expire_logs_days = 3