Remove redundant self-compiled kernels, MySQL is not connected to the problem

1. Remove the extra self-compiled kernel

Each time the Debian release kernel updates, there are always some kernel options that do not match their own hardware, to compile the kernel themselves. The extra kernel takes up extra hard disk space. I tried to cause the kernel to fail because the/boot partition is full.
In order to free up limited resources, it is necessary to remove the redundant kernel.

See that uninstalling your own compiled kernel found a viable method.

The main idea is to delete the extra files in the/lib/modules/,/boot folder, and then update grub.

Below is

Multiple self-compiled kernels before deletion

Delete/lib/modules/,/boot files below

Because every time I compile, I always put the newest kernel to/usr/src, so I omitted to delete the redundant source code in/USR/SRC. If you do not do so, please delete the redundant source code yourself.

Update Grub

Reboot, take a look.

As you can see, 5 cores have been reduced to 2 after the above operation. The operation was successful.

2.mysql not connected to the problem

Yesterday, we encountered a strange phenomenon, our MySQL server has the problem of Erlang connectivity, the personal feel that it is necessary to record a bit.
Operating system: Debian 6 x86_64
MySQL version: 5.1.66

Problem phenomenon:
MySQL has not reached the maximum number of connections, using the command line can be connected to retrieve the database inside there is no problem, the JDBC connection is not a problem. However, Erlang uses a TCP connection, and the TCP connection is immediately closed on the first connection.
Then try to focus on the MySQL server, restart the process more than a message:

 for corrupt, not cleanly closed and upgrade needing tables.

After several hours of tossing and finding, the following command is useful:

Dpkg-reconfigure mysql-server-5.1

For more information, refer to re:fixing corrupt MySQL table