Solving the “404 Not Found …” error when upgrading old Linux versions

I installed Kubuntu 11.04 once, although version 14.04 was already available for downloading on the official website, but there were no other carriers at hand, so I decided to install the old one and then upgrade.

Continue reading “Solving the “404 Not Found …” error when upgrading old Linux versions”

Recovering MySQL InnoDB after power failure

Once, after the power was turned off, the UPS was discharged, then the generator automatic start did not work because it turned on and off several times, as a result, the server with MySQL was also started and disconnected from the power supply several times, later the tables of different databases were damaged , including the default database with mysql users, as a result, the MySQL daemon did not start.

Continue reading “Recovering MySQL InnoDB after power failure”

How to roll back the kernel version on Ubuntu

Sometimes after updating the kernel of the system, some important services start to work incorrectly and in order not to look for a problem on the combat server, and to do it for example later on the virtual one, you can boot the system from the previous version of the kernel.

Continue reading “How to roll back the kernel version on Ubuntu”

Why is the GRUB installed on a flash drive when installing Linux?

By default, the GRUB boot loader is installed on the first disk in the system, it is usually a hard disk, but on some servers with RAID controllers I noticed that when you turn on the server, select the USB flash drive in the Boot menu, of course, to boot from it, it becomes the first disk, then there is /dev/sda and at the end of the system installation the bootloader is installed on it.

Continue reading “Why is the GRUB installed on a flash drive when installing Linux?”

Abills. Solving the error Cannot change column ‘id’: used in a foreign key constraint ‘users_contacts_ibfk_2’

Once executed db_check.pl on a server with Abills 0.78.16:

Continue reading “Abills. Solving the error Cannot change column ‘id’: used in a foreign key constraint ‘users_contacts_ibfk_2’”