Troubleshooting

Linux, UNIX and Windows troubleshooting – Frequently Asked Questions, Help, Hacks, Tips and more

How to reset forgotten root password for Linux KVM qcow2 image/vm

Posted on in Categories , , , last updated February 10, 2018

I have Debian Linux VM running on KVM. I think I forgotten the password for the root account and I am no longer able to run ‘su -‘ command. How do I reset the password for the root account for KVM VM which is in qcow2 format?
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Fix Host ‘IP’ is blocked because of many connection errors on MySQL/MariaDB

Posted on in Categories , , , , , , , last updated November 15, 2017

I am trying to login to my mysql/mysqld server using the following Unix command:
$ mysql -u foo -h 172.16.5.100 -p dbnmame
But greeted with the following error on screen:
ERROR 1129 (HY000): Host ‘172.16.5.100’ is blocked because of many connection errors; unblock with ‘mysqladmin flush-hosts’
How do I fix this problem on a Linux or Unix-like system?

How to prevent sed -i command overwriting my symlinks on Linux or Unix

Posted on in Categories , , , , , , , , , last updated June 13, 2017

I recently ran a command ‘sed -i 's/CONFIG_1/CONFIG_OPT_2/g' /etc/nginx/sites-enabled/*.conf‘ on a Debian Linux server. However, the sed command destroyed the link and created a regular file in place of the link file. How can I prevent my ‘sed -i’ command from destroying symlinks on Linux or Unix-like system?

Ansible: Could not find aptitude. Please ensure it is installed Error and Solution

Posted on in Categories , , , last updated June 13, 2017

I am running the ‘ansible-playbook -i hostnames upgrade.yml‘ command but getting an error that read as follows

fatal: [db1]: FAILED! => {“changed”: false, “failed”: true, “msg”: “Could not find aptitude. Please ensure it is installed.“}

My yml file includes the following line:

- apt: update_cache=yes upgrade=yes

How do I fix this error on a Debian or Ubuntu Linux server?