Category Archives: Administration

Checking restart problems with mysql on centos

You probable installed MySQL with a help of article like this — https://phoenixnap.com/kb/how-to-install-mysql-on-centos-7 So your mysql is controlled by systemctl. Check current status — sudo systemctl status mysqld. Start service — sudo systemctl start mysqld Logs for systemctl are here — sudo journalctl -xe Logs for mysql can be found here — /var/log/mysqld.log. Configs are …

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Letsencrypt — easy way

Now you can install certbot-nginx and it will do everything for you.

And then

If it does not work, try this sudo certbot -d example.com -d www.example.com and then select nginx in a prompt. https://www.digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-centos-7

Install postgresql 11 on CentOs7

Just what to do, no discussion.

How to split disk pool on synology nas

I have a Synology NAS DS 218+. When I bought it, I decided to make a RAID1 pool from two disks. But after time passed, I realized that I don’t have enough space to store all files. And I decided to make two separate disks instead of one RAID1. RAID0 is worse for me comparing …

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Linux. History of system usage

There is a way to monitor your system usage and log to a file easily — with atop command. On my Ubuntu it can be installed with

It can be started as a top command — it’s output almost the same. But the most interesting feature is that it starts a daemon that logs …

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Kubernetes’ cronjobs

That’s what it is — https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/ Get all cronjobs in env:

Get info on exact cronjob:

Get pods with this cronjob:

Get logs of cronjob

you can add -f for live updating logs and -p for watching logs of previous pod.

Crontab time format

That’s about it: min hour day/month month day/week Execution time 30 0 1 1,6,12 * — 00:30 Hrs  on 1st of Jan, June & Dec. 0 20 * 10 1-5 –8.00 PM every weekday (Mon-Fri) only in Oct. 0 0 1,10,15 * * — midnight on 1st ,10th & 15th of month 5,10 0 10 …

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docker-compose example for ceph, kafka, postgres cluster

That is how it can be done:

docker simple starter

Build and run (on linux do not forget sudo):

Login into container

Pipeline view in shell

https://serverfault.com/questions/473905/is-there-a-unix-linux-command-to-count-lines-per-second-from-stdin