Once on one high-load access server with about 5 Gb/s traffic in /var/log/syslog, errors began to appear frequently:
Category Archives: Linux
How to transfer a file via XMODEM using Minicom
Run minicom and first connect to the device, execute the command to transfer/receive the file. It is also desirable to specify the data transfer rate of 115200 before the transfer to the device and in minicom to speed up the process otherwise if the speed is 9600, you will have to wait a long time. […]
Install SSL Certificate for iRedMail
Suppose we have a signed SSL certificate, or we will receive it from Let’s Encrypt, as I described in this article:Installing Certbot in Ubuntu To install an SSL certificate for iRedMail, you need to specify it in the Dovecot, Postfix and Apache2 configuration.
Backup MBR in Linux
Master boot record (MBR) — code and data located in the first 512 bytes of the hard disk needed to boot the operating system. From 512 bytes of MBR code contains:446 bytes — Bootstrap64 bytes — Partition table2 bytes — Signature
Installing and using ipset
ipset – a tool consisting of a kernel module, libraries and utility, allowing you to organize a list of networks, IP or MAC addresses, etc., which is very convenient to use for example with IPTables.
IPTables rules for FreeRADIUS
Suppose INPUT is the default DROP, I’ll give examples of IPTables rules for FreeRADIUS:
Changing CPU Scaling Governor on Linux
Through “Scaling Governor”, you can choose the optimal CPU frequency control scheme, which affects power consumption and performance.
How did I make a request to Hetzner to replace the disk in the raid
Already quite often I wrote in Hetzner to replace disks in a raid and in this article I will describe one of the cases. And so, one morning, after a disk dropped out of a raid, mdadm sent me a message by email.
How to configure IP access in nginx?
I will give an example of setting up access by IP in nginx. Suppose you use the standard nginx configuration file, open it in a text editor:
Install and configure Nginx
nginx (engine x) — it is a web server and reverse proxy server, as well as a mail proxy server. Install on Ubuntu with the command: