Linux – Klim Server Blog

Upgrading all packages on OpenWRT

More difficult than on Centos, yeah? 🙂

opkg list-upgradable | cut -f 1 -d ' ' | xargs opkg upgrade

Ivacy VPN strongswan settings for android (and may be iOS)

Hey. I just tried to find out how to setup Ivacy on my android phone but not with OpenVPN or stock Ivacy app.

As we now strongswan app is more battery-friendly. So we should use strongswan. You hear? Use strongswan if its possible.

But googling not give me anything. I asked support and receive half of truth. But figure out the rest by myself. So lets go.

How to install guacamole 1.0.0 on Centos 7 box

Hey. Guacamole – really good app that allow you to connect to PC in your net via RDP/SSH/Telnet/VNC. Lets install it.

yum install cairo-devel libjpeg-devel libpng-devel uuid-devel freerdp-devel pango-devel libssh2-devel libssh-dev tomcat libvncserver-devel libtelnet-devel tomcat-admin-webapps tomcat-webapps gcc terminus-fonts

You can’t upgrade from Centos6 to Centos7

Via redhat-upgrade-tool ?

A lot of articles. And a lot of comments that tool is broken. 🙁

RAMDISK: incomplete write, kernel panic on centos

Today from early morning I was called by my colleague who said that his centos6 box can’t boot after reboot. After grub screen centos show that error:

RAMDISK: incomplete write (6257 != 32768)
write error
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
Pid: 1, comm: swapper not tainted %kernel_ver% #1
Call trace:

Let fix that.

Upgrading MariaDB on Centos7

Hey. I’m already has mariadb installed but it was 5.x version. Today actual version 10.3.x. Lets upgrade!

yum remove mariadb-server mariadb-libs

About root mail

Ok. After fresh install of centos I usually make two commands first

yum remove posftix sendmail
yum install ssmtp

So I just understand that root (and other users mail) I never receive! Lets fix it. Open /etc/aliases with you favorite nano and scroll to the bottom of the file

# Person who should get root's mail
root:           your@serviceemail.com

After that lets test

echo "test message" | mail root

Check your@serviceemail.com. Thats all!

Installing Kernel 5.X with Google BBR support in centos7 box

Install elrepo & new kernel

rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm
yum --enablerepo=elrepo-kernel install kernel-ml -y

Lets understand in which position our new kernel installs. Rows begins with 0, so if you see new kernel on the top you should choose grub-set-default 0

egrep ^menuentry /etc/grub2.cfg | cut -f 2 -d \'
grub2-set-default 0
reboot