Replace defective HDD on CentOS 6 (mbr)

Prologue: sda old but works, sdc defective. I will replace sdc.

First of all, mark disk sdc as defective and remove from raid.

mdadm --manage /dev/md0 --fail /dev/sdc2
mdadm --manage /dev/md1 --fail /dev/sdc1
mdadm --manage /dev/md2 --fail /dev/sdc3
mdadm /dev/md0 -r /dev/sdc2
mdadm /dev/md1 -r /dev/sdc1
mdadm /dev/md2 -r /dev/sdc3

Physically replace disk and copy partition table to new one.

Continue reading “Replace defective HDD on CentOS 6 (mbr)”

Nginx as CDN POP

This released on ubuntu with packages nginx and nginx-extras (some modules used additionally that not avail on Alma packages, that’s why ubuntu).

We will store cached files in /cdncache and logs in /var/log/nginx/cdnlogs.

Our CDN URL is yourcdn1.domain.name for site1.dev and yourcdn2.domain.name for site2.dev

We will server static files (mp4,jpg,png,gif,jpeg,js,ico,html,htm,webp,css,mp3,wav,swf,mov,doc,pdf,xls,ppt,docx,pptx,xlsx,ttf,woff,woff2), accept only GET queries and disallow listing for /.

Continue reading “Nginx as CDN POP”

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.

Continue reading “Ivacy VPN strongswan settings for android (and may be iOS)”

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
Continue reading “How to install guacamole 1.0.0 on Centos 7 box”

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.

Continue reading “RAMDISK: incomplete write, kernel panic on centos”