Chủ Nhật, 4 tháng 12, 2016

Bypassing Bad fstab Failure When Booting Linux

If /etc/fstab file is created with errors or the hardware configuration changes such as adding hard disks, Linux will boot into failure state. We can bypass the fstab failure by adding booting parameters to Linux. We can do this in two methods:

Method 1: Boot to single user mode 

When booting into single user mode, Linux will not mount anything. Then we can remount the / to some directory in read/write mode and then edit the /etc/fstab.
1. Boot Linux into single user mode
Press ESC in the grub menu and press ‘e’ to edit the grub entry. Add single to the kernel parameter like this:
kernel /vmlinuz-2.6.32.21-166.fc12.i686 ro root=/dev/mapper/VolGroup-LogVol00 vga=792 single

How To Reset Root Password On CentOS 7

The way to reset the root password on centos7 is totally different to Centos 6. Let me show you how to reset root password in CentOS 7.
1 – In the boot grub menu select option to edit.
Selection_003
2 – Select Option to edit (e).

Reset Your Forgotten Root Password On RHEL 7

Sometimes you forget stuff like meetings, seminars,passwords etc. I do. But forgetting a password to a Servers with no easy way to reset it while locked outRedhat servers is one of such systems. If you forget the root password to your RHEL 7 SERVERS, it’s almost virtually impossible to reset it while you’re locked out.

At the boot menu, press e to edit the existing kernel . Then, go to the kernel line (the line starting with linux16) .

How To Setup MariaDB Galera Cluster

MariaDB is a relational database management system (RDBMS) and  MariaDB Galera Cluster is a synchronous multi-master cluster for MariaDB. It is available on Linux only, and only supports the XtraDB/InnoDB storage engines. This article explains how to setup MariaDB Galera Cluster 10.0 with 2 nodes running on CentOS 6.5 x86_64 resulting in a HA (high-availability) database cluster.

How to Deploy and Configure MaxScale for SQL Load Balancing with Read-Write Split

There are two models of load balancing: transport and application layer. HAProxy is a great TCP load balancer, but it’s lack of SQL awareness effectively limits its ability to address certain scaling issues in distributed database environments. In the open source world, there’s been a few SQL-aware load balancers, namely MySQL Proxy, ProxySQL and MaxScale, but they all seemed to be in beta status and unfit for production use. So we were pretty excited when the MariaDB team released a GA version of MaxScale earlier this year. In this blog, we’ll have a look at MaxScale and see how it compares with HAProxy.

Proxmox VE- One Public IP

Proxmox VE - One Public IP
This guide will show you how to set up Proxmox with only one public IP. We will configure an extra interface bridge and make sure VM traffic is NATed. I have a few dedicated servers, some run Proxmox. Most of them however have only a few IP's. Therefore the VM's in proxmox cannot all have a public IP. For most of them that is not a problem. If needed I run a proxy or set up iptables to forward ports to the VM's.
This guide is tested on a proxmox machine running proxmox version 3.2.

Proxmox VE_part 1

Proxmox VE (virtual environment) is a distribution based on Debian Etch (x86_64); it provides an OpenSource virtualization platform for running virtual machines (OpenVZ and KVM) and comes with a powerful, web-based control panel (it includes a web-based graphical console that you can use to connect to the virtual machines). With Proxmox VE, you can even create a cluster of virtualization hosts and create/control virtual machines on remote hosts from the control panel. Proxmox VE also supports live migration of virtual machines from one host to the other. This guide shows how you can use Proxmox VE to control KVM and OpenVZ virtual machines and how to create a small computing cloud with it