Thursday, January 12, 2017

Lets Automate Kdump

Kdump is kernel crash dumping mechanism and is very reliable because the crash dump is captured from the context of a freshly booted kernel and not from the context of the crashed kernel. Kdump uses Kexec to boot into a second kernel whenever system crashes. This second kernel, often called a capture kernel, boots with very little memory and captures the dump image.

Monday, November 21, 2016

Create & Restore Linux System Data Using Dump Command

I was searching for a simple backup solution in Linux system that could serve in block-level backup and for disaster recovery as well, and simply cost effective. Now-e-days, one could see a lot of options, however, I wanted to try out simple and yet native Linux solution, so, I came across this "dump & restore" utility.  This may not be an ideal solution for a larger network, but one could leverage on this for smaller network wherein there is no tight schedule on recovery. So, I thought of creating a step-by-step document of the same.

Complete system can be backed up and restored using native Linux commands “dump & restore” which would facilitate backup or disaster recovery process.

Thursday, November 3, 2016

Rear- Linux Disaster Recovery Solution

Rear” (Relax-and-Recover) fits perfect in implementing a bare metal disaster recovery solution & image migration as well.  Rear is the leading Open Source disaster recovery solution. It is a modular framework with many ready-to-go workflows for common situations.

Most backup software solutions are very good at restoring data but do not support recreating the system layout. It is very good at recreating the system layout but works best when used together with supported backup software.

Sunday, July 31, 2016

Kickstart Implementation In Linux Without PXE

Steps of doing automated kickstart installation on RHEL systems  without  PXE boot and using static IP address.

Some Key Points:-

- Kickstart is ideally be suited for DHCP based environment with PXE enabled network cards.

- If there is no PXE enabled network card then initial manual effort is required.

- Kickstart would use NetworkManager (NM) deamon for initial fetch of “*.cfg” file and boot files over network.

- If NM is not required on a new system then this would need post kickstart task of disabling it.

Sunday, January 24, 2016

Main Differences Between Linux & Solaris

Default Shell/bin/bash (/bin/sh would typically symlinked to bash)/bin/sh

File System
Ext2/3/4 or XFS (RHEL 7)
UFS - Unix File System and VxFS,QFS & ZFS (Solaris 10 onwards) also supported.