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Relax-and-Recover - Linux bare metal disaster recovery and system migration solution (cfr. mksysb, ignite)
https://github.com/rear/rear

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Relax-and-Recover - Linux bare metal disaster recovery and system migration solution (cfr. mksysb, ignite)

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README 

        
Relax-and-Recover

=================



Relax-and-Recover is the leading Open Source bare metal disaster recovery

and system migration solution. It is a modular framework with many

ready-to-go workflows for common situations.



Relax-and-Recover produces a bootable image. This image can repartition the

system. Once that is done it initiates a restore from backup. Restores to

different hardware are possible. Relax-and-Recover can therefore be used as a

migration tool as well.



Currently Relax-and-Recover supports various boot media (incl. ISO, PXE,

OBDR tape, USB or eSATA storage), a variety of network protocols (incl.

sftp, ftp, http, nfs, cifs) as well as a multitude of backup strategies

(incl. IBM TSM, CommVault, Micro Focus Data Protector, Symantec NetBackup, <>, Bacula, rsync, Borg).



Relax-and-Recover was designed to be easy to set up, requires no maintenance

and is there to assist when disaster strikes. Its setup-and-forget nature

removes any excuse for not having a disaster recovery solution implemented.



Recovering from disaster is made straightforward by a 2-step recovery

process so that it can be executed by operational teams when required.

When used interactively (e.g. when used for migrating systems), menus help

make decisions to restore to a new (hardware) environment.



Extending and integrating Relax-and-Recover into complex environments is made

possible by its modular framework. Consistent logging and optionally extended

output help understand the concepts behind Relax-and-Recover, troubleshoot

during initial configuration and help debug during integration.



<>



See <> for more detailed information about Relax-and-Recover.



REQUIREMENTS

------------

Relax-and-Recover is written entirely in Bash and does not require any

external programs.  However, the rescue system that is created by

Relax-and-Recover requires some programs that are needed to make our

rescue system work:



 - mingetty or agetty

 - sfdisk or parted

 - grub2-efi-modules or similar package that provides Grub2 modules (/usr/lib/grub(2)/) if USB recovery on EFI is used



All other required programs (like sort, dd, grep, etc.) are so common, that

we don't list them as requirements. In case your specific workflow requires

additional tools, Relax-and-Recover will tell you.



QUICK START GUIDE

-----------------

This quick start guide shows how to run Relax-and-Recover from the git checkout

and create a bootable USB backup and rescue medium.



Start by cloning the Relax-and-Recover sources from GitHub:



    git clone https://github.com/rear/rear.git



Move into the 'rear/' directory (it gets created by 'git clone'):



    cd rear/



Prepare your USB medium.

Change /dev/sdX to the correct device in your environment.

Relax-and-Recover will 'own' the whole device.



***This will destroy all data on that device.***



    sudo usr/sbin/rear format /dev/sdX



Relax-and-Recover asks you to confirm that you want to format your USB device:



    Yes



The device gets labeled REAR-000 by the 'rear format' workflow.



Now edit the 'etc/rear/local.conf' configuration file:



----

### write the rescue initramfs to USB and update the USB bootloader

OUTPUT=USB



### create a backup using the internal NETFS method, using 'tar'

BACKUP=NETFS



### write both rescue image and backup to the device labeled REAR-000

BACKUP_URL=usb:///dev/disk/by-label/REAR-000

----



Ensure you have at least defined the +OUTPUT+, +BACKUP+ and +BACKUP_URL+ variables.



Now you are ready to create a ReaR rescue image on your USB device.

We want verbose output (-v option):



    sudo usr/sbin/rear -v mkrescue



The output you get will look like this:

----

Relax-and-Recover 

Using log file: /var/log/rear/rear-.log

Creating disk layout

Creating root filesystem layout

Copying files and directories

Copying binaries and libraries

Copying kernel modules

Creating initramfs

Writing MBR to /dev/sdX

Copying resulting files to usb location

----



You may check the log file for possible errors or see more details what Relax-and-Recover is doing.



Now reboot your system and verify that you can boot the ReaR rescue environment from your USB device as a test.

In the ReaR rescue environment log in as 'root' (no password) and directly shut it down (it was only a test).

Again boot your normal system.



In your normal system (with your 'REAR-000' labeled USB rescue device connected)

create a backup of your system (provided your USB device has enough space) by using:



    sudo usr/sbin/rear -v mkbackup



The output you get will look like the above but now with a backup done at the end.



When all went well (also check the log file),

you have a bootable USB rescue medium with a backup of your system.



You are now better prepared for disaster recovery.



If your system got destroyed you can boot from your USB backup and rescue medium,

log in as 'root' into the ReaR rescue environment and call 'rear -v recover'.

This will completely re-create your system from scratch and restore your backup

which will destroy and overwrite all previously existing data on your system disk.

So to test if 'rear recover' works, you need fully compatible replacement hardware

where you can verify that 'rear recover' works (at least on your replacement hardware).



INSTALLATION

------------

On RPM based systems you should use the 'rear' RPM package.



Preferably obtain it as described on the Relax-and-Recover homepage

http://relax-and-recover.org/download/



Alternatively as a software developer you may manually build it from the source tree with:



   make rpm



This will create an RPM for your distribution.

The RPM is not platform-dependent and should work also on other RPM based distributions.



On DEB based systems you can execute the command:



  make deb



Alternatively as a software developer you may install manually via:



  make install



Do not mix different installation methods.

You should remove a package before doing a manual installation.



CONFIGURATION

-------------

To configure Relax-and-Recover you have to edit the configuration files in

'/etc/rear/'. All '*.conf' files there are part of the configuration, but

only 'site.conf' and 'local.conf' are intended for the user configuration.

All other configuration files hold defaults for various distributions and

should not be changed.



In '/etc/rear/templates/' there are also some template files which are use by

Relax-and-Recover to create configuration files (mostly for the boot

environment). You can use these templates to prepend your own configurations

to the configuration files created by Relax-and-Recover, for example you can

edit 'PXE_pxelinux.cfg' to add some general pxelinux configuration you use

(I put there stuff to install Linux over the network).



In almost all circumstances you have to configure two main settings and their

parameters: The +BACKUP+ method and the +OUTPUT+ method.



The backup method defines how your data is to be saved and whether Relax-and-Recover

should backup your data as part of the mkrescue process or whether you use an

external application, e.g. backup software to archive your data.



The output method defines how the rescue system is written to disk and how you

plan to boot the failed computer from the rescue system.



See '/usr/share/rear/conf/default.conf' for an overview of the possible methods

and their options. An example to use TSM for backup and PXE for output and

would be to add these lines to '/etc/rear/local.conf':



----

BACKUP=TSM

OUTPUT=PXE

----



And since all your computers use NTP for time synchronisation, you should also

add these lines to '/etc/rear/site.conf':



----

TIMESYNC=NTP

----



Don't forget to distribute the 'site.conf' to all your systems.



The resulting PXE files (kernel, initrd and pxelinux configuration) will be

written to files in '/var/lib/rear/output/'. You can now modify the behaviour

by copying the appropriate configuration variables from 'default.conf' to

'local.conf' and changing them to suit your environment.



USAGE

-----

To use Relax-and-Recover you always call the main script '/usr/sbin/rear':



----

# rear help



Usage: rear [-h|--help] [-V|--version] [-dsSv] [-D|--debugscripts SET] [-c DIR] [-C CONFIG] [-r KERNEL] [-n|--non-interactive] [-e|--expose-secrets] [-p|--portable] [--] COMMAND [ARGS...]



Relax-and-Recover comes with ABSOLUTELY NO WARRANTY; for details see

the GNU General Public License at: http://www.gnu.org/licenses/gpl.html



Available options:

 -h --help              usage information (this text)

 -c DIR                 alternative config directory; instead of /src/rear/etc/rear

 -C CONFIG              additional config files; absolute path or relative to config directory

 -d                     debug mode; run many commands verbosely with debug messages in log file (also sets -v)

 -D                     debugscript mode; log executed commands via 'set -x' (also sets -v and -d)

 --debugscripts SET     same as -d -v -D but debugscript mode with 'set -SET'

 -r KERNEL              kernel version to use; currently '5.15.0-204.147.6.3.el9uek.x86_64'

 -s                     simulation mode; show what scripts are run (without executing them)

 -S                     step-by-step mode; acknowledge each script individually

 -v                     verbose mode; show messages what Relax-and-Recover is doing on the terminal or show verbose help

 -n --non-interactive   non-interactive mode; aborts when any user input is required (experimental)

 -e --expose-secrets    do not suppress output of confidential values (passwords, encryption keys) in particular in the log file

 -p --portable          allow running any ReaR workflow, especially recover, from a git checkout or rear source archive

 -V --version           version information



List of commands:

 checklayout     check if the disk layout has changed

 dump            dump configuration and system information

 format          Format and label medium for use with ReaR

 mkbackup        create rescue media and backup system

 mkbackuponly    backup system without creating rescue media

 mkopalpba       create a pre-boot authentication (PBA) image to boot from TCG Opal 2-compliant self-encrypting disks

 mkrescue        create rescue media only

 mountonly       use ReaR as live media to mount and repair the system

 opaladmin       administrate TCG Opal 2-compliant self-encrypting disks

 recover         recover the system

 restoreonly     only restore the backup

 validate        submit validation information

Use 'rear -v help' for more advanced commands.

----



To view/verify your configuration, run +rear dump+. It will print out the

current settings for +BACKUP+ and +OUTPUT+ methods and some system information.



To create a new rescue environment, simply call +rear mkrescue+. Do not forget

to copy the resulting rescue system away so that you can use it in the case of

a system failure. Use +rear mkbackup+ instead if you are using the builtin

backup functions (like +BACKUP=NETFS+)



To recover your system, start the computer from the rescue system and run

+rear recover+. Your system will be recovered and you can restart it and

continue to use it normally.



AUTHORS AND MAINTAINERS

-----------------------



The ReaR project was initiated in 2006 by https://github.com/schlomo[Schlomo Schapiro] and https://github.com/gdha[Gratien D'haese] and has since then seen a lot of contributions by many authors. As ReaR deals with bare metal disaster recovery, there is a large amount of code that was contributed by owners and users of specialized hardware and software. Without their combined efforts and contributions ReaR would not be the universal Linux bare metal disaster recovery solution that it is today.



As time passed the project was lucky to get the support of additional developers to also help as maintainers: https://github.com/dagwieers[Dag Wieers], https://github.com/jhoekx[Jeroen Hoekx], https://github.com/jsmeix[Johannes Meixner], https://github.com/gozora[Vladimir Gozora], https://github.com/schabrolles[Sébastien Chabrolles], https://github.com/rmetrich[Renaud Métrich] and https://github.com/pcahyna[Pavel Cahyna]. We hope that ReaR continues to prove useful and to attract more developers who agree to be maintainers. Please refer to the link:MAINTAINERS[MAINTAINERS] file for the list of active and past maintainers.



To see the full list of authors and their contributions please look at the https://github.com/rear/rear/graphs/contributors[git history]. We are very thankful to all authors and encourage anybody interested to take a look at our source code and to contribute what you find important.



REFERENCES

----------



* http://relax-and-recover.org/documentation/[Relax-and-Recover Documentation]

* http://relax-and-recover.org/support/[Relax-and-Recover Support]

* http://relax-and-recover.org/events/[Relax-and-Recover Events]

* https://github.com/rear/rear/issues[Relax-and-Recover Issues]

* http://relax-and-recover.org/support/sponsors[Relax-and-Recover Sponsoring]

* https://docs.bareos.org/Appendix/DisasterRecoveryUsingBareos.html[Disaster Recovery Using Bareos]