112 lines
2.7 KiB
ReStructuredText
112 lines
2.7 KiB
ReStructuredText
virt-back: restoring from backups
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#################################
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:date: 2011-08-10 23:20
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:author: Russell Ballestrini
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:tags: Code, DevOps, Guide, Project
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:slug: virt-back-restoring-from-backups
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:status: published
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**In a perfect world we should create backups but never need them.**
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Although this statement holds truth, creating guest backups provides
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many more benefits.
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The most common reasons system administrators restore from a virt-back
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guest backup:
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- recovering from data corruption
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- recovering deleted files
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- recovering from a virus infection
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- recovering from a compromised server
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- backing out a failed change
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- rolling back to a previous state
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- testing disaster recovery plans
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- cloning a server
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- building test environments
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During this article we will cover how to restore a system from a
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virt-back guest backup. This article will not cover how to restore a VM
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host server.
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**Virt-back guest restore procedure**
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In this guide our guest mbison has failed with a major corruption and we
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would like to restore from our backups. We have our running production
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guest images in /KVMROOT and our virt-back guest backups in /KVMBACK. We
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will be restoring the backup on the same hypervisor.
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**Overview:**
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#. Ensure the guest is shut off.
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#. move the bad image file out of the way
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#. untar the virt-back backup into place
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#. power up the guest
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**Detailed Procedure:**
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#. Verify the guest is shut off by running:
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::
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virt-back --info-all
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#. We noticed that mbison was still running so we invoked:
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::
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virt-back --shutdown mbison
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#. Move the corrupted image file out of the way:
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::
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mv /KVMROOT/mbison.img /KVMROOT/mbison.img.NFG
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#. Unzip and unarchive the backup using the following command:
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::
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sudo tar -xzvf /KVMBACK/mbison.tar.gz -C /KVMROOT --strip 1
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#. When the untar completes, start the guest:
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::
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virt-back --create mbison
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#. Connect to the guest over SSH and verify that all required services
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and applications start. Determine if the restore was successful.
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**Restore guest backup on new hypervisor:**
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The details in this section were adapted from a tutorial given by
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`Fabian Rodriguez <http://fabianrodriguez.com/>`_.
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#. Re-create any bridge network interfaces on new hypervisor
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(/etc/network/interfaces for Debian)
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#. Adjust mbison.xml if needed (for example if you are changing paths)
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::
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sudo mkdir /KVMROOT
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sudo tar -xvzf mbison.tar.gz -C /KVMROOT --strip 1
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virsh create /KVMROOT/mbison.xml
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**Note:** We use virsh create instead of virt-back create. While both
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commands start guest DOMs, virsh create will also register the DOM into
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the hypervisor.
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.. contents::
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