Difference between revisions of "Backup"

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(merge Editing Backing up disk image via SSH.)
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A full backup is only possible while in the rescue image, and there is often not enough tmp space to use as a destination, so it needs to be copied over the network directly to the destination. One way is to setup a special account with its own password or ssh keys on the backup destination server, then pipe tar or gzip through ssh. This works with a filesystem image directly from or to a partition, or with tar and a mounted filesystem.  (Some more details: [[Backing_up_disk_image_via_SSH]])
 
A full backup is only possible while in the rescue image, and there is often not enough tmp space to use as a destination, so it needs to be copied over the network directly to the destination. One way is to setup a special account with its own password or ssh keys on the backup destination server, then pipe tar or gzip through ssh. This works with a filesystem image directly from or to a partition, or with tar and a mounted filesystem.  (Some more details: [[Backing_up_disk_image_via_SSH]])
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== Editing Backing up disk image via SSH ==
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backing up new system to another server ...
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my current procedure to grab compressed disk image:
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* boot to Centos rescue image (described on the [[Password Reset]] page)
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* mkdir /tmp/xvda1
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* mount /dev/xvda1 /tmp/xvda1
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* dd if=/dev/zero of=/tmp/xvda1/big_blank_file
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* rm /tmp/xvda1/big_blank_file
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* umount /tmp/xvda1
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* bzip2 < /dev/xvda1 | ssh me@my.other.server.tld "cat > xvda1_backup.bz2"
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(The "big_blank_file" finagling for compressability may be not particularly necessary on a fresh image ...)  With the zero-pad prep, a fresh Debian Lenny image (about 500 MB installed on a 12 GB disk) compresses down to less than 185 MB.  After installing Apache2 and some user data, the disk image compressed from about 750 MB down to about 250 MB - without repeating the zero-pad prep.
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Alternatively, you might do something like this:
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* boot to Centos rescue image
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* e2fsck -f /dev/xvda1
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* resize2fs -M /dev/xvda1
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* bzip2 < /dev/xvda1 | ssh me@my.other.server.tld "cat > xvda1_backup.bz2"
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Which has the added benefit of downsizing the partition to its smallest possible size (i.e., completely full), so if you are restoring to a smaller device, you will not fill up the device with unused space.
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(see [[Backup]] for more on backups in general, and [[Restore]] to restore this image)
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{{u}}
  
 
Also, see [[Restore]]
 
Also, see [[Restore]]
 
[[Category:for Users]]
 
[[Category:for Users]]
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{{c|Getting Started}}
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{{c|User Questions}}
 
{{c|Backup}}
 
{{c|Backup}}

Revision as of 19:03, 28 June 2017

What are some ways to backup the vps? How should a backup be done while in the rescue image or while the vps is running?

A full backup is only possible while in the rescue image, and there is often not enough tmp space to use as a destination, so it needs to be copied over the network directly to the destination. One way is to setup a special account with its own password or ssh keys on the backup destination server, then pipe tar or gzip through ssh. This works with a filesystem image directly from or to a partition, or with tar and a mounted filesystem. (Some more details: Backing_up_disk_image_via_SSH)

Editing Backing up disk image via SSH

backing up new system to another server ...

my current procedure to grab compressed disk image:

  • boot to Centos rescue image (described on the Password Reset page)
  • mkdir /tmp/xvda1
  • mount /dev/xvda1 /tmp/xvda1
  • dd if=/dev/zero of=/tmp/xvda1/big_blank_file
  • rm /tmp/xvda1/big_blank_file
  • umount /tmp/xvda1
  • bzip2 < /dev/xvda1 | ssh me@my.other.server.tld "cat > xvda1_backup.bz2"

(The "big_blank_file" finagling for compressability may be not particularly necessary on a fresh image ...) With the zero-pad prep, a fresh Debian Lenny image (about 500 MB installed on a 12 GB disk) compresses down to less than 185 MB. After installing Apache2 and some user data, the disk image compressed from about 750 MB down to about 250 MB - without repeating the zero-pad prep.

Alternatively, you might do something like this:

  • boot to Centos rescue image
  • e2fsck -f /dev/xvda1
  • resize2fs -M /dev/xvda1
  • bzip2 < /dev/xvda1 | ssh me@my.other.server.tld "cat > xvda1_backup.bz2"

Which has the added benefit of downsizing the partition to its smallest possible size (i.e., completely full), so if you are restoring to a smaller device, you will not fill up the device with unused space.

(see Backup for more on backups in general, and Restore to restore this image)

Also, see Restore