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Saturday, October 30, 2010

Partimage

About partimage

Partimage is opensource disk backup software. It saves partitions having a supported filesystem on a sector basis to an image file. Although it runs under Linux, Windows and most Linux filesystems are supported. The image file can be compressed to save disk space and transfer time and can be split into multiple files to be copied to CDs or DVDs.

Partitions can be saved across the network using the partimage network support, or using Samba / NFS (Network File Systems). This provides the ability to perform an hard disk partition recovery after a disk crash.

Partimage can be run as part of your normal system or as a stand-alone from the live SystemRescueCd. This is helpful when the operating system cannot be started. SystemRescueCd comes with most of the data recovery software for linux that you may need.

Partimage will only copy data from the used portions of the partition. (This is why it only works for supported filesystem). For speed and efficiency, free blocks are not written to the image file. This is unlike other commands, which also copy unused blocks. Since the partition is processed on a sequential sector basis disk transfer time is maximized and seek time is minimized ,Partimage also works for very full partitions. For example, a full 1 GB partition may be compressed with d own to 400MB.

When to use it

  • Very useful to restore partitions for recovery if there is a problem like virus infection, file system errors, upgrade regression errors, configuration error or hard drive error or failure. Partimage is fast and easy to use, create and image of the system partition often. When you have a problem, just restore the partition, and after a few minutes, you have the original partition. No need to reconfigure your system, utilities, daemons or reinstall and taylor applications. You can write the image to a CD-R for archival purposes or to avoid using hard-disk space.
  • Installing many identical computer images. For example, if you buy 50 PCs, with the same hardware, and want to install the same system on all of then, you will save a lot of time. Install on the first PC and create an image from it. For the 49 others, you can use the image file and Partition Image restore function.
  • An other example is for instructional use where all students need to have the same environment to start with. At the end of a session each student can write a CD ( or save their system partition to a fileserver, students frequently forget or misplace this tyoe of thing) with their current revisions. At the beginning of the next session, restore the image and they can continue. They may misconfigure or corrupt their environment in the course of their learning they will be able to "step back" to a well defined point where their environment was working.

Limitations

Partimage does not support ext4 or btrfs filesystems.

No defragmentation is performed during save or restore.

Filesystem being backedup must be unmounted and inaccessible to other programs. This means that when backing up the "system" filesystem, the operating system is down.

Single files or directories cannot be restored. Although the backup could be restored to an temporary/alternate partition and single files or directories could be recovered from the alternate partition.

Advantages

Fast. Since file fragments are not "hunted down" head movement is minimized allowing optimal use of the disk's cache.

Fast. Since only allocation clusters which are in use as read and saved.

Read only. None of the data being backed up is modified. This includes meta-data like last-access date. Preserves integrity of source partition.

Multi file synchronization. If there are multiple files that make up a fileSet, no file in the set will be out of sync with the other files.

Destination flexibility. Backup media can be a file on another partition on the same disk, another local disk or a network attached file.

Fast Restore. Data is simply flowed onto the disk optimizing the disk cache and minimizing disk seek time.

Simple restore. There is only one media to restore. No decision regarding order of restoring multiple back media.

No recover of deleted files. Files that were deleted at the time of the backup are not on another media that needs to be restored causing deleted files be resurrected

"Accounting is unaffected".

recovery to alternate partition Excellent choice for mirroring the file system on another disk or at another location.

Other information

For a utility for backing up a filesystem on a file basis with more features ( file exclusion, checksumming, multi-thread compression, encryption) See FSArchiver.

Forums: You should use Forums for any questions.

Project Status

License GPL 2 (GNU General Public License)
Stable version: 0.6.8
Testing version: 0.6.9_beta5
Authors: Francois Dupoux and Franck Ladurelle
Contact: Contact us (the email address is protected by an anti-spam system)
Operating System Linux 2.2/2.4/2.6
Architectures Intel i386+ and PowerPC

Several projects provide advanced boot/root disk and bootable CD to use partition image from a rescue disk: We recommend using the SystemRescueCd Homepage since it is maintained by members of the partimage team.

Go there...
http://www.partimage.org/Main_Page

Don

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