===== Backup of a partition ===== 

==== Making ready my backup device ====

On 23.03.2015 I did a backup of partition /dev/sda1. 

The new ''WD'' disk was formatted with a windows file system that didn't supported big enough file 
so I formatted it in ''ext3'' 

<code bash> 
mkfs -t ext3 /dev/sdb1      # Build the file system on WD - 1 TB 
</code> 

==== Backup ==== 
Before performing the backup save the partition metadata 

<code bash>
sfdisk -d /dev/sda > ./sda.sfdisk    # backup  partitions metadata 
</code> 

This is a copy of ''./sda.sfdisk'' 

<file> 
# partition table of /dev/sda 
unit: sectors 

/dev/sda1 : start=       63, size=300431502, Id=83, bootable 
/dev/sda2 : start=300431565, size= 12145140, Id= 5 
/dev/sda3 : start=        0, size=        0, Id= 0 
/dev/sda4 : start=        0, size=        0, Id= 0 
/dev/sda5 : start=300431628, size= 12145077, Id=82


</file> 

To backup the partition I restarted the system using a [[http://www.zenlive.tuxfamily.org/|live-CD]] and then 
did a copy of the partition to a normal file 

<code bash> 
# change directory where your put the partition copy 
cp /dev/sda1 ./sda1-25.03.2015   # on other *nix use dd instead of cp 
</code> 

You can mount this partition image in loop mode 

<code bash> 
mount -o loop /media/disk/sda1-25.03.2015 /mnt 
</code> 

and browse ''/mnt'' like a normal file system. 


==== Restore ====
 
Then, if you need restore you partition give these commands 

<code bash> 
sfdisk /dev/sda < ./sda.sfdisk    # restore partitions metadata 
</code> 

<code bash> 
# change directory where your put the partition copy 
cp ./sda1-25.03.2015 /dev/sda1  # on other *nix use dd instead of cp 
</code> 

==== Links ==== 

 * Information on [[http://wiki.sabayonlinux.org/index.php?title=HOWTO:_Backup_and_Restore_your_partition_table|how to backup and restore the partition metadata.]] 

==== Copy on fly a whole disk ====

<code bash>
ddrescue -n /dev/sda /dev/sdb ddrescue-sda-sdb.log
</code>