Backup and Restore of LINUX System Disk using "dd" command:
Backup and Restore of LINUX System Disk using "dd" command:
creating disk1:
# dd if=/dev/zero of=disk1 bs=1024000 count=2048
# mkdir d1
# mkfs.ext3 disk1
# mount disk1 d1 // It will end with error, so try,
# mount -o loop disk1 d1
creating disk2:
# dd if=/dev/zero of=disk2 bs=1024000 count=2048
#mkfs.ext3 disk2
# mkdir d2
# mount -o loop disk2 d2
# df -h ----- result will be,
We can also use conv=notrunc,noerror options with "dd" command ,
-
The notrunc conversion option means do not truncate the output file —
that is, if the output file already exists, just replace the specified
bytes and leave the rest of the output file alone.
- Noerror means to keep going if there is an error. Dd normally terminates on any I/O error.
to confirm this,
# losetup -a
/dev/loop0: [fd00]:142387 (/root/disk1)
/dev/loop1: [fd00]:142390 (/root/disk2)
copy some file into d1 for example:
# wget http://ipv4.download. thinkbroadband.com/512MB.zip
shows like:
# ll /root/d1
total 541048
-rw-r--r-- 1 root root 16589672 Dec 23 22:14 1GB.zip
-rw-r--r-- 1 root root 536870912 May 30 2008 512MB.zip
drwxr-xr-x. 69 root root 4096 Dec 23 22:06 etc
drwx------ 2 root root 16384 Dec 23 21:58 lost+found
Making image for /root/disk1:
Now it creates the image of /root/disk1.
[root@ranjith ~]# dd if=/root/disk1 of=~/d1backup.img
dd: writing to `/root/d1backup.img': No space left on device
3562841+0 records in
3562840+0 records out
1824174080 bytes (1.8 GB) copied, 47.1943 s, 38.7 MB/s
# pwd
/root/d2
# ls
lost+found
Restore the image on another partition:
# dd if=d1backup.img of=/root/disk2
3562840+0 records in
3562840+0 records out
1824174080 bytes (1.8 GB) copied, 46.6134 s, 39.1 MB/s
The above command will restore the image (d1backup.img) of /root/disk1 to /root/disk2.
# ll /root/d2
total 541048
-rw-r--r-- 1 root root 16589672 Dec 23 22:14 1GB.zip
-rw-r--r-- 1 root root 536870912 May 30 2008 512MB.zip
drwxr-xr-x. 69 root root 4096 Dec 23 22:06 etc
drwx------ 2 root root 16384 Dec 23 22:05 lost+found
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