Difference between revisions of "duplicate a hard drive using dump and restore"

Revision as of 14:45, 30 June 2014

This guide will show you how to duplicate a hard drive's running, mounted filesystems to another drive.

source drive = /dev/sda target drive = /dev/sdb

prep target drive

create the partitions and filesystems on the destination hard drive

from the restore man page...

Restore  (rebuild)  a  file  system. The target file system should be made pristine with mke2fs(8), mounted, and the user
             cd'd into the pristine file system before starting the restoration of the initial level 0 backup.

list source drive partion info

# fdisk -l /dev/sda

Disk /dev/sda: 64.0 GB, 64023257088 bytes, 125045424 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x77804419

  Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      133119       65536   83  Linux
/dev/sda2          133120    16910335     8388608   82  Linux swap / Solaris
/dev/sda3        16910336   121767935    52428800   83  Linux

duplicate the partition info above on the target drive

one limitation of using dump / restore is that the filesystem geometry must match between the source and the target drives. I use fdisk to do this. The steps aren't included here. When done your target drive partions should match the source above.

example:

# fdisk -l /dev/sdb

Disk /dev/sde: 80.0 GB, 80026361856 bytes, 156301488 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x01a8acb1

  Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048      133119       65536   83  Linux
/dev/sdb2          133120    16910335     8388608   82  Linux swap / Solaris
/dev/sdb3        16910336   121767935    52428800   83  Linux

create filesystems

#
# mkfs.ext3 /dev/sdb3
mke2fs 1.42.7 (21-Jan-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
1810432 inodes, 7228622 blocks
361431 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
221 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks: 
       32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
       4096000
Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

perform dump / restore

make temporary mount points

# mkdir /mnt/sdb1
# mkdir /mnt/sdb3

note: we are skipping the swap partition as there is no point in duplicating data there

dump first partition (in this example boot)

# mount /dev/sdb1 /mnt/sdb1
# cd /mnt/sdb1
# dump -0 -f - /boot | restore -r -f -
 DUMP: WARNING: no file `/etc/dumpdates'
 DUMP: Date of this level 0 dump: Tue Apr 29 15:45:03 2014
 DUMP: Dumping /dev/sda1 (/boot) to standard output
 DUMP: Label: none
 DUMP: Writing 10 Kilobyte records
 DUMP: mapping (Pass I) [regular files]
 DUMP: mapping (Pass II) [directories]
 DUMP: estimated 24536 blocks.
 DUMP: Volume 1 started with block 1 at: Tue Apr 29 15:45:03 2014
 DUMP: dumping (Pass III) [directories]
 DUMP: dumping (Pass IV) [regular files]
 DUMP: Volume 1 completed at: Tue Apr 29 15:45:03 2014
 DUMP: Volume 1 24580 blocks (24.00MB)
 DUMP: 24580 blocks (24.00MB)
 DUMP: finished in less than a second
 DUMP: Date of this level 0 dump: Tue Apr 29 15:45:03 2014
 DUMP: Date this dump completed:  Tue Apr 29 15:45:03 2014
 DUMP: Average transfer rate: 0 kB/s
 DUMP: DUMP IS DONE

look at my pretty files

# ls -1
System.map-genkernel-x86_64-3.10.17-gentoo
System.map-genkernel-x86_64-3.7.9-gentoo
boot
grub
initramfs
initramfs-genkernel-x86_64-3.10.17-gentoo
initramfs-genkernel-x86_64-3.7.9-gentoo
...

now for the good stuff, dumping a running root filesystem!

mount and cd to restore point on the target drive

# mount /dev/sdb3 /mnt/sdb3
# cd /mnt/sdb3

dump and restore files

# dump -0 -f - / | restore -r -f -
 DUMP: WARNING: no file `/etc/dumpdates'
 DUMP: Date of this level 0 dump: Tue Apr 29 15:45:46 2014
 DUMP: Dumping /dev/sda3 (/) to standard output
 DUMP: Label: none
 DUMP: Writing 10 Kilobyte records
 DUMP: mapping (Pass I) [regular files]
 DUMP: mapping (Pass II) [directories]
 DUMP: estimated 14965465 blocks.
 DUMP: Volume 1 started with block 1 at: Tue Apr 29 15:45:54 2014
 DUMP: dumping (Pass III) [directories]
 DUMP: dumping (Pass IV) [regular files]
 DUMP: 36.90% done at 18406 kB/s, finished in 0:08
 DUMP: 77.94% done at 19441 kB/s, finished in 0:02
 DUMP: 98.49% done at 16232 kB/s, finished in 0:00
 DUMP: Volume 1 completed at: Tue Apr 29 16:01:38 2014
 DUMP: Volume 1 14918960 blocks (14569.30MB)
 DUMP: Volume 1 took 0:15:44
 DUMP: Volume 1 transfer rate: 15803 kB/s
 DUMP: 14918960 blocks (14569.30MB)
 DUMP: finished in 944 seconds, throughput 15803 kBytes/sec
 DUMP: Date of this level 0 dump: Tue Apr 29 15:45:46 2014
 DUMP: Date this dump completed:  Tue Apr 29 16:01:38 2014
 DUMP: Average transfer rate: 15803 kB/s
 DUMP: DUMP IS DONE