Best procedure for full backup of live system

Michael David Crawford mdc at
Sat Oct 17 10:35:38 UTC 2009

Nerius Landys wrote:
>   > dd if=/dev/ad4 of=MBR_backup bs=512 count=1
> to back up the MBR, so I can recontruct the boot program and partition
> table.  But they don't mention that in the Handbook.

While that will back up the Master Boot Record, it's not sufficient for 
the general case of MS-DOS style partitions.  It will only include the 
primary and extended partitions.

The logical partitions, which exist inside an extended partition, are a 
linked list whose elements are distributed across your disk somewhere. 
If you have any extended partitions, you need to back them up too.  They 
aren't part of the 512-byte MBR so just using dd to grab the first 512 
bytes won't do.

The Linux sfdisk program can create a machine readible text file that 
includes any logical partitions.  Does FreeBSD also have sfdisk? 
Perhaps it's in ports.  I don't have my FreeBSD box handy right now so I 
can't just look.

... and as has been pointed out, you'll also want your BSD disklabel 
which is a whole different beast.

Michael David Crawford
mdc at - We Don't Assume You Are Stupid.

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