Date: Wed, 09 Mar 2005 10:02:07 -0800 From: John Pettitt <jpp@cloudview.com> To: james.cook@utoronto.ca Cc: freebsd-questions@freebsd.org Subject: Re: Backup of hd using DD. Message-ID: <422F3A1F.7050803@cloudview.com> In-Reply-To: <20050309172646.GA19884@b210-12.cdf.toronto.edu> References: <20050309171330.4c1c2ede.thib@mi.is> <20050309172646.GA19884@b210-12.cdf.toronto.edu>
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james.cook@utoronto.ca wrote:
>On Wed, Mar 09, 2005 at 05:13:30PM +0000, Thordur I. Bjornsson wrote:
>
>
>>Hello list.
>>
>>I had an idea about using a tool similar to dd(1) take backup's of
>>entire disks.
>>
>>Here's my situation:
>>My father has an old PII running Win98 (Don't ask don't tell... he's
>>using very old financial software ;). Needless to say the thing keeps
>>getting borked and reinstall of his entire setup is quite frustrating.
>>
>>Now I was wondering if I could simply set the thing up with all the
>>programs that he needs + drivers + anti viral &c but minus the financial
>>software ofcourse and the rip the disk out of the machine put in my
>>workstation make an image of it and keep it safe and when the machine
>>goes borked I could simply rip the disk out again put it in my machine
>>and dd the image back onto the disk and restoring the "good-image" setup
>>(then I would restore his financial stuff with the most recent backup
>>(wich he keeps on a zip disk).
>>
>>Now my questions are:
>>1) When I dd the image back onto the disk:
>> What about the 'free' hd space ?
>> What about the bootloader for Win98 ?
>> The registry &c ... ?
>>
>>
>
>The bootloader, registry and all that are on the hard disk, so if you make an
>image of the whole thing it'll all be preserved. The only thing I can think
>of that you won't be backing up is your BIOS configuration, but that's
>probably OK.
>
>As for free space... if you've got an 80GB hard disk and you image the whole
>disk, you'll get an 80GB image, no matter how much free space was on it. If
>you want a more efficient way of doing things, I suppose you could put the
>"base system" on a separate small slice, and just backup that slice...
>but then you have to be careful to include the bootloader as well, which might
>not be stored inside any slice.
>
>
If you zero the disk before you do the initial install of Win 98 (dd
if=/dev/zero of=/dev/(disk to zero) then all the freespace will be zero
blocks which will compress really well.
>
>
>>2) How do I make an image of the entire disk using dd(1) ?
>> Or should I use some other software ?
>>
>>
>
>dd if=/dev/{disk to backup} of=/path/to/new/image/file
>
>where {disk to backup} is something like /dev/ad0 (for full disk) or
>/dev/ad0s1 for slice 1, and /path/to/new/image/file is where you want to put
>the image.
>
>Use the option "bs={some big number}" to dd to make it a faster (man dd for
>more info).
>
>
Make sure you use the raw disk device (/dev/adX) not a partition (/dev/adXsY) so that you get the bootloader.
John
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