Backup with dd?

[Eric F Crist]

On Jan 3, 2005, at 12:46 PM, Andrew P. wrote:

> Eric F Crist wrote:
>> On Jan 3, 2005, at 12:15 PM, Henry Miller wrote:
>>>
>>> This might work, but it isn't best.   I can think of the following
>>> objections:
>>>
>>> You have no protection at all while the copy is in progress.  You 
>>> have
>>> overwritten part of the old backup, but not enough to be consistent.
>>>
>>> You have made no provision for data loss because of anything other 
>>> than
>>> a failing drive.   If your house burns down you can't get your data.
>>> (not strictly true, you can recover accidently deleted files so long 
>>> as
>>> you do the undelete before the next time you do the backup)
>>>
>>> FreeBSD has a few different RAID options.   With the right setup you
>>> can achieve disk reliability, and not have to switch cables on 
>>> reboot.
>> You seem to be under the impression that I'm doing this for the sole 
>> reason of a disk crash.  I'm actually doing it for more than just 
>> that reason.  For example, if my system gets hacked, most hackers 
>> will probably not care about an unmounted hard drive, and screw with 
>> the current mounted partitions.  Also, these drives wouldn't really 
>> be at the same point of this hypothetical drive failure, since one 
>> hard drive will only be used roughly once a week, while the other is 
>> in a constant state of use.  Most of my user-data is destined for a 
>> RAID-5 array that's roughly 1.2TB, so that's got it's own backup.  
>> This is simply for use in an emergency, so I don't HAVE to rebuild.  
>> Quite frankly, I don't have time to sit here and rebuild this system 
>> again any time soon.  This configuration I'm trying is ideal, with 
>> minimal interference.  I'm going to be installing removable drive 
>> bays so that my roommate is able to simple swap drive positions and 
>> reboot the system (it's headless, and he's not very tech savvy in 
>> this regard).
>
> Backing up with dd is ultimately straightforward, but is not a good
> idea at all. The matter is when dd is running, the source may be
> modified and the copy might be inconsistent. Software RAID should be
> the best option for your task: you can mirror a drive to a second one
> and then just plug the second one out of your computer.
>
> Best wishes,
> Andrew P.

Is this vinum?  Fairly difficult to setup, or is it straight-forward?  
Before I delve into that, any setup recommendations?

Thanks.
_______________________________________________________
Eric F Crist                  "I am so smart, S.M.R.T!"
Secure Computing Networks              -Homer J Simpson
-------------- next part --------------
A non-text attachment was scrubbed...
Name: PGP.sig
Type: application/pgp-signature
Size: 194 bytes
Desc: This is a digitally signed message part
Url : http://lists.freebsd.org/pipermail/freebsd-questions/attachments/20050103/64874409/PGP.bin