[Leica] Upgrading to Snow Leopard

[hartzell at alerce.com (George Hartzell)]

Henning Wulff writes:
 > At 9:37 AM -0700 8/27/09, George Hartzell wrote:
 > >Henning Wulff writes:
 > >  > Hi Nathan,
 > >  >
 > >  > It's a good backup of your personal data, but not a good backup for
 > >  > this purpose.
 > >  >
 > >  > You should have a cloned backup, [...]
 > >
 > >Henning,
 > >
 > >You've asserted that a Time Machine backup isn't a good general
 > >purpose backup but you've never said why.
 > >
 > >So, why isn't it a good general purpose backup?
 > 
 > 
 > George, it's a good backup of data and programs, but in itself it is 
 > not bootable, and if you have trouble with your upgrade and your 
 > printer starts giving you problems with the new software it's 
 > possibly very hard and time consuming to get that all working. If you 
 > have a cloned backup you can boot up _anytime_ with your old system 
 > and configuration, and not miss a beat. This is of course mainly of 
 > importance if your computer is work critical. If you can afford to be 
 > without a computer for a week you can do all sorts of things.
 > 
 > If you only have Time Machine backups, you will spend many hours 
 > getting back a useable computer, although it will definitely work. 
 > You have to format a disk, install OSX and then use the restore 
 > function to copy the current Time Machine info back onto that disk. 
 > Many many hours; depending on the size and amount of info on your 
 > disk it could be a day or more.
 >
 > With a clone it's a matter of minutes. If you use Time Machine and 
 > have a fairly recent clone, it's a matter of using the cloned disk to 
 > start up and then (possibly) using Time Machine to bring that disk 
 > fully up to date. That's about as fast as it gets.
 > [...]

The ability to instantly boot and go could be a very important
advantage.  Sooner or later you're going to have to invest the time to
switch over onto a replacement disk, but it might be nice to delay it
until it's convenient.

I think that your description of using Time Machine to recover from a
dead drive isn't quite accurate and is a bit pessimistic.  You replace
the dead drive (either internally or just attach a external
usb/firewire drive), boot off of the OS X DVD, and tell it to restore
from the Time Machine backup.  You don't need to go through the steps
of installing OS X, and I think that it'll even take care of
formatting the disk for you.  How long it takes to copy all of the
data over does depend on how big your disks are.

You're right though, having a recent bootable backup is indeed handy.

Thanks for the details!

g.