Lend273 wrote:
Up until now I have been using Super Duper once a week to back up my macs.
Now that I have a new iMac and Snow Leopard I am thinking about using Time Machine.
Since you have an iMac, why not just connect the drive directly? It will be
much faster and more reliable.
I would probably want to do the nightly backup via wireless network utilizing my Apple Airport Extreme system.
That works for some, but it's "iffy" and +*not supported by Apple.+* See the
Using Time Machine with a USB drive connected to an Airport Extreme *User Tip,* also at the top of this forum.
How efficient would this be?
The first backup copies everything, of course. That would take, +*very roughly,+* about 18 hours via Ethernet, longer via WIFI, but there is a way to start it over the network, then finish via USB or F/W. USB would take perhaps 10 hours, F/W 400 maybe 8, F/W 800 about 5.
How reliable?
As noted in the link, it varies. While I learned long ago (the hard way, of course 😟 ) never to trust my backups to a single app or piece of hardware (no app is perfect; all hardware fails, sooner or later), that's even more important if you decide to do this. On occasion, your backups may come up corrupted. Sometimes Disk Utility can fix them, sometimes +Disk Warrior+ can, sometimes nothing can, and you have to erase and start over.
Thus I'd recommend
continuing to do SD backups, perhaps to a portable external HD you can take off-site, no matter how you do TM backups.
After the nitial backup, how long would the nightly backup take?
TM backups run hourly, not nightly, as long as your Mac is awake and the destination is availabe.
That depends mostly on how much you change between backups and how good your WIFI connection is. Unless I've added or changed something big, I rarely notice them, unless I happen to see the icon spinning. But if you add or change significant amounts of data, especially over the same WIFI connection, you'll see a slowdown.
You mentioned multiple Macs -- you can back other Macs up over your network to the same disk (preferably a different partition), or a different one, connected to your iMac. See #22 in the
Frequently Asked Questions *User Tip,* also at the top of this forum.
You might want to review this:
Time Machine Tutorial
and perhaps browse the rest of he
FAQ Tip.