Time Machine are mulitple backups possible?

Hello o:

I do not know.

However, let me suggest a different approach that many use (me too). I use TM and also make periodic bootable clones using a little program called SuperDuper ($28 at www.shirt-pocket.com). In that way, I have two different backups. I probably should move to another external HD so that each backup is on a separate drive - something I have been putting off.

I am paranoid about backups myself. That is a good trait, IMHO.

Barry

oxygen_pro wrote:

I currently have a minimac using timemachine backing up to an external hard drive but getting abit paranoid I may lose all work if something happens to that external hard drive eg. gets stolen, is it possible to have two external hard drives running time machine at the same time?

No, not at the same time, but you can swap back and forth between two fairly easily, by just changing disks via TM Preferences. Some folks have two portable externals for this; they use one for a week or so, then take it to their safe deposit box or other secure offsite location and swap with the other one.

But as Barry says, using a separate type of app, particularly a clone, has a number of advantages. And yes, putting it on a separate drive is much safer -- all hard drives fail, sooner or later. And you might consider CarbonCopyCloner, the other popular clone-maker, as well (that's the one I use, in addition to TM).

I'm also interested in the answer to your original question!

An idea: You could use a RAID 1 external drive with 2 x 1GB hard discs
for example Western Digital 2TB My Book World Edition II Raid
( http://www.dabs.com/products/western-digital-2tb-my-book-world-edition-ii--raid- 5GTW.html?q=Western%20Digital%20My%20Book)
to get two backups on two independent discs.
Doubled safety but if it gets stolen, you would lose both.

That's a NAS server. It comes with it's own backup system, which might back up your system, but it most likely will NOT work with Time Machine: http://docs.info.apple.com/article.html?path=Mac/10.6/en/15139.html

It had been recommended to me for the use with Time Machine!
(Of course you wouldn't need the included special WD backup software.)

make periodic bootable clones using a little program called SuperDuper

Do you mean you always duplicate entire Time Machine backups?
If yes, then this is not a good solution for doing it every night.

@ Pondini: Can your CarbonCopyCloner also
only duplicate entire Time Machine backups?

coxorange wrote:
It had been recommended to me for the use with Time Machine!
(Of course you wouldn't need the included special WD backup software.)

Sorry, but Time Machine does not back up to network drives, except Time Capsules or a shared drive on another Mac running Leopard or Snow Leopard on the same local network. It will often back-up to a USB drive connected to an Airport Extreme, but even that is, technically, unsupported, and may require running a special Terminal command to make it work.

Here's the official word: http://support.apple.com/kb/HT1733 (Leopard) or http://docs.info.apple.com/article.html?path=Mac/10.6/en/15139.html (Snow Leopard).

You may find some hardware or "hacks" that might make it work, in some cases, to a degree. But use them at your own risk.

First, since this is *unsupported by Apple,* there's nowhere to go when there's trouble.

Second, you're risking a future update preventing it from working, and perhaps rendering your backups useless.

coxorange wrote:

make periodic bootable clones using a little program called SuperDuper

Do you mean you always duplicate entire Time Machine backups?
If yes, then this is not a good solution for doing it every night.

@ Pondini: Can your CarbonCopyCloner also
only duplicate entire Time Machine backups?

Sorry, but no, we're not talking about backing-up your backups. That's generally not a good idea; if there's a problem with the primary backup, it will be copied (and perhaps magnified) to the secondary copy.

CCC and SD are most commonly used to make full bootable "clones" of your internal HD, completely separate from and independent of your Time Machine backups. The advantage of them is, if your internal HD fails, you can boot up and run normally (if a bit slower) from the clone, unlike Time Machine. If something else breaks, though, like your logic board, you can't.

The disadvantage is, they usually don't keep "archive" copies of previous versions of things you've changed or deleted, like TM does. And they're much more CPU intensive, so it's rarely practical to run them more than once a day.

The idea is, having two separate, independent backups means if either app or drive fails, you still have the other. That's pretty rare, but does happen. There was a recent thread here where a full restore from TM backups was nearly done when BAM! the TM drive failed! (Murphy was an optimist!)

As I understand it, this WD drive can be used as a USB drive.
I think the RAID 1 thing works "internally".
Time Machine sees it as 1 USB backup drive.

I never wanted to use "hacks" or the like!!

coxorange wrote:
As I understand it, this WD drive can be used as a USB drive.
I think the RAID 1 thing works "internally".
Time Machine sees it as 1 USB backup drive.

I never wanted to use "hacks" or the like!!

According to the link you provided, under Features and Specifications, it's a NAS server with an internal RAID, connected via Ethernet (not USB).

There's probably a "hack" to make it look like a USB drive.

From a post in another forum (found by V.K.):

The technical reason why Apple limits Time Machine to 10.5 AFP volumes appears to be to prevent disk image corruption. There were additional features added to AFP in 10.5 to support Time Machine. These presumably allow the disk image engine to force disk image journal data to write out all the way to the disk. Without such features, a network interruption can result in a corrupted filesystem on the disk image despite journaling. Remember, journaling relies on the journal being written all the way to disk before the changes take place. If you can't guarantee that (e.g., because of network/NAS buffering) then the journal is useless. Time Machine appears to rely heavily on disk journaling to deal with network drop-outs, interrupted backups, and the like. Take this away and your data is at risk.

If the NAS you are using supports these features it should report them to the OS and you should natively be able to choose that volume. If you have to trick the OS to use the volume it means the NAS does not support it.

To summarize: if you care about your backup data you should avoid using non-natively supported AFP servers.

That post obviously applies to Leopard; Snow Leopard appears to have added some requirements, that are also not supported by all NAS devices, and some that were working with Leopard no longer work with Snow Leopard.

According to the link you provided, under Features and Specifications, it's a NAS server with an internal RAID, connected via Ethernet (not USB).

According to the link, under Expansion / Connectivity I also read
"Interfaces 1 x Hi-Speed USB - 4 PIN USB Type A..."

Here is another link:

http://www.lambda-tek.com/componentshop/index.pl?prodID=B128847&viewOverview=y&s howold=#productTop

It is nearly the same drive, but seems to have only USB.
Would this be good for Time Machine?

Another idea:

No, not at the same time, but you can swap back and forth
between two fairly easily, by just changing disks via TM Preferences.

Could this swapping be done each night
(first TM backup to drive 1, then swap and TM backup to drive 2, then swap back to drive 1),
so to get 2 Time Machine backups daily?

Another question:

We have three iMacs on one big table, all connected via Ethernet (Netgear ADSL router).
When I start Time Machine on iMac #1 it displays iMac #2's hard drive as possible
backup destination, but not the hard drive of iMac #3 (though they are identical new
iMacs and there is about the same free hard drive space available).
What could be the reason...?

If swapping would be possible - as described above - I would like to use iMacs #2 and #3
as destination drives.

coxorange wrote:

According to the link you provided, under Features and Specifications, it's a NAS server with an internal RAID, connected via Ethernet (not USB).

According to the link, under Expansion / Connectivity I also read
"Interfaces 1 x Hi-Speed USB - 4 PIN USB Type A..."

I believe that's a way to expand the NAS (by attaching a USB drive), not an alternate way to connect to your Mac. And it doesn't appear on their list of bootable drives: http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/stdadp.php?pfaqid=1787. I'd strongly recommend checking with WD before buying.

Here is another link:

http://www.lambda-tek.com/componentshop/index.pl?prodID=B128847&viewOverview=y&s howold=#productTop

It is nearly the same drive, but seems to have only USB.
Would this be good for Time Machine?

Looks like it would probably work. But it's still two copies of the same backup, in the same place.

That's better than only one, but much worse than two separate, independent copies, in two places, especially if you can take one off-site. That protects you against fire, flood, theft, direct lightning strike on your power lines, etc.