Time Machine, keepin ext HDD off

[LeandrodaFL]

Im planing on using Time Machine, but I prefer to keep my hard drive off, and turn it on once a month in order to perform the whole system snapshot.

When I turn on my ext hard drive, will Time Machine create all hourly versions from a whole month, or simply create a new one complete snapshot?

 

[Cinematographer]

TimeMachine will only create backups when the HD is connected and running. If you do the backups the way you described, you will only get one snapshot and you won't see the strenght of TimeMachine. Because anything that was created on your computer during this month and then accidently deleted during this month will be lost forever.

 

[marc11]

If you have a laptop running Lion TM will create hourly back ups on your local HDD as space permits until you connect the external HDD. Not sure if this works on anything other than portables.

But I am wondering why you want to do this? If it is wear or power concerns, you can use an ext HDD that automatically sleeps. My WD ext HDD will sleep after a few minutes of Time Machine backing up and wake up again when TM calls on it for the hourly back up.

 

[meady100]

I do similar to what you describe actually. I just flick it on for a few minutes each morning, and while that sacrifices hourly backups (which only get stored for a day anyway) I'm more than happy with one a day and not having it sitting there running, or even sitting in standby. Not sure how it would work on a once a month basis though...

 

[LeandrodaFL]

If you do the backups the way you described, you will only get one snapshot and you won't see the strenght of TimeMachine.

If you have a laptop running Lion TM will create hourly back ups on your local HDD as space permits until you connect the external HDD. Not sure if this works on anything other than portables.

But I am wondering why you want to do this? If it is wear or power concerns, you can use an ext HDD that automatically sleeps. My WD ext HDD will sleep after a few minutes of Time Machine backing up and wake up again when TM calls on it for the hourly back up.

Thanksf or the replies, let me give further info

I already have an always on ext WD My passport, to wich my favorite backup software does continues backups. If my internal hard drive fails, I have an instant backup with all important files

However, I want to have a snapshot of the entire system ready too, in case I upgrade my internal hard drive for instance or if my girlfriend goes crazy and deletes everything. I give her reasons to do so..

So, I want to have something that is turned off, and that I can manually choose when the backup happens. Honestly, I never delete anything accidentally.

 

[marc11]

Thanksf or the replies, let me give further info

I already have an always on ext WD My passport, to wich my favorite backup software does continues backups. If my internal hard drive fails, I have an instant backup with all important files

However, I want to have a snapshot of the entire system ready too, in case I upgrade my internal hard drive for instance or if my girlfriend goes crazy and deletes everything. I give her reasons to do so..

So, I want to have something that is turned off, and that I can manually choose when the backup happens. Honestly, I never delete anything accidentally.

Ah, so what I do is that I have a large external HDD which is a mirror raid, with three partitions, one is for Time Machine, one is a clone of my boot drive (internal SSD) and the third is a clone of my data drive (internal HDD).

I keep this drive connected to my AEBS and let Time Machine back up as normal. Then I use CCC's scheduler to clone the changes of my boot and data drives to the respective partitions once a month. So if either of my internal drives die, I have a clone of no more than 30 days old to boot from and I can use TM to restore any incremental changes.

The WD drive I use shuts itself down when not in use. Not sure if this will work for you as in many cases people want to store the clones off site or on seperate drives, and I do have a clone off site as well as all sorts of stuff backed up to DropBox, but my theory is that the chances of the internal drive and the external drive pooping the bed at the same time are low and with the raid, I am mirrored anyway, so three drives would have to fail at once.

So my only high risk factors are theft and home disasters. Real concerns, but since I keep another, although older clone off site, in addition to my DropBox back ups, I am pretty comfortable with this.