Another Time Machine question, but....

Hi guys.
So I have finally got around to setting up an external drive to use as a Time Machine backup (yea, yea I know, took my time!)
Anyway, I have a question I haven't been able to find an answer too anywhere, so bow to the knowledge of those already using TM.

I am using it to back up my other 2 external drives as well, which contain music and movies respectively.
Now, if I delete a movie for example, will the next back up by Time Machine realise it's missing and just back up with it missing next time?
I know it just backs up files that have changed, so I assume it will, but I just wanted clarification.
Thanks.

(BTW, I got a 1.5TB Toshiba External in an Aluminum casing for £63 - bargain!)

I don't use it for external drives, but should be the same.

Time Machine makes back ups based on... time... or dates.

So,

If you open Time Machine to a date after the date you deleted the file, it will not be there.

If you then travel back to a date prior to the time you deleted the file, it will be there.

It gets a little easier to see once you have a couple of weeks/months worth of backups.

Thanks Bob, so I assume that after a set period it deletes the oldest back-ups, so that the drive doesn't fill up and become useless?

Kevriano said:

Thanks Bob, so I assume that after a set period it deletes the oldest back-ups, so that the drive doesn't fill up and become useless?

Click to expand...

As the drive becomes full, it deletes the oldest backups.

6string said:

As the drive becomes full, it deletes the oldest backups.

Click to expand...

Cool, but not until it's getting near full?
Can you manually delete older ones, or is there a setting to control how long it keeps them?
Sorry for the newb questions! Never used auto back up always done it manually.

When time machine is calculating the amount of changes since the last backup, it is also calculating how many older backups it is going to be writing over if the external HD is near full.

You can delete older ones, but you shouldn't, and if you do decide to, it takes forever.

Myself, every now and then when I am certain that I have everything in tact as I want it, I erase my time machine backup completely and start fresh.

I also keep a CarbonCopyCloner clone of my system.

What you can do, is partition your external HD.
ie, I have mine partitioned into 2 at the moment for the clones and the time machine backups, with a smaller partition for the clones, as it only has to be as my used HD space. Time machine partition being the larger partition.
I used to have 3 partitions, one for a bootable install disk, but for some reason when I reformatted the external last time, I decided to get rid of that one.

1.5TB is a lot of room to play with, but it still wouldn't hurt next time you come across a small cheap external, to get it just for what I would call extra security, to keep an upto date bootable clone that is separate from your 1.5TB in case one of the 2 fails at any stage.

Thanks 6String. Useful info.

Pleasure

I do the same thing as 6string. About once a year I delete my TM backup and start it over from scratch. Have never let it go long enough to start deleting the old stuff, so don't really know "how full" it has to be to start doing that.

My current TM backup of about 8 months is 428GB and only have 160GB in use on my Mac.
Pretty sure my wife's TM Backup has been running since Leopard came out and it's hitting close to a whopping 38GB in size now.

That bootable back up has saved my sanity a couple of times, especially after an upgrade install of Snow Leopard booted up to a kernel panic. Took about 10-15 minutes to boot back into Leopard, check the logs, figure out the offending kext that was incompatible with SL and move it.