Time machine on unplugged drive

[HelterSkelter]

Hi there,

I own a couple of Mac laptops both of which I use on nights at home as personal computers and during the day as pro ones.

Is it possible to do Time Machines backups on a drive that is only accessible (should it be network or USB) at nights?

Meaning I let TM do its backups hourly on evenings and have it completely unaccessible during days?

How will TM handle this situation?
I know I will not have that fine a granularity in my backups, I just do not see myself taking my 4TB NAS to work everyday and having to move around meetings with an external USB drive is not conceivable either.

I heard it was possible to backup on a partition of the same drive that is being backed-up. But this is ridiculous for a drive as small as the 128 GB SSD of an MBA and it also is not very secure to protect against hardware drive failures.

So! is my use case feasible?

Thank you

Edit: sorry if posting in this Lion section is inappropriate, I just figured that the fact that it is under 10.7 could be any relevant.

 

[mrapplegate]

Hi there,

I own a couple of Mac laptops both of which I use on nights at home as personal computers and during the day as pro ones.

Is it possible to do Time Machines backups on a drive that is only accessible (should it be network or USB) at nights?

Meaning I let TM do its backups hourly on evenings and have it completely unaccessible during days?

How will TM handle this situation?
I know I will not have that fine a granularity in my backups, I just do not see myself taking my 4TB NAS to work everyday and having to move around meetings with an external USB drive is not conceivable either.

I heard it was possible to backup on a partition of the same drive that is being backed-up. But this is ridiculous for a drive as small as the 128 GB SSD of an MBA and it also is not very secure to protect against hardware drive failures.

So! is my use case feasible?

Thank you

Edit: sorry if posting in this Lion section is inappropriate, I just figured that the fact that it is under 10.7 could be any relevant.

I don't see a problem with just plugging in the NAS at night. What is the actual problem? During the day while at work your laptop won't be backed up. Since you're using Lion, you will have local snapshots enabled by default and it will store any changes to backup once connected back to the TM source. Here is info from the TM help file:

If you have a portable computer, in addition to saving backups on your backup disk, Time Machine saves hourly snapshots of files and stores the snapshots on your computer’s internal drive. If your backup disk isn’t connected, Time Machine continues saving snapshots on your internal drive, and then resumes backing up to your backup disk when you reconnect it.

 

[Contiguous]

Yeah, if Time Machine is on, once you plug in your drive at night, the backup should start automatically.

 

[HelterSkelter]

Ok good! happy to hear so!!

I was expecting it to work smoothly as long as the backup drive was available.
My only fear was what would it do once it would want to back up and the drive is not available and if it could resume the backing-up once it is back available.

Thanks for your answers.

 

[crypticlineage]

The beauty of time machine is, even if your samba/NAS share was not mounted (when at home), it will automatically mount it for backups and then unmount it again.

Of course this does not apply to external hard drives yet, because Apple still needs to work it's magic to plug the drive in automatically.