Time Machine - Storage

[oo7ml]

Hi, where does Time Machine store it's files. Am i right in saying there is a copy on the local disk and then a back up on the designated external drive.

I understand that when i plug my external drive in, Time Machine copies files to it BUT

01 - does Time Machine have some sort of other copy / back up of my files on my local machine too... for instance, if i do not have my external drive plugged in and i want to re-call a deleted file from last week, i can do this through Time Machine... so where is it getting the file from, as it cannot locate it from my external drive...

02 - how do the backups differ between what is copied to my external drive and what TM accesses on my local disk when retrieving a previous file... are both backups the exact same and are the files transferred to my external drive just an update of the local backup copy...

03 - if the system keeps a backup of all of the files on the local disk... how does it not eat up my hard drive...

Thanks in advance to anyone who can explain any of the above as i am completely confused

 

[maflynn]

Hi, where does Time Machine store it's files. Am i right in saying there is a copy on the local disk and then a back up on the designated external drive.

I understand that when i plug my external drive in, Time Machine copies files to it BUT

if you have a laptop, then Time Machine does store some of the backups locally but it also uses the external disk. Its part of the delta backups so instead of being completely on the external drive, its on your local drive, which imo is not ideal.

I personally disable this, by way of a terminal command.

 

[oo7ml]

Hi, thanks for your reply... if it is disabled locally... I presume that the external drive will need to be plugged in in order to retrieve a previous file

 

[maflynn]

Once its disabled, I'd recommend a backup to ensure everything is on the external drive, but yes you are correct you will need to ensure that the external drive is accessible by the Mac

The terminal command to disable is:
sudo tmutil disablelocal

 

[oo7ml]

Cool, thanks a million...