Time Machine question.

Hi Choctaw.
I'm like you: I don't have the need of 1 backup per hour. So after I do some important work on my iMac, I turn the external HDD on and TM is doing the backup within the hour. You can do that when you want : once a day, once a mounth or once a year

 

I have been using TimeMachineEditor for years and works perfect for me. I have it update timeMachine once a week, Monday mornings at 3:00 am while I am asleep. You can set it at any interval you like and still do an update any time you want if you are updating or adding new software.

 

It causes no harm to just let it run like it's designed. What exactly is your concern? Suppose you use your computer for a "not so important" task and a few hours later your HDD dies. Wouldn't it be nice to have that backup?

 

Pomeroy was referring to a separate piece of software called TimeMachineEditor (free). You need to download this first before you can customise the time settings like that. The standard settings without this little tool are pretty limited, yeah. Click the link in Pomercy's post and read the website's FAQ for more info. I use it myself, no complaints

 

Time Machine makes a complete backup of your system once. Every time it makes another it will only copy the files that have changed since your latest backup; i.e. it will record the differences. The shorter the interval, the quicker the backup. Sometimes it will only back up a few KB. Time Machine is sophisticated enough to know how your system looks at a specific point in time, even though you are not duplicating everything. It doesn’t matter if your drive is not available, because Time Machine will always attempt to just copy the difference between the last backup and now. This means that you can remove and connect your drive whenever you want. The idea behind hourly backups is that you can use the Time Machine app to restore individual files at exact moments in time. Moreover, you can manually exclude certain folders from backups in System Preferences. If you don’t want your documents backed up, just exclude the documents folder.

 

Yes, KALLT is correct. The hourly backups are nothing to be afraid of. They are almost all very small in size, correspondingly quick, and completely non-intrusive to anything else you are doing. Unless you happen to glance at the Time Machine icon you won't even realize when a backup is taking place.

Perhaps this will make you feel better: I've been using hourly TimeMachine backups on my iMac for 4 years now. I have about 67 GB of total storage used on my Mac main SSD. The total disk space used on my TimeMachine is now 107 GB (after 4 years of hourly backups). So there is really no downside to using it this way.

 

im not sure what you mean you turned it off.... i assume it's the same as 'unplug' it?

ok two things you should know.
1. if the 1-hour period is reached, system will attempt to mount the HD and back up once, if the HD is not found, certainly it will not back up. (though i'm not sure about local backup, back in mountain lion system will back up locally first and once your HD is attached it will move the backups to the HD. and you do have option to turn it off)
2. there are plenty apps to change the interval of backups. you can change it to whatever you like


edit, you should also understand how TM backup works.
'hourly' back up is not like you copy all your files over once an hour, after the initial backup, it will only copy whatever was changed/modified/added to the backup. so the size of backups will mostly be the same as 4-hour backups, with only slightly change.
so assume you modify three files (each 1mb) every hour. and during a 4-hour interval, you've changed files like
ABC (1st hour) DEF GAH(here you modified file A again) IJL
so if you do hourly backup, there will be four backups, and each backup will only contain the following files
1. ABC
2. DEF
3. GAH
4. IJL
so the size of backups will be 12mb (assuming each is 1mb)

if you do a 4-hour backup interval, there will be only ONE backup, and contains
1. ABCDEFGHIKL
the size will be 11mb, but you loose the first version of A


so there will be two situations.
1. you modify/reversion same files a lot.
then the difference of backup size will vary more depending on your interval, but i think i'd rather keep more versions right?
2. you don't reversion/modify existing files a lot
then if you increase your backup interval, it will not save you much disk space

 

Don't know if this will help:

http://pondini.org/TM/Works.html