Time Machine: Back-up then delete originals?

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Unfortunately, that's not the philosophy used to design Time Machine backups.

In theory, your idea is good for a while if your Time Machine drive is gigantic (say 10 times the capacity of your current internal storage, 1TB per 100GB internal storage).

There is no guarantee that you'll be able to retrieve Time Machine backups 'forever', because when the Time Machine drive eventually gets full, it removes the OLDEST backups to free up additional space, and notifies you AFTER those backup files were erased.

Time Machine is mostly focused on having recent backups. It copies changed files to the Time Machine drive hourly for the last 24 hours, then grooms those backups daily, weekly, and monthly. Details supplied by Apple here > http://support.apple.com/kb/ht1427

So yesterday's spreadsheet and last week's report and last month's vacation photos will be there for quite a while, but six months, a year, two years, three years from now, as your Time Machine drive fills up and old files are deleted to make room for new files, there's no guarantee, especially if you are frequently adding/changing/deleting files from your internal drive.

You didn't ask, but paranoia about having enough backups and being able to access them when you NEED them comes from experience. If you want to be (relatively) certain that you can retrieve files you've removed from your current drive, I suggest a multi-step backup strategy.

1) Clone your entire current hard drive to another external hard drive of at least equal capacity on a regular basis (weekly, monthly, What's your time worth?); That gives you a bootable backup of the most recent stuff in case your primary drive fails. Then you can use Time Machine to quickly restore JUST the stuff you created since your last drive Cloning, instead of spending an entire day or more restoring a full Time Machine backup.

2) Use cloud storage from more than one vendor. iCloud and iTunes is great, but also use free accounts from other providers, so in case of a catastrophic event affecting an entire region, you're safer, because at least some of your storage will be in another location.

3) Burn DVD copies of priceless files such as family photos that can never be recreated by any means. Store them off-site, like a bank safe-deposit box. Keep a copy at work. Mail them to your relatives. Remember that technology keeps changing and today's DVD may be as useless as an 8-track tape or audio cassette in a few years, so keep up with the technology.

4) Copy your own critical WORK files to flash drives and carry them with you if permitted by your company.

3 or 4 (or 14) backups is still not an ABSOLUTE GUARANTEE that you'll always be able to retrieve a file later, but it's better than relying solely on Time Machine, and then discovering that the files were erased without warning.

Message was edited by: kostby

Hello kostby,

I'm not sure if you'll get this, but I have the same situation you were attempting to provide a solution to in your above post from 3 years ago. I'd like to safely back up data from my internal drive and be able to delete some apps and documents so that my machine is leaner but at a later date retrieve that content again but also keep the changes made since the last HD clone.

I understand steps 2, 3 and 4 in your strategy, but it's step 1 I'm not sure I understand. TO break it down, I don't follow how I could do the following without losing the content removed from the internal HD in step #2:

1. do a complete internal HD clone to backup drive #1
2. moving forward, add content - and delete content - on the internal HD
3. have those internal HD changes saved by Time Machine to backup drive #2
4. then do a new complete internal HD clone to the backup drive #1

Wouldn't I then have lost the content I deleted from the internal HD after the previous clone? I'm not sure if the key is in the restoring with Time Machine from backup drive #2 since the last clone... but I'm missing something. It seems to me you'll be able to save your internal HD additions moving forward, both in subsequent clone backups and also in the time machine backup, but you'll lose the content you deleted from the HD between clones.

kostby, if you see this, or someone else, and can shed light on how this strategy could allow you to safely remove content from the primary drive, but have that content besafe moving forward, that'd be a great help.

Thanks!

You might want to consider starting a new discussion. Since this one is a couple of years old, less people are likely to look at it. A new post would be much more visible. You can link to this one.

It seems to me you'll be able to save your internal HD additions moving forward, both in subsequent clone backups and also in the time machine backup, but you'll lose the content you deleted from the HD between clones.

You'll eventually lose the files.

Your best option is to copy the files to an external drive to save them. Time Machine may eventually delete them as will a clone.