Deleting specific data from a Time Machine backup held on an external drive

[MacInWin]

Well, I only have one V folder, V9, so I don't understand what you mean by "which?" It's in /Users/<<account>>/Library/Mail and it seems to hold all of my inboxes in that one location.

Yes TM somewhat backs up mail (but not the way it did before) and makes it much more difficult to restore individual folders or mail messages. Most users are not going to understand this and wind up losing mail.

I would debate the "somewhat" term. TM backs up Mail. Period. What is different is the restore process, and yes, it is more difficult that it used to be. But there is no reason, IMHO, for anyone to "wind up losing mail" because of how TM works.

I don't use any Google product, so I cannot address how Gmail works. I routinely purchased my mailboxes of spam and various notices/announcements/newsletters, etc, that I no longer need. I keep long term emails with account information in them (as well as storing the account information in my password holder), but try to keep it clean. I find it easy to sort by From: then select by the address the ones I don't want to keep. Then I sort by Subj: to get to emails I have sent to myself to keep track of various things I have automated (backups, for example) and want to know how they worked (or didn't). I get lazy and don't delete them right away, so I periodically purge them. Anyway, I don't ever recall needing to restore an individual email. Maybe I'm just fortunate that way.

 

[M915 Driver]

I agree. Either erase the drive using Disk Utility, or go into Recover mode, initiate Disk Utility, and erase that way.

How does one erase a time machine drive? I've been trying to erase my time machine drive for two days but the erase tab in disk utities has an "X" on it and it won't erase or format.

 

[MacInWin]

How does one erase a time machine drive? I've been trying to erase my time machine drive for two days but the erase tab in disk utities has an "X" on it and it won't erase or format.

You can try to turn off Time Machine (uncheck the "Back Up Automatically" in Time Machine Preferences). But I have always found I had to reformat the drive at the hardware level. That wipes everything off the drive, including whatever TM adds to mark the drive as a TM drive. That requirement is one of the reasons I don't have anything on a TM drive but TM.

 

[IWT]

@M915 Driver

In case you are in any doubt, what Jake is saying is that you need to highlight the media and not the indents below - as in this screenshot: - WD My Passport etc



And then select Erase.

Ian

 

[jpdemers]

Why not apply FileVault to the TM backup - then delete the files you want to ditch? Anybody getting hold of the backup drive won't be able to recover anything, let alone the deleted files.

 

[hempomatic]

Wow, if Hillary was this careful deleting her emails, she'd probably still be President.

 

[eisenhr]

Forgive me as a mac-forums novice that has gotten lost in this thread but I am a computer systems engineer of many years. We can encrypt folders with AES-256-bit key which may possibly be vulnerable to Quantum computer decrypting in another decade or 3. Those files will be as secure as the location that you store the key. We can exclude folders from individual TM backup drives and back them up to a different drive or storage mechanism altogether.

 

[MacInWin]

Forgive me as a mac-forums novice that has gotten lost in this thread but I am a computer systems engineer of many years. We can encrypt folders with AES-256-bit key which may possibly be vulnerable to Quantum computer decrypting in another decade or 3. Those files will be as secure as the location that you store the key. We can exclude folders from individual TM backup drives and back them up to a different drive or storage mechanism altogether.

Welcome to the forum.

Yep, all of that is possible. But what the OP wanted to do was to reach into a TM backup that has already been made and delete certain files there but leave the rest of the backup intact. Trying to do that will, with 99% probability, break the integrity of the backup database and destroy the entire backup, forcing a new start. The problem is that the horse has left the barn in that the offending files are already in the backup. Had they been encrypted before the backup, or excluded from the backup in advance, it would be no problem, but it cannot be "fixed" after the fact. Of course, the OP can encrypt the drive on which the backup is made to protect the data, but removal is simply a no-go.

 

[daitch]

From my experience, mess with TM at your peril. If you don’t use another backup app, such as Carbon Copy Cloner, at least frequently copy important folders and files to a separate external drive (NOT the TM drive) and keep a bootable macOS installer on, say, a USB stick.

Please explain how and where to get a bootable macOS installer?

 

[mfpv]

Apple have some instructions here:

Create a bootable installer – Apple Support (UK)

Use an external drive or secondary volume as a startup disk from which to install macOS.

support.apple.com