Time Machine local snapshots

I am running Mojave 10.14.3 on My Macbook Pro (13inch, Mid 2012).

I am having some issues with how Time Machine handles local snapshots.

Time machine does all the things I expect including creating local snapshots.

Using SUDO I can turn local snapshots on and off. I can also delete local snapshots and they disappear from my hard drive.

When my onboard storage get near it's limit Time Machine (TM) deletes the oldest local snapshot (just as Apple support says it will).

My issue is that when TM deletes the files it only deletes them to trash. It then takes me hours to empty the trash folder as my backups contain around 393,000 files.

Does anyone know of a faster way of permanently deleting these files from trash (or show me a way of ensuring that Time Machine deletes them permanently instead of sending them to trash).

Welcome to the forum.

You can always turn TM off by unchecking the "Back Up Automatically" box in preferences, that will stop snapshots at all.

Snapshots will be deleted (and erased) when a backup is made, so another potential is to keep the backup drive attached so that instead of snapshots, you get backups. But you said that TM is putting the snapshots in the trash, which it should not do. Are you using anything like Carbon Copy Cloner, or Super Duper? I ask because they, too, create snapshots.

You can also use something like Time Machine Editor or Time Machine Scheduler to schedule backups on a longer interval than one hour, and connect the backup drive for that schedule. That can be used to reduce the frequency of snapshots.

As for getting rid of them from the Trash, you can set the Trash to be deleted immediately, but that applies to ALL of the trash, which you may or may not want.

Frankly, the easiest is to just leave the backup drive attached and let TM do what it does, make backups, and avoid snapshots altogether unless you travel.

MacInWin said:

Welcome to the forum.

You can always turn TM off by unchecking the "Back Up Automatically" box in preferences, that will stop snapshots at all.

Snapshots will be deleted (and erased) when a backup is made, so another potential is to keep the backup drive attached so that instead of snapshots, you get backups. But you said that TM is putting the snapshots in the trash, which it should not do. Are you using anything like Carbon Copy Cloner, or Super Duper? I ask because they, too, create snapshots.

You can also use something like Time Machine Editor or Time Machine Scheduler to schedule backups on a longer interval than one hour, and connect the backup drive for that schedule. That can be used to reduce the frequency of snapshots.

As for getting rid of them from the Trash, you can set the Trash to be deleted immediately, but that applies to ALL of the trash, which you may or may not want.

Frankly, the easiest is to just leave the backup drive attached and let TM do what it does, make backups, and avoid snapshots altogether unless you travel.

Click to expand...

Thanks for your enlightenment, that now makes more sense.

I was getting snapshots (incremental) and backups (full) mixed up (how dumb).

However, at the end of the day, some process is loading old, complete backups into trash.

To me it now it looks like, as my external backup drive gets near full, TM strips out the oldest files and gets rid of them. They must be heading to trash.

It's that process that I want to curtail i.e. I want new backups to continue as normal and when TM is cleaning up I want TM to permanently delete the unwanted backup files instead of moving them to trash.

It's supposed to do that, so I'm confused why it's not. The way TM works is that the first backup is full, then after that only those things which have changed since the last backup are actually copied over to the backup. Anything NOT changed is linked to in the dated backup. That technique means that an external drive can last a very long time, in most cases. When TM needs more room, it deletes the oldest backup, but it still keeps the oldest "real" file it can. And none of them are supposed to go to the Trash, they just get deleted by TM from the drive.

Now, when a backup is deleted, it is true that all of the links in that backup would need to be deleted as well, so the count of backups can be large. But they shouldn't end up in the Trash.

You said:

It's that process that I want to curtail i.e. I want new backups to continue as normal and when TM is cleaning up I want TM to permanently delete the unwanted backup files instead of moving them to trash.

Click to expand...

Can you elaborate on what you mean by "new backups?" Are you starting a brand new backup very frequently? As I said, only the FIRST backup is normally a full backup, the rest are incremental and very small. But if you are manually creating new backups, that is going to fill an external drive pretty quickly.

Also, as a general rule the backup drive should be roughly twice the size of the data on the internal drive. So if your internal has, let's say, 500GB of data, you should be using a 1TB drive at a minimum.

My internal drive is 250GB, my Backup external drive is 480GB.

There is a folder created every two weeks which looks like a full backup, these are the ones I call new backups. I can search those folders and find a replica of my filesystem (at the time of the backup). The folder names are in the format "2108-10-16-065515", with the exception of the newest folder which is called "latest".

The folders which turn up in my trash have the same format but are older.

@GZinn001

You can always turn TM off by unchecking the "Back Up Automatically" box in preferences, that will stop snapshots at all.

Click to expand...

That's the only way. (Turning off TM completely) If you're running High Sierra or Mojave and your hard drive is formatted to APFS, you can not stop Local Snapshots from being stored on your hard drive. You're going to get them even if you use the terminal command to turn them off. We have several threads regarding that. However, there is a terminal command to delete them without going thru the Trash.

chscag said:

@GZinn001



That's the only way. (Turning off TM completely) If you're running High Sierra or Mojave and your hard drive is formatted to APFS, you can not stop Local Snapshots from being stored on your hard drive. You're going to get them even if you use the terminal command to turn them off. We have several threads regarding that. However, there is a terminal command to delete them without going thru the Trash.

Click to expand...

And that's exactly what I do as well. Up until macOS High Sierra, I left my Time Machine External Hard Drive permanently attached and backing up automatically (stop and leave approach).

However, since macOS High Sierra, I still leave my TM permanently mounted; but disabled "Backup Automatically" (System Preferences > Time Machine > Uncheck "Backup Automatically).

I then Click on TM on the Top Menu Bar on my iMac and from the Drop Down Menu, choose "Back Up Now". I do this about 3 times a day and/or if I have finished a particularly complex task.

Doing it this way, I never have more than two Snapshots on my iMac (Two because I have two TM backups attached and they are backed up to on an alternate basis).

Of course, I also have Cloned Backups as well - with the Snapshot option turned off.

Ian

What I am doing is using Time Machine Editor to set my backups for twice daily, leave the backup drive attached unless I'm traveling. I never have more than one snapshot, usually one taken right as TME fires up Time Machine to make a backup. If all you want is a backup every week or so, turn off TM by the unchecking of the "Back Up Automatically" box and invoke TM from the top menu bar or Dock when you want to make a backup. That will stop the snapshots. You will lose all of the interim changes between backups using that method and any file that is created and deleted between backups won't be saved either. But yo won't have snapshots every hour.

@OP:

If you're using Carbon Copy Cloner to make backups, leave the Safety Net on as that serves basically the same purpose as Time Machine. I have used the Safety Net feature to recover files that I had deleted but later on changed my mind and decided I needed them.