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External hard drive play

I have always backed up my iMacs. My current drive is full, and so is that iMac. I want to begin trashing old files, to clear iMac space, but I don't want to accidentally erase items on the drive.

If I disconnect the drive, can I assume that the files remain intact? I hope this is a dumb question, but just making sure. I have never had to back up the Mac, or ever used the drives.

Thank you


PS. Imac OS is Yosemite

iMac

Posted on Dec 23, 2022 3:10 PM

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Posted on Dec 24, 2022 12:00 AM

I don't know what a 'boot drive' is.

A "boot drive", also known as a "startup disk", is the drive that contains macOS, the Mac operating system.

I want to know if I unplug the backup drive (TM) will the files remain on the backup drive when I delete files from the iMac in order to create more space on the iMac. I am no longer interested in backing up any more files on this iMac. All the files should already be on the backup drive.

You should not rely on Time Machine as a way to archive or store files, that's not its purpose. Time Machine backs up the contents of your computer, and it will delete old backups (and the files no longer on your computer) as needed.


What may work best for you is to either store large files on a separate external hard disk drive, or if your "older" iMac is new enough, you may be able to store all your files in iCloud and use iCloud optimization, which it sounds like you may already be doing for some files?


To proceed with the best advice possible, can you please let us know what is the exact year of your older iMac? You can find this information from the Apple menu  (top left) > About This Mac.


Jack

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Question marked as Top-ranking reply

Dec 24, 2022 12:00 AM in response to Tom Cray

I don't know what a 'boot drive' is.

A "boot drive", also known as a "startup disk", is the drive that contains macOS, the Mac operating system.

I want to know if I unplug the backup drive (TM) will the files remain on the backup drive when I delete files from the iMac in order to create more space on the iMac. I am no longer interested in backing up any more files on this iMac. All the files should already be on the backup drive.

You should not rely on Time Machine as a way to archive or store files, that's not its purpose. Time Machine backs up the contents of your computer, and it will delete old backups (and the files no longer on your computer) as needed.


What may work best for you is to either store large files on a separate external hard disk drive, or if your "older" iMac is new enough, you may be able to store all your files in iCloud and use iCloud optimization, which it sounds like you may already be doing for some files?


To proceed with the best advice possible, can you please let us know what is the exact year of your older iMac? You can find this information from the Apple menu  (top left) > About This Mac.


Jack

Dec 23, 2022 3:36 PM in response to Tom Cray

How much free space do you have on your boot drive? If there's not enough for a local snapshot Time Machine will indicate insufficient space (but not say where) and refuse to backup.


Therefore, free up about 50 GB of space (more if possible - I like to keep 100 GB free for optimal system and application performance) and try to run TM again.


The files that you have control over are located in the Documents, Downloads, Pictures, Music and Movies folders.  You can use this free app, GrandPerspective, to find the largest files on your drive so you can determine if they can be deleted or moved to an external HD for storage.


Note: you can empty the Downloads folder after the apps and/or updates that were downloaded have been installed or applied.  Some users have found a couple of Gigabytes of files in their Downloads folder which are no longer needed. 


Dec 23, 2022 11:05 PM in response to Old Toad

Thank you. I don't know what a 'boot drive' is. I will try to be very literal to avoid confusion. My iMac has no free space, of one TB. My backup hard drive is a mobile size drive, and has some space but not a lot. It is two TBs. My iMac can no longer do anything, but does not seem to be crashed, just full. I get the message on the iMac that says this (that it is full), and requests that I trash some items to free up space. Your answer looks like you think my backup is full and will no longer back up anything.


However, that is not my concern. I want to know if I unplug the backup drive (TM) will the files remain on the backup drive when I delete files from the iMac in order to create more space on the iMac. I am no longer interested in backing up any more files on this iMac. All the files should already be on the backup drive.


I want the old iMac (OS Yosemite) to work for a few items that I liked. iTunes is one of these. I think the answer is 'of course'. But I have never actually done anything with a full backup drive when I change to a newer iMac except put it back in the box and keep it. I do have a newer iMac, and many of the files in iCloud from the older iMac can not open in Monterey. So I want to continue using the old iMac with what it already has.



Dec 24, 2022 10:06 AM in response to Tom Cray

Tom Cray wrote:
1 - I don't know what a 'boot drive' is.

2 - My iMac has no free space, of one TB.

1 - Boot drive is then drive with the system and user data. It's normally the internal drive. In your case it would be the 1 TB drive.


2 - That means you don't have enough space for a "local" snapshot which is kept on the internal, boot drive. Therefore you need to move about 100 GB of files to an external drive so that your system and applications can function efficiently and get Time Machine to start backing up again.


When Time Machine needs additional space it will delete the oldest backup to make room for the newest backup.

External hard drive play

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