Time machine problem

[mdijb]

I keep seeing this Screen trying to backup to Time machine.

However there is over 140g GB o space on he backup location for this backup but it is not happening.

How can I fix this issue

MDIJB

[Slobodan Blagojevic]

If I am not mistaken, Time Machine is supposed to automatically delete the oldest backup in order to make space for the latest one.

[BobShaw]

What does the rest of it say? It should say requires x but only y available.
Yes it will delete older backups but never the last one.
So it needs more than twice the space of what it is backing up.

[mdijb]

Before the above Time M chine message shown above appeared, there were several messages showing what you described--it did delete the oldest items.  Now however, only the message above appears and the backups are failing.

MDIJB

[mdijb]

Additional information

I ran Utilities-> Disc first aid on the drive use for the Time machine backup and no problems were found.

I also disconnected->reconnect--->no change in behavior

MDIJB

[BobShaw]

Open the Time Machine Preferences, either from the the backward clock icon at the top right or System Preferences Geared Wheel in the Dock (at the bottom unless you moved it)

Find the Drive that you are backing up to.
There will be a little Red "I". Click that. It will tell you why it failed. Likely it is full.

If that is the only disk then you "should" have more disks than one for backup, but one is better than none. Keep the one you have and ideally get a bigger one.

Also click Options down the bottom right of the preferences and see what it is backing up. Should be everything except the Backup disk itself.

Also just double click the disk on the desktop and you will see the backup and can navigate to the individual files if necessary.

[schertz]

What does the rest of it say? It should say requires x but only y available.
Yes it will delete older backups but never the last one.
So it needs more than twice the space of what it is backing up.

The bold part is not entirely true. Time machine will only backup the files that have changed since the last backup, so you need a bare minimum backup drive equivalent to 1x "Used" source disk space + space of any files that have changed. It does this by creating hard links for files that have not changed, so there are multiple folders/files organized by date, but they all point to the same "data" on the disk (until the source file is changed).

To mdijb: More information about your drive setup would be helpful, how many, total size and used space and any files / drives in the TM "excluded" list. It's possible TM is trying to backup more than you think (like another external drive you attached), but no-one can say without more info.

MS

[mdijb]

The last comment is what I discovered today.  THe Backup included all 4 drives in My mac, and that is a large amount of dat.  I added the drive to list of exclusions that I did not want backed up and it seems to be working now.

I think I will remove the prior backups and start over with a clean one to night.

MDIJB

[BobShaw]

THe Backup included all 4 drives in My mac, and that is a large amount of dat.  I added the drive to list of exclusions that I did not want backed up and it seems to be working now.
I think I will remove the prior backups and start over with a clean one to night.

Why would you not want to back up every drive? If that is the case then you may as well take them out and throw them away. If they are not changing then no additional space is going to be used backing them up. The thing that most people seem to miss with TimeMachine is that you can rebuild an entire computer to a new one exactly as it was. Data, Applications, Users, Settings. You can't do that with other systems.