I understand that time capsule will delete old backups when it needs space. Assume I have a file on my iMac that gets written to the initial backup. Assume that file never changes. Will that file always remain on the backup, or is it possible that the file could be deleted when time capsule needs more space.
iMac Line (2012 and Later)
I understand that time capsule will delete old backups when it needs space
If you are asking about Time Machine, that is the theory, but in practice, it does not work all that reliably.
For example, Time Machine will have a hard time if the Time Capsule or back up hard drive is full......and a new backup requires more than average amount of space. This happens all the time when a backup drive is full, and the user has upgraded to a new operating system or added a lot of new images or media to his/her Mac since the last backup.
Suddenly, Time Machine displays the dreaded message of "Time Machine cannot back up because there is not enough free space on the backup drive". Then, you are stuck having to figure out what to do.
Assume I have a file on my iMac that gets written to the initial backup. Assume that file never changes. Will that file always remain on the backup?
Yes, because Time Machine will always keep a current copy of your Mac in addition to a history of how your Mac looked at dates in the past. Since the file that you asked about never changed and was never deleted, it is still "current" on your Mac, so that file would not ever be deleted by Time Machine.
If Time Machine is behaving and the backup drive is full, and the Time Machine gods are happy, Time Machine will start to delete the oldest backups first, to make room for new backups. This usually works OK with small new "incremental" backups, but if the user has added a lot of new data on the Mac since the last backup, Time Machine is probably going to present a message that it cannot back up the Mac.
To avoid these issues, it is wise to begin a new backup to another backup drive before the current back up drive is full. Or, if you really don't need to be able to see how your Mac looked months ago, you can erase the backup drive and start over again with a new backup.
Our advice.........Do not rely on Time Machine to automatically delete old backups to make room for new backups.
Better advice.......have two backup plans. One using Time Machine and another using Carbon Copy Cloner, SuperDuper, or ChronoSync. Time Machine is the least reliable of these applications in my opinion and experience.
I understand that time capsule will delete old backups when it needs space
If you are asking about Time Machine, that is the theory, but in practice, it does not work all that reliably.
For example, Time Machine will have a hard time if the Time Capsule or back up hard drive is full......and a new backup requires more than average amount of space. This happens all the time when a backup drive is full, and the user has upgraded to a new operating system or added a lot of new images or media to his/her Mac since the last backup.
Suddenly, Time Machine displays the dreaded message of "Time Machine cannot back up because there is not enough free space on the backup drive". Then, you are stuck having to figure out what to do.
Assume I have a file on my iMac that gets written to the initial backup. Assume that file never changes. Will that file always remain on the backup?
Yes, because Time Machine will always keep a current copy of your Mac in addition to a history of how your Mac looked at dates in the past. Since the file that you asked about never changed and was never deleted, it is still "current" on your Mac, so that file would not ever be deleted by Time Machine.
If Time Machine is behaving and the backup drive is full, and the Time Machine gods are happy, Time Machine will start to delete the oldest backups first, to make room for new backups. This usually works OK with small new "incremental" backups, but if the user has added a lot of new data on the Mac since the last backup, Time Machine is probably going to present a message that it cannot back up the Mac.
To avoid these issues, it is wise to begin a new backup to another backup drive before the current back up drive is full. Or, if you really don't need to be able to see how your Mac looked months ago, you can erase the backup drive and start over again with a new backup.
Our advice.........Do not rely on Time Machine to automatically delete old backups to make room for new backups.
Better advice.......have two backup plans. One using Time Machine and another using Carbon Copy Cloner, SuperDuper, or ChronoSync. Time Machine is the least reliable of these applications in my opinion and experience.
The ability to delete old backups to make way for new backups went pear shaped when Apple started new OS revisions annually.. that causes enormous blowouts on the backup size and total confusion of what files are necessary to get things working.
It means you must control the backup and ensure it is archived off or some other practice is employed to ensure you have viable backups.
+1 with Bob on using a cloner.. as CCC for example as one of the best on a local disk can create a bootable clone of your drive.. with that you know in a few minutes that you have a viable backup.. just boot from it..
Then either archive the Time Capsule or erase the drive and start a fresh Time Machine backup if you wish.. but I am with Bob in using both.. and in fact I use CCC just once a day.. it is fast and has never let me down.. Time Machine is still on defaults and backs up to both internet and local target and fails regularly at least to the network target.. so I have learned it is too unreliable to depend on.. But it never bothers me now when it delivers its ultimate I have shat in my own nest and need to start all over again.
You just rinse, shampoo and repeat.. expect nothing good.. and whatever good happens is all bonus.
Thank you for the helpful advice . Carbon Copy Cloner it is!
What will time capsule delete in a backup?
