Topic: Why does the backup need twice it's size [Explained]

[girkers]

Could someone explain to me why when I do a backup to USB the system needs twice the size of the backup space available. My server says that the data to be backed up will be approximately 500GB, that means my USB HDD needs to have 1TB available for the backup to work. Thus if I increase my data on my server to 1TB in the near future I would need 2TB free for the backup to work. Why is this so?

Thanks

Girkers

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[janet]

girkers

Please read available documentation
http://wiki.contribs.org/Backup_with_dar#Backup_disk_size_limits_workaround

In short the backup is saved to the tmp folder on the backup media before the prior old backup is deleted. This is to ensure the new backup successfully completes, and you therefore have a good clean backup. The workaround suggests deleting the old prior backup before the new backup starts.

[girkers]

Thanks for that explanation mary, now it makes sense. I had ordered new backup drives this morning to ensure that I can do a full backup when I require, but with your explanation I know the reason why.

Thanks again.

Garth