Retention on Backups - Full deleted, incremental stay?


#1

Hello,
after using urbackup for a while now I noticed some weird behaviour with the retention.

Lets say I have a client with lots of backups, like this:

  1. inc
  2. inc
  3. full
  4. inc
  5. inc
  6. full
  7. inc
  8. inc
  9. full

Now as time passes by, the oldest one, number 9, will be deleted in the nightly job. But that leaves me with number 7 and 8, two incrementel fullbackups without a corresponding full.
Are those 2 incrementals still functional, so do they still keep the whole content?

Thanks.


#2

UrBackup is designed to be very efficient and to make each backup look like a full backup when it comes to restoring files. The “bits” of the backed-up files are stored separately from the metadata, descriptive information about a file as shown in a directory listing. If one file is stored in two places, even on different machines, UrBackup will keep one copy of the file and use features built into the operating system to give you a view as if each backup had a full copy of the files in their proper locations.

Full backups here mean the Client program tells the Server program about every file on the client computer. Incremental means the Client checks the list it made from the last full backup and only tells the Server about files that have changed. In either case only files that don’t already exist on the server computer are transferred in full. The changes to the metadata are all that’s needed otherwise. Incremental backups tend to run faster so many admins set their systems up to run mostly incrementals and very few fulls.

tl;dr - For file restore purposes there is no difference inside UrBackup between ‘full’ and ‘incremental’ backups. Both contain the full file data as of the time of the backup.