Incrementals, Differentials and Fulls

[JustTryinToGetI]

For example sake,

1st of month - Full backup

2nd-9th of month - Incrementals

10th of month - Differential

11th-19th - Incrementals

20 of month - Differential

21st - 29th - Incrementals

Okay....so my question is as follows. If I want to delete some B2D files to create free space, could I delete the Incrementals and differentials from the 2nd thru the 19th? And if I want to restore data from the  20th - 29th, do those restore jobs need any of the .bkf files from the 2nd thru the 19th?

[lmosla · Accepted solution]

Here is a similiar question/answer: https://www-secure.symantec.com/connect/forums/mixing-incremental-and-differential-backups

[pkh · Accepted solution]

You cannot delete something in the middle of the backup chain.  This will break the chain.  So, a short answer to your question is NO.

Unless you have a VERY good reason, do not mix differential and incremental backups.  See first part of my article below

https://www-secure.symantec.com/connect/articles/pros-and-cons-various-backup-schemes

The newer versions of BE makes it very hard for you to do so for very good reasons.  Also, for the newer versions of BE, you cannot delete part of a backup chain.

It is better to run more frequent full backups, rather than trying to use fancy backup schemes.  If space is a concern, then all the more reason to keep your backup chains short so that they can be deleted as soon as they expire.  You should not just worry about backups, restores are actually more important than backups.  If you cannot do a restore easily, then your backups are useless.

[JustTryinToGetI]

Thank you for your input. We will consider changing our backup scheme.   In the meantime, a follow-up question related to material.

Suppose there are 6 Incrementals in chronological order and a restore is needed.   Will the restore succeed if 1 of the Incrementals backups failed?

[pkh]

No.