HD full. What data is safe to erase?

For a scedualled BU i'm using an external HD. First BU made was a full BU, next 3 BU's where incremental.
For the next incremental BU i need more space on the HD.

Question: is it safe to erase previous incremental BU's, like incremental BU 1 and 2?

 

Hi Broosha,

you need the full trail from any chosen incremental back to the full. What you are talking about would work for differential, but not for incremental.

Assuming you have not already opted to compress your image files, perhaps you could look at adding compression to your filesystem on that harddisk.

You have a simple choice, assuming you want to do another backup. Either get a bigger disk, archive your existing data away (say) to DVD to free up space, or throw away your existing backups (Ouch).

F.

 

Dear Foghorne,

Thx for the fast reply on this. Since i'm using incremental its not an option to delete 1 or more previous incremental BU's. Correct?

But if i'm reading between the lines correctaly, i could have done this when i had used differential BU's.
So is it smart to use differential instead? What are the "minors" on this? If only plusses, then i can think of doing a complete BU again and build a tree again with differential.

With regards,

Broosha

 

Correct

I am not a user of differentials, as they have only appeared recently (V9 I think) but I understand they use more space than incrementals - perhaps someone in the know can comment.

Regarding your comment about a "tree"; again I understand that a differential can only be made against a full backup - so you would never have a dependent list like you do with an incremental. Just lots of differentials each one pointing back to the full, but independent of each other.

F.

 

“ … I understand they use more space than incrementals … “

Because of their nature, each new differential will more than likely grow in size since each one contains all the changes since the full – even those stored in the previous one.

“ … but independent of each other.”

Except when it comes to validating. Due to a known issue, you can only validate a DIFF if all the previous ones are available.