RI or I

[kspare]

Here the scenario.

Customer has 80 vms'.

They want to keep 28 days on local disk.
do a backup copy to an offsite location over a 300mb link, and keep 7 days there.
Weekly do a backup to tape (saturdays) and take those tapes offsite.

I can't find a clear answer so here is my question.

Do we:

1. Run Reverse Incremental
2. Incremental
3. Incremental with a synthetic full created on friday.
4. Incremental with Synthetic Full and Transform previous backup chains?

We are looking for performance and minimum disk space as the customer may obtain another company and add more vm's.

[HannesK]

Hello,
there is no clear answer to that question as every mode has pros and cons

Foreword: ignore everything I write if you plan to use REFS.

Lets start with the easy ones:
3. takes more space -> no go
4. (transforms) requires very much IO and should not be used in general anymore.

Reverse incremental vs. Forever Forward incremental: usually 2 is a little bit faster (depends on how many things run in parallel). VMware snapshots are open for shorter time. So 2 would be usually the preferred mode. For tape out option 1 (RI) is usually faster as the virtual synthetic full does not need to be created.

So I would tend to reverse incremental because of tape but forever incremental is also fine.

Best regards,
Hannes