I think you answered this in another thread and understand how the retention works... If you run a full every 6 months and need to keep 1 year, then you'll have to run backups until there are 18 months in storage before the oldest backup set of 6 months can be removed, leaving you with 12 months in storage.

As you pointed out, if we detect an issue, we'll notify you, but any damage to a backup archive file in the chain could prevent any incremental backups after the missing or damaged file to be inaccessible. So there is more of a risk of data loss if you run into an issue. I won't get into cloud durability, as that's something you can research yourself. But I would say that for many customers, running a full backup every 6 months would not be frequent enough for them (or their customers in the case of managed services).

You can optionally limit deleted file exposure with the GFS Retention settings by keeping backups for a longer period of time.

Thanks for the clarification David.
We wanted to hear that experienced opinion before think this through.

You can optionally limit deleted file exposure with the GFS Retention settings by keeping backups for a longer period of time. — David Gugick

Regarding the GFS, in the end, I will still end up with many full backups increasing even more the total consumption right?

I couldn't find a comparison regarding the total storage used by the GFS vs a regular plan with monthly fulls.

Please advise on an e.g. of GFS policy that would allow me to have the last year of deleted files with the least usage of storage.

There are a lot of ways to keep more deleted files, but none provide complete assurance that you'll have them all, short of keeping all backups for 1 year.

If you set Keep Backup for 1 year, you'd have everything. You can set the full to whatever schedule you want and calculate how many full backups that will be. Every 30 days would require up to 13 full backups in storage. Ever 2 months would require 7. Every 3, requires 5. etc.

I do not think you'll get lower storage use using GFS given your requirements of saving only a year. GFS benefits are geared to restore points and longer term storage, when needed. If you ran monthly fulls and kept only the last 30 days of backups and used 12 Monthly GFS backups, you'd have up to 60 days of fulls + Incrementals (2 fulls + incrementals for each) and monthly full backups for the remainder of the year. So about 12 monthly fulls + 60 days of incrementals.

If you kept only 3 Years of GFS backups (and no monthly backups) you'd have 60 days (2 fulls _+ incrementals) + 3 more fulls fulls for the yearly backups, but you'd only have deleted file restore capability for 30 - 60 days.

You do get the ability to use Immutability with Amazon S3, Wasabi, and soon Backblaze B2 with your GFS backups for added backup protection.

If GFS, Immutability, long-term retention management, large file counts, restore speed, etc. are most important, then use the new backup format.

But as I tell customers who are running file backups: If the legacy format and its version-based retention and file-level to cloud object management works better for you, then stick with the legacy format. If your primary concerns are deleted file restoration and reduced storage, then the legacy format may be a better fit. Do not be concerned about using the older format. It's tested, very capable, and if it's right for you, use it.

Thanks for the clear explanation David.

My concern is the restore speed that with the new backup format is much better!
The problem is that we need to have extra storage consumption to meet requirements.

The major concern is that now the retention policy is set per the generation and not about the files, so we now need to worry on how long to keep the generation, at least until there is the new feature Consolidation and Reverse Full backup in place, right?

I guess that will be a game changes for this concern.

much of this is going to depend on what your customers need if you're in managed services. If you have restore SLAs in place and can't meet those SLAs using the legacy format then you'll have to move to the new format. And you'll need to negotiate with your customers how long you keep deleted files or how long they need them kept. Using that information You should be able to gauge the best choice in backup format and estimate backup storage requirements. Of course, there are things you can do to reduce backup storage costs as well. By making sure you're using the best cloud storage vendor for that customer. You could also mix the legacy format for local backups with the new backup format for cloud backups and adjust the retention on each to make sure you're meeting customer needs while still limiting cloud storage usage.

Thanks for the clarifications David.
We were trying to find a "cook recipe", but we are now looking at each customer specific needs.
If they want to store forever and don't mind on being slower on the restore, we go for the traditional backup format.
You want blazing fast, but don't mind keeping only the last 3 6 or 12 months of deleted data, let's use the new format.

Cheers

Sounds like a good plan.

I think you could probably decide on a few default options for customers and then have the conversations with them about anything they need over and above. For example you could use the new backup format for cloud backups with 6 months of deleted file restorability, and then open the conversation with the customers about whether or not they need longer retention or longer deleted file restorability, and move on from there. If many customers select the default, then you don't have to worry about a custom designed backup plan for each; but you always have that option.

Feel free to post back to the forum on your progress and how things are working out for you. Also let us know if you have any further questions I can help you with.

I think you could probably decide on a few default options for customers and then have the conversations with them about anything they need over and above. For example you could use the new backup format for cloud backups with 6 months of deleted file restorability, and then open the conversation with the customers about whether or not they need longer retention or longer deleted file restorability, and move on from there. If many customers select the default, then you don't have to worry about a custom designed backup plan for each; but you always hav — David Gugick

Definitely, that's what we came up.
Instead of full every 6 months which might be dangerous, we set up a baseline: to keep 3 months of Generations, run a Full every 3 months.

In the end, we will end up with 3-6 months of deleted files, because only when the third full backup runs after 6 months, shall delete the first generation and its differentials.

Is it correct my understanding?

Thanks again for the help David.

That's correct if you're keeping 3 months with a 3 Month Full Backup schedule.