Help understanding Backup job GFS

[kevin.boddy]

Hi,

I am struggling to understand how the GFS works in a backup job.

The customer would like to keep a minimum 2-days worth of daily backups and also have a 1 month old retention point at all times.
We are backing up to immutable storage with 7-days of immutability configured.
Daily backups are configured with synthetic fulls on a Thursday.

How would I configure the GFS in the backup job to always keep the 1 month old retention point?

Thanks
Kevin

[pat_ren]

Edited my reply as I thought of a better way to explain it and my last response made no sense after I finished writing it and read it again.

Firstly if you're using 7 days of immutability you will want more than 7 days of retention, probably more like 10-15 but 7 would be the absolute minimum as this shouldn't be lower than your retention but should also factor in some block gen so maybe 14 days would be what I would pick.

As I understand it, with weekly full and 7-14 days of incrementals, one full out of the month ( you can pick ) would be flagged to get retained as a GFS restore point, which as it's a full backup can exist separate from the rest of the chain.

You would end up with something like a full backup (GFS claims this) then 7-14 days of incrementals and 1 more full, then another 7-14 days of incrementals and another full, at which point once you have at least 1 more full and at least 7-14 days of incrementals based on the settings, then the oldest non GFS full and incrementals will be deleted, then this repeats until the next month when you get a new full marked by GFS, then once the next 1-2 weekly fulls are created, and you have 7-14 days more incrementals, the oldest GFS restore point can be deleted.

Also keep in mind that with immutability, GFS restore points are also immutable for whatever the GFS period you select is, so in this case they would also be made immutable for a month. Not a big deal in this scenario but if you ever increase it to 3,6 or 12 months then those backups can be a problem if you ever need to reseed and can't delete them.

Hope this edited reply makes more sense than my first try.

[kevin.boddy]

Hi,

Thanks for the reply.

This is what I am seeing at a maximum. The daily backups vary between 7 and 14 retention points.

1x GFS monthly full retention point.
1x Weekly synthetic full.
6x Incrementals
1x Weekly synthetic full
6x Incrementals

The monthly full then gets deleted and there is no monthly full backup until the first week of the next month.
My oldest backup is now 14x days old.

How do i configure the job so that i've always got a 1 monthly old backup. I guess GFS would have to set to 2x monthly backups.

Thanks
Kevin

[kevin.boddy]

Hi,

Thanks for the reply.

This is what I am seeing at a maximum. The daily backups vary between 7 and 14 retention points.

1x GFS monthly full retention point.
1x Weekly synthetic full.
6x Incrementals
1x Weekly synthetic full
6x Incrementals

The monthly full then gets deleted and there is no monthly full backup until the first week of the next month.
My oldest backup is now 14x days old.

How do i configure the job so that i've always got a 1 monthly old backup. I guess GFS would have to set to 2x monthly backups.

Thanks
Kevin