Backup copy clarification

[briggs]

Morning.
I have a file server, which even with compression and dedup, weighs in at almost 1TB for a full backup.
My backup of this server is done every 12 hours M-F, and a full each month. The retention is set to 90 restore points, so I get over 2 months worth retained.
I then have a backup copy job, for long term retention. I would like to retain a years worth of monthly backups ideally, so 12 months retention.
If I set the backup copy job to retain 12 monthly restore points, would that be 12 full backups? Or 1 full plus 11 incremental? I'm just trying to forecast how I can achieve the longest retention period, without running out of disk space.
I've looked in the documentation and have got a little lost, I will read through it again, but in the mean time, maybe a seasoned pro could educate me on the best way to achieve a high retention for an important server, without running out of disk space. The target for the backup copy is a NAS with 10TB by the way...

Thanks, Alan

[foggy]

If I set the backup copy job to retain 12 monthly restore points, would that be 12 full backups? Or 1 full plus 11 incremental?

Alan, each GFS restore point is a separate VBK. Only regular retention backup chain restore points are stored as increments.

I've looked in the documentation and have got a little lost, I will read through it again

I bet if you read it again, specifically this part, you will get a complete understanding of how backup copy job works. But still, feel free to ask for clarification here, if required!