As @damium@programming.dev says you may be able to do this with find command. This command lists all PDF files under ~/tmp that were created more than 7 days ago and does a directory listing. You could use this as a basis to move create an archive of individual files.
find ~/tmp -ctime +7 -iname "*pdf" -exec ls -rlht {} \;
The find command also has a -delete flag.
I have in the past used this combination to implement file management. I don’t have access to the script any more. I don’t remember why we used a shell script rather than logrotate as per @oddityoverseer@lemmy.world
My guesstimate is you have around 1,400 4K DVD rips. Do you need all of them?
You probably should look at RAID 6 with a cold spare (i.e. a drive sitting alongside the server.
ZFS allows you to create spare disks. ZFS spare disks are hot spares which are swapped in for faulty disks and swapped out when you replace the faulty disk.
I suggest that you calculate the cost to build this server, you should allow for NAS specific drives rather than the cheapest desktop drives.
You will need PCI to SATA cards to connect you drives.
I suggest that you look at the NAS builds on PC Part Picker.
Have a look at these pages
https://www.wundertech.net/diy-nas-build-guide/ https://nascompares.com/guide/build-your-own-nas-in-2024-should-you-bother/ https://www.storagereview.com/review/how-to-build-a-diy-nas-with-truenas-core
Finally check how much power and heat the server will produce. A server with that many drives will loud.