QNAP TS-435XeU
Always-on primary NAS running QTS. 3×24 TB Seagate IronWolf Pro in RAID5 (~48 TB nominal) plus a 1 TB SSD cache. It has a direct 10G link to Cthulhu and a separate 1G point-to-point link to the HP backup server.
HP MicroServer Gen10
TrueNAS on an AMD Opteron X3216 with 16 GB RAM. A 128 GB SSD replaces the optical drive for the OS, two 1 TB SSDs mirror cache, and 2×24 TB data drives mirror the backup pool.
Games are not sacred
Two Samsung 860 EVO 1 TB volumes hold normal games and are not backed up. They can be downloaded again. WoW Classic is the exception because years of addons, UI, Grid healer setup and keybinds are far more annoying to rebuild than the game itself.
Primary history on QNAP
Important shares use snapshots three times per day with roughly three months of retention. HBS collects selected client data. Public and private GitHub repositories are also pulled nightly with a dedicated read-only SSH key: the NAS may fetch, but it cannot push or delete upstream.
Phone storage is deliberately selective. Keeper photos, holiday pictures, files and obviously CAT PICTURES :D are sent through LocalSend to Supermicro B and then onto QNAP; endless group-chat debris is not automatically archived.
primary + snapshots→direct 1GHP TrueNAS
secondary history
The HP only wakes up for backup work
The MicroServer normally powers up about twice per week using RTC scheduling with Wake-on-LAN as a redundant start path. It pulls from QNAP over its own direct 1GbE subnet. Cthulhu reaches it separately over 10GbE.
Its script keeps roughly one month of history for /mnt/Homelab and about two weeks for /home/nebu. Relevant ZFS datasets use native encryption and unlock automatically at boot.
Activity-aware shutdown
Every ten minutes the backup machine checks whether TrueNAS is still busy and whether relevant data remains in zram. If work is still happening, it waits another ten minutes. When idle, it shuts down.
If the backup fails or the source disappears, it deliberately stays powered on. That failure mode was tested by disconnecting QNAP: the HP remained sitting there visibly on instead of pretending everything went fine.
“If GitHub and the final HP backup cannot rebuild Cthulhu, the backup is not good enough.”
Disaster recovery is actually tested
Occasionally Cthulhu is rebuilt as a VM for fun using only GitHub plus the final HP backup tier — not convenient copies from the live workstation. The test includes the NixOS configuration, home directory, .config and even the wallpaper. Individual restores are tested too.
The logic is simple: if the final tier restores correctly, the QNAP-to-HP path also had to work.