Some QNAP devices can be coaxed into running Debian.
I did the procedure on my (now 15yo) TS-410, mostly because the vendored Samba is not compatible with Windows 11 (I had turned-off all secondary services years ago). It took a few days to backup around 8TB of data to external drives. And AROUND 2 WEEKS to restore them (USB2 CPU overhead + RAID5 writes == SLOOOOOW).
Even to get the time down to 2 weeks, I really had to experiment with different modes of copying. My final setup was HDD <-USB3-> RPi4 <-GbE-> TS-410. This relieved TS-410 CPU from the overhead of running the USB stack. I also had to use rsync daemon on TS-410 to avoid the overhead of running rsync over SSH.
So, it's definitely not for the faint of heart, but if you go through the trouble, you can keep the box alive as off-site backup for a few more years.
Having said that, I have to commend QNAP for providing security updates for all this time. The latest firmware update for TS-410 is dated 2024-07-01 [1]. This is really going beyond and above supporting your product when it comes to consumer-level devices.
[1] https://www.qnap.com/en/download?model=ts-410&category=firmw...
In theory, one could fit an Arm RK3588 SBC with NVME-to-PCIe-to-HBA or NVME-to-SATA into half-depth JBOD case. That would give up 2x10G SFP, 2xNVME and ECC RAM.
The Marvell CN913x SoC has been shipping for 5 years, following the predecessor Armada SoC family released 10 years ago and used in multiple consumer NAS products, https://linuxgizmos.com/marvell-lifts-curtain-on-popular-nas.... Mainline Linux support for this SoC has benefited from years of contributions, while Marvell made incremental hardware improvements without losing previous Linux support.
As I understand, migrating to other hardware wouldn't be an issue if availability becomes an issue.
Debian offers flexibility and control, at the cost of time and effort. PhotoSync mobile apps will reliably sync mobile devices with NAS over standard protocols, including SSH/SFTP. A few mobile apps do work with self-hosted WebDAV and CalDAV. XPenology attempts to support Synology apps on standard Linux, without excluding standard Debian packages.
