A general rule for Synology NAS naming, but there are some exceptions to this.
- DS (Disk Station) or RS (Rack Station) for tabletop or computer racking.
- First one or two digits are the maximum disks that can be supported, with extra-cost expansion units.
- Last two digits are the model year. Current year if released in fist half of the year, next year if second half.
- Suffix for the NAS series, if present.
For example, the DS209j is a desktop, two drive NAS from 2009 in the entry-level j-series. While my
DS1520+ is a five drive unit that supports two expansion units (each hold five drives) from 2020 in the plus series.
An exception would be my
DS218+ because it supports one expansion unit but is ‘2’ because the storage array cannot span between the two devices. Spanning storage array between NAS and expansion unit isn’t advised as there’re too many risks of something failing and taking the whole array down.
If you can stretch to the very new
DS223j then that would be the best j-series device and give you a lot longer life. The latest DSM 7 has recommended minimum RAM of 1 GB, and this has now only just happened for DS2
nnj devices with the 23.
If you can stretch further then the
DS224+ has only just been announced. It has the same CPU as my DS1520+ and I’m still very happy with it. You’ll find you can run it as a home server for more/all the packages, unlike the lower series. After this it’s more about adding more drive bays. Have a look at @Rusty’s reviews on his Blackvoid site.
Avoid any DS
nn15+ because these have the IntelAtom C2000 CPU and needed a fix to the circuit board. Some may not have had this done at a suitable time, so it’s best to avoid they secondhand if just to not have to worry about it. Google it and you’ll find many hits.