The FreeNAS distribution implements network-attached storage on top of the
ZFS filesystem; it was reviewed here back
in 2015. FreeNAS has always been based on FreeBSD, but now iXsystems, the
company behind this system, has announced
a new version, called TrueNAS SCALE, that will be based on Debian.
“Linux is a key requirement to achieve some of the SCALE project
goals“. More information about those goals will evidently be
forthcoming in the future.

Source: LWN.net – FreeNAS is coming to Linux