Kernel/File System/Debian Version Upgrade Help (2 replies)

My Pogos and Dell Kace boxes are far out of date as shown below, although working fine. I need advice on sequencing the updates/upgrades. Update the kernel only, or the kernel and file system? What Debian version is the file system in Bodhi's current kernel/file system package? Or, do I upgrade the kernel only and then do a distribution upgrade as described in the wiki? Also, can the Oxnas Pogo even be upgraded to a later Debian version?

Thanks.

root@PogoMobile:~# uname -a
Linux PogoMobile 4.4.0-kirkwood-tld-1 #1 PREEMPT Mon Jan 25 20:35:24 PST 2016 armv5tel GNU/Linux

root@PogoP21:~# uname -a
Linux PogoP21 3.17.0-oxnas-tld-1 #1 SMP PREEMPT Sat Oct 25 15:59:43 PDT 2014 armv6l GNU/Linux