Add the external components sub-chapter

Includes the HDD glossary entry.

analytical.tex

@@ -110,6 +110,10 @@ Another choice lies in the way of storing the measured data on the server. For a
 On a client side of a proposed system, there are again three main language options. The first one is the already mentioned \texttt{Lua}. This language is simple, yet not terribly popular. The availability of the design resources might be limited. Second one is the ruler of the micro-controller world, plain \texttt{C}, suited for more experienced programmer, but providing the highest flexibility. The third choice is to use \texttt{C++} based eco-system, derived from \Gls{arduino}. This choice is far more superior, because it provides access to enormous resources and libraries readily available on the Internet with and addition to (mostly) cross-compatible code, which is a nice bonus.
 
 
+\subsection{External components}
+One entity, that was already mentioned, but still not depicted in the design considerations is the \gls{usb} storage. It requires both \gls{hw} and \gls{sw} to work, and is externally connected to the server node.
+
+Should the \gls{usb} storage be applied for a local data storage capability, in case when the server node cannot connect to the internet for a cloud upload and available non-volatile local memory is depleted, either a \Gls{flash} stick or an external \gls{hdd} should be used. Both require additional \gls{kernel} modules to work, in addition to the \gls{daemon}, that will handle the mounting process. In case of the \gls{hdd}, the capable power supply is needed to power both GL.inet board and the \gls{hdd} at the same time.
 
 
 

glossaries.tex

@@ -66,6 +66,7 @@
 \newacronym{sdio}{SDIO}{Secure Digital Input Output}
 \newacronym{qfn}{QFN}{Quad Flat No-leads}
 \newacronym{ssr}{SSR}{Solid-state relay}
+\newacronym{hdd}{HDD}{Hard-disk drive}
 
 \newglossaryentry{ethernet}{
 	name=ethernet,