Server walkthrough: Taking apart the HP Proliant D...
The HP DL380 G6 has the option for an integrated storage controller (HP SmartArray P410i) for SAS or SATA drives ('3'). It has 512MB of battery-backed write cache, which means that cached instructions are not lost in the event of a power failure ('1'). The SD card slot can be used as a boot device ('2').
Server walkthrough: Taking apart the HP Proliant DL380 G6 server