SAN and NAS

To consider:
Buy a replacement harddisk with a bigger capacity could be much cheaper

Membangun Cloud File Server Dengan All In One Server Synology DiskStation - April 5, 2014

SAN vs. NAS: A diagram of the differences
In general if your application requires block I/O or there is a significant performance requirement, use a SAN. If it's file based I/O for the application or you need to share files and you want simple administration, use NAS

Nas-San Comparison
NAS:
Almost any machine that can connect to the LAN (or is interconnected to the LAN through a WAN) can use NFS, CIFS or HTTP protocol to connect to a NAS and share files.
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SAN:
Only server class devices with SCSI Fibre Channel can connect to the SAN. The Fibre Channel of the SAN has a limit of around 10km at best
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