What I've got:
- The 40-pin 528 MB B+ Raspberry Pi
- Five SATA hard disk drives
1) Is it best to use the four USB ports or find some kind of adapter for the 40-pin GPIO?
2) What do I need to make these five drives into a NAS with the Raspberry Pi?
Raspberry Pi Stack Exchange is a question and answer site for users and developers of hardware and software for Raspberry Pi. It only takes a minute to sign up.Sign up to join this community
I realize this is an old thread but it's still high on the Google ratings so an update. I've just built a NAS using a Raspberry Pi 4+ 4GB and four external 1-TB backup drives (Seagate Basic Portable STX1000400). The Pi's power over USB is insufficient to run four spindles, so it requires a powered USB hub, but this also has the advantage of spinning all four drives on USB 3.0 ports.
For setup I used RicMedia's excellent guide here: https://www.ricmedia.com/build-raspberry-pi3-raid-nas-server/. I then added WebMin for easier administration, and smartmontools (https://www.smartmontools.org/) to monitor the SMART status of each drive (note, watch the hardware compatibility on smartmontools, as not all USB drives play nice with smartctl over UAS).
The array won't break any speed records, but I have copied a single 1GB file to and from a Windows 10Pro PC over ethernet in about 9 seconds each way. When backing up a huge folder the backup went at about 1GB every 30 seconds. And if I ever want to expand, there's still another free USB3 port on the Pi, so another USB hub and set of drives should be hot-mountable (haven't tried this).
1) The GPIO is useless for this purpose.
2) Your best shot is using 5 USB to SATA converters or one that provides 5 SATA ports on the same USB port. However, both of these solutions would be pretty slow, since the Raspberry PI's USB ports are all coming from a single USB port on the SoC. This means that you'll be limited by the 480Mbps of this single USB port. To make it worse, the Ethernet port is also actually coming from this single USB port, so, if you're downloading from the PI, in theory, you'll be sharing a bandwidth of 480-100=380Mbps over the 5 drives.
If all you want from a RAID setup is increased storage space and redundancy, go ahead. If speed is all you want, anything that doesn't already come wiht 5 SATA ports will be a bad idea in general for this setup.