The Raspberry Pi Zero/One is a capable FTP/SSH server, but for field deployments, I would consider the Raspberry Pi 3 Compute Module.
This article is mainly about what to do with an old Raspberry Pi 1 or Raspberry Pi Zero you have lying around.
- Cannot Install / Not working if Installed
- Extremely slow, maybe single patient user only
- slow, but perhaps usable for patient 1-3 users
- adequate, may handle a handful of users (family, small club)
- great, handles multiple concurrent users, not so much slower than a 10-year old Pentium 4 PC
Groupware (email/calendar) server
As of this writing, Citadel was the only known easy to install groupware server. Accessing features took a few seconds per click, and it didn’t seem that users accustomed to using Google or Office 365 would have the patience for Citadel on Raspberry Pi.
Like SSH below, the Raspberry Pi can handle a few connections at once, but may well be limited to less than raw Ethernet speeds due to:
- CPU: USB-Ethernet onboard conversion
- CPU: encryption (if using SSL/SSH, etc.)
- CPU: filesystem – if using external HDD with FUSE (NTFS,exfat,etc.)
- CPU: USB HDD – takes some CPU to manage the transfer from USB to external HDD
- SD card: read/write speed
Web LAMP server
I have not done this personally, but you can search for people using the Raspberry Pi as an NGINX or Wordpress server and it does seem to work live on their Raspberry Pi 1. example: dingleberrypi.com
Rank: 2 - 2.5
With LXDE, as of Aug 2013, with Raspbian the Raspberry Pi 1 is just too painfully slow to be used as a desktop replacement. Web browsing (e.g. Gmail) is painfully slow and only tolerable in desperate situations. The Beaglebone Black on the other hand is just fast enough that one MIGHT be able to use it with LXDE desktop.
SSH server (port forwarding, SSHFS, remote management)
Rank: 4 - 4.5
The Raspberry Pi does quite adequately in this regard – you will feel just a bit of the CPU limitation when using say < 5Mb/sec, perhaps due to the USB-Ethernet adapter internal to the Raspberry Pi 1 Model B as well as the SSH encryption itself–this shouldn’t be too hard to measure for the curious.
The Raspberry Pi FM transmitter works splendidly – the program can be modified to transmit narrowband (~ 5kHz) FM on the 2 meter ham band as well.