Unfortunately the Pi's released so far are all based on the same architecture which utilizes a single USB 2.0 lane for networking as well as the USB ports. Trying to connect a drive to a Pi means it is limited to USB 2.0 speeds, and using networking at the same time cuts in on the available bandwidth. The Pi Foundation said the next generation will use a newer architecture, but the currently available ones are crippled in this manner. They are learning devices and not meant for what most people try to do with them.
There are other options out there for Pi-like devices that have multiple, faster I/O options from the likes of Pine64, FriendlyElec (FriendlyArm), Odroid and others which tend to have less or no support. You can look at some Options Available at AmeriDroid
. The companies mentioned supply working OS images. Alternatively you can look at the Options From Armbian
for Debian and Ubuntu based images.
After buying all of the extras to get an ARM device up and running, and getting it suitable to connect a drive for writing a significant amount of data usually ends up costing around the same as a cheap x86 machine. There are plenty of people using ARM devices in that way, but I personally don't see any clear winners. There are lots of x86 devices using similar or slightly more power with substantially more versatility because of all the connections they have such as SATA, PCI-E, USB 2/3, and networking.
You can set up the Pi as a POE camera with a POE hat and Pi camera (the CSI port isn't on the same USB bus as nearly everything else). I have one set up to look down my driveway, but it just broadcasts on the network where another machine can be used to record. A cheap Atom based board has worked fine for me in my testing, recording using Motion on Raspberry Pi x86 and other Linux distros.
It may be possible to do some recording using the Pi and only using motion activated recording, but it will quickly get saturated trying to juggle more than one camera.