For years we wondered why external hard drives didn't come with multiple USB ports so that two or more computers could work off of the same drive at once. Sadly, there isn't a simple way to connect two computers to a single hard drive, but we've found a better solution.
Every time we travel we bring along our trusty Synology NAS (Networked Attached Storage) box. The one we currently have isn't available anymore but the current version is the DS716+II. This small little box will hold two separate drives that will work together to back up your data and it will share this footage over a network connection. These NAS boxes can do a ton of different things but we only use them to backup our data and to access our data from multiple computers at once.
In the past I connected the NAS box to a standard five-port switch and then ran Ethernet cables from the switch to our laptops. This gives us around 110 MB/s read speeds with a wired connection. Recently I've swapped out our switch for the TP-Link C7 AC1750. This router has the same five Ethernet ports on the back so we can still use it wired but it will also broadcast our NAS box wirelessly as well. Sadly the top speeds we were able to get with any router on the market was around 45 MB/s. Also, unless your computer has multiple Wi-Fi chips, you won't be able to connect to the box and the Internet at the same time. It's not as good as a wired connection but it's nice to have the option.
If you're looking for a server solution while traveling or if you want more storage for your home, the DS716+II is a great choice because it has the ability to connect to a five-bay expansion unit to add even more storage. We use a much larger version of this in the Fstoppers office as our main server.
This post may read like an ad but we have no connection with Synology. We are just extremely satisfied customers and I wanted to pass this info along to anyone who may also need this type of solution.