How would I architecture Direct Attached Storage?

Question

This is a sequel question to a previous one.

I would like to set up a home networking solution with Direct Attached Storage.

"Direct Attached Storage" seems to suggest that I would run cables (Ethernet, presumably) from two Macs to some kind of medium.

1. What is that medium? In particular, are we talking here specifically about SATA RAID rather than RAID? IIUC the former requires running not Ethernet cables but SATA cables (can these be 30-40 ft long?), where the latter requires attaching via USB to an Airport Extreme or similar.
2. Is a third Mac needed to act as a server?
3. Is macOS server needed?
4. What is the name of the software that you would run to actually "serve"?

Answer 1

DAS means you connect one or multiple external hard discs locally (e.g. by USB or SATA)

1) Then, you share them from this computer. What you need are standard external USB drives and a working home network.

2) You can share them using any Mac that is "always on" when the others are on

3) no, standard Mac OS will do

4) OSX. System preferences->Share->File Sharing

To connect, in the Finder select "Connect to Server..." under the Go menu.

Answer 2

I would like to set up a home networking solution with Direct Attached Storage.

Going on the premise of your linked (previous) question, which is to log into either one of your Macs and have access to your files in their current state, you need a shared storage solution.

Your network and the storage connections would be entirely separate entities.

1. Your medium could be SATA, SAS, SCSi, Fibre Channel, or 10GB copper.

   a. RAID is just Redundant Array of Inexpensive Disks and how you configure it is entirely up to you. The end result it you will have multiple (physical) disks that comprise and show as a single logical volume.

   b. SATA cables are limited to 1M. Ethernet is limited to 100M, Fibre Channel can go from 2M to 1.4KM depending on the speed and the fibre type.

   c. Anything over Ethernet is technically networking even if point-to-point (iSCSI is the most common, but not natively supported in macOS)

2. No. In this configuration, a third Mac is not needed.

3. MacOS Server is not needed as a third Mac (or any computer for that matter) is not needed. Adding a third Mac (presumably to attach to the storage device itself) turns this into a NAS configuration.

4. On a DAS setup, there's no need for software as the operating system will mount the shared volume in basically the same manner as you would a USB flash drive.

Bottom Line

While DAS will be super fast and convenient, it's really only good for servers and in some cases video editing where the user needs copious amounts of high performance, low latency storage.

If this is just for accessing a common set of files, there are much more efficient and cost effective solutions like a NAS or the cloud.