How do I retrieve disk information in C#?

For most information, you can use the DriveInfo class.

using System;
using System.IO;

class Info {
    public static void Main() {
        DriveInfo[] drives = DriveInfo.GetDrives();
        foreach (DriveInfo drive in drives) {
            //There are more attributes you can use.
            //Check the MSDN link for a complete example.
            Console.WriteLine(drive.Name);
            if (drive.IsReady) Console.WriteLine(drive.TotalSize);
        }
    }
}

If you want to get information for single/specific drive at your local machine. You can do it as follow using DriveInfo class:

//C Drive Path, this is useful when you are about to find a Drive root from a Location Path.
string path = "C:\\Windows";

//Find its root directory i.e "C:\\"
string rootDir = Directory.GetDirectoryRoot(path);

//Get all information of Drive i.e C
DriveInfo driveInfo = new DriveInfo(rootDir); //you can pass Drive path here e.g   DriveInfo("C:\\")

long availableFreeSpace = driveInfo.AvailableFreeSpace;
string driveFormat = driveInfo.DriveFormat;
string name = driveInfo.Name;
long totalSize = driveInfo.TotalSize;

Use System.IO.DriveInfo class http://msdn.microsoft.com/en-us/library/system.io.driveinfo.aspx

Check the DriveInfo Class and see if it contains all the info that you need.

In ASP .NET Core 3.1, if you want to get code that works both on windows and on linux, you can get your drives as follows:

var drives = DriveInfo
    .GetDrives()
    .Where(d => d.DriveType == DriveType.Fixed)
    .Where(d => d.IsReady)
    .ToArray();

If you don't apply both wheres, you are going to get many drives if you run the code in linux (e.g. "/dev", "/sys", "/etc/hosts", etc.).

This is specially useful when developing an app to work in a Linux Docker container.