using MongoDB.Driver;
using MongoDB.Driver.GridFS;
 
var r = new Random();
var content1 = new byte[10];
var content2 = new byte[36_000_000];
r.NextBytes(content1);
r.NextBytes(content2);
 
string fileId = "1";
 
var client = new MongoClient();
client.DropDatabase("TestDuplicate");
var db = client.GetDatabase("TestDuplicate");
var bucket = new GridFSBucket<string>(db);
 
bucket.UploadFromBytes(fileId, "unrelevant", content1);
 
try
{
    bucket.UploadFromBytes(fileId, "unrelevant", content2);
}
catch (MongoBulkWriteException e)
{
    Console.WriteLine(e.Message);
    // A bulk write operation resulted in one or more errors.
    // WriteErrors: [ { Category : "DuplicateKey", Code : 11000, Message : "E11000 duplicate key error collection: TestDuplicate.fs.chunks index: files_id_1_n_1 dup key: { files_id: "1", n: 0 }" } ]
}
 
try
{
    var read = bucket.DownloadAsBytes(fileId);
}
catch (GridFSChunkException e)
{
    Console.WriteLine(e.Message);
    // GridFS chunk 1 of file id 1 is missing
}