Sample program on how to use Azure Append Blob. Perfect for "ever growing" files like: log-files, etc.

appendblob.cs

using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Auth;
using System;

namespace AppendBlobSample
{
    class Program
    {
        private static string StorageAccountName = "put-your-storage-account-name-here";
        private static string StorageAccountAccessKey = "put-your-storage-account-access-key-here";

        static void Main(string[] args)
        {
            var credentials = new StorageCredentials(StorageAccountName, StorageAccountAccessKey);
            var account = new CloudStorageAccount(credentials, useHttps: true);
            var client = account.CreateCloudBlobClient();

            var container = client.GetContainerReference(containerName: "tmp");
            container.CreateIfNotExists();
            var blob = container.GetAppendBlobReference(blobName: "log.txt");
            if (!blob.Exists()) blob.CreateOrReplace();

            Console.WriteLine("Enter various lines of text. End with an empty line.");

            string txt;
            while (!string.IsNullOrWhiteSpace(txt = Console.ReadLine()))
            {
                blob.AppendText(txt + Environment.NewLine);
            }

            Console.WriteLine("Blob now contains");
            Console.WriteLine(blob.DownloadText());

            Console.WriteLine("Press any key to exit");
            Console.ReadKey(true);
        }
    }
}