Once you correctly fill the username and password fields, you gain access to the DSM operating system, which, contrary to the competition (see QNAP), offers a windowed interface that renders it very familiar to most users.
The DSM is based on Linux, but its windowed interface makes it really easy to use since Synology custom-tailored it around novice users while still offering enhanced functions/abilities that will cover the needs of advanced users. It is, since it is based on Linux and especially cooked up for the hardware of Synology NAS servers, very light, which allows it to fully exploit the hardware of the DS213+ by using a minimal amount of system resources. An interesting fact about the DSM operating system is that it is stored across all installed disks, which allows you to boot and use the DiskStation even after removing any of the hard drives. This, of course, provides some extra security since all the crucial system files are stored on both disks and only if they all fail will you lose your configuration files. Nevertheless, you would, in such a case, worry less about the configuration files of the DSM and more about the data on the disks. However, provided cloud capabilities allow all of your data to be saved online, which means you never truly have to worry about HDD failures again.
Quick Start Wizard
The first time you start the DSM, you will be greeted by the Quick Start Wizard, which will walk you through the first steps to quickly configure the DS213+. First of all, you have to open the Storage Manager and create single or multiple volumes. You can't create RAID 5, 6, and 10 arrays since the DS213+ can only take two HDDs. It can only be configured for SHR RAID, RAID 1, RAID 0, and you can, of course, configure both disks as JBOD.
Let us talk a little more about the Hybrid RAID level (SHR) that is available through the "quick" option of the Volume Creation Wizard. SHR is an automated RAID Management system exclusively offered by Synology. It is meant for users who do not care for and do not want to know what the finer aspects of various RAID levels are. The SHR level of the DS213+ allows for a single disk worth of redundancy which means that the SHR volume can suffer the loss of one of the two disks, something it has in common with RAID 1. SHR is also the best option if you plan on installing different-sized disks into the NAS since it creates ideal partitions in order to exploit the full capacity of all disks. Not a single byte of disk space is left unused. More info about SHR is available here. Synology's option to skip disk check during RAID initialization, something that greatly accelerates RAID set-up, is interesting as well. But you have to be sure that your disks are in good condition and without any bad sectors, or your RAID will fail, which would endanger the data on those disks.
The second step of the Quick Start Wizard will prompt you to share some folders of your NAS server to make them accessible to users throughout the network. You can set the access rights for all users and groups once you create your shared folder.
The third step guides you through the process of enabling Windows, MAC, or NFS networking and introduces you to the File Station through which you can move files between your workstation and the NAS server.
The fourth step will prompt you to open the Package Manager inside of which you will find all available packages/applications for your NAS. You can install the ones you are interested in with the press of a button. Some of the more interesting packages are: antivirus, audio station, cloud station, download station, media server, photo station, surveillance station, time back-up, and iTuners if you have an iPhone or an iPad. There are, of course, many more packages available for download. You can take a look at some of the most interesting application packages by following this link.
You will prompted to install the Cloud Station package next; that is, if you haven't installed it already through step number four. Another relevant application for client PCs can be downloaded from the Synology Download center (the link is given by corresponding icons). Cloud station in DSM 4.1 supports two shared folders in sync, encrypted transmission, and HTTPS.
The final step helps you build your own cloud on the Internet and allows you to access DiskStation from anywhere in the world. Both are possible through the EZ-Internet Wizard that guides you through the entire process of setting up your Internet connection, doing the appropriate port forwarding on your router, setting up the firewall, and, finally, setting up the DDNS service in order to be able to locate your NAS server IP after it changes (if you have an Internet connection with dynamic IP like most home users).