The DS411slim supports peripheral devices by means of one eSATA and two USB ports. The USB connectors can be found on the front and back panels of the case. The eSATA interface can only be used for external hard disks. It doesn't support Synology's exclusive multi-disk module. It’s simpler with USB: you can use hubs and have no limits as to the number of external disks.
Such disks can have multiple FAT32, NTFS, ext2, ext3 or ext4 partitions, each represented as a shared folder. The folder's name and access rights can be edited. The NAS will remember such changes and restore them as you reconnect the same disk. You can format the entire disk or a partition as FAT32, ext3 or ext4 in the NAS's web interface. A safe disconnect option is also available there.
Data from a flash disk connected to the front USB port can be quickly copied into a predefined NAS folder by pressing the respective button.
External disks can be shut down when not active. The NAS’s support for USB printers has been considerably expanded. Besides conventional network printing, the DS411slim supports the AirPrint feature for Apple's mobile devices and Google's Cloud Print. Both printing and scanning functions of all-in-ones can be used (but only in Windows). You first install all drivers on your PC and then use DSAssistant to add your all-in-one into your system.
When connected to an uninterruptible power supply, the NAS can monitor the power status via a USB cable and safely shut down according to a selected algorithm: when the battery charge is below certain level, immediately or after a predefined period of time. One UPS can be shared by several NASes via the integrated client-server system.
There is one more application for the NAS's USB ports. You can plug a Wi-Fi adapter into them to link the NAS to your wireless network. The official compatibility list names about 25 adapter models, most of which are 802.11n. The adapter will work as a second network interface without any routing features. If you plan to use the Audio Station feature, it can output audio via a USB-interfaced sound card. Thus, you can play audio on an external sound system right from the NAS.
Many of the NAS's services use the integrated clock. It can be set up manually or automatically via the internet.
The interface language is selected automatically, but you can choose it manually as well.
You can separately choose a language for email notifications and encoding for non-Unicode clients.
The NAS can check out for firmware updates and download them for installation after your approval.
You may want to reset the NAS to its factory state, for example to resell it. While doing this, the NAS can delete all data on its disks, or remove all data and configuration information, or reset the MySQL database password. User, group and shared folder settings can be saved and restored.
The DS411slim offers flexible monitoring tools. Besides informational pages that report you its firmware version, network parameters, and the status of its disks and services, there is a module that visually shows CPU, memory and LAN load levels. You can even view the most active OS processes in terms of CPU and memory usage.
The DS411slim has as many as 11 log files. Besides a standard list of system events, you can keep track of users' working with files and backup services. The NAS can report to the admin via email and use SMS for urgent notifications (the latter is a paid service).
The power management options allow to turn internal and external disks off when idle, create a schedule for the NAS work by, and make the NAS turn on automatically after a power failure. The latter option may be useful together with an UPS.