The NAS is connected to a LAN via two Gigabit Ethernet ports with support for up to 16,000-byte Jumbo Frames. Each port permits both manual and automatic IP address setup. The ports can be used in pair in load balancing or fault tolerant modes, which must be supported on the side of the switch. The second (LAN) port can also be used for an independent connection. In the latter case, the NAS can work as a simple NAT router, particularly working as a DHCP server for a LAN segment.
The NAS can accommodate up four HDDs. The integrated tools allow you to see their model names, firmware versions, and a few SMART parameters, including temperature. The HDDs can be turned off when idle. The idle period before turning off can be set at 30 to 300 minutes.
There are about 30 models from the leading brands on the compatibility list you can download from the manufacturer’s website. The list includes 1.5TB and 2TB HDDs, so you can have up to 8TB (if you don’t need fault tolerance) or 6TB (in RAID5 mode) of storage.
Choosing RAID parameters is an important step in setting any NAS up. The N4100PRO supports JBOD, RAID 0, 1, 5, 6 and 10. For fault-tolerant arrays you can assign a replacement disk that will be used automatically in case of a failure. When creating disk volumes, you can choose the size of a stripe (from 4KB to 4MB, except for RAID1), which is a rare option in NASes. Migration without data loss is supported as a means to increase the array’s capacity or type. Particularly, you can add disks to RAID0 and RAID5 arrays and convert RAID0 or RAID1 into RAID5. You can also sequentially replace HDDs with higher-capacity ones in RAID1 and RAID5 arrays. The NAS supports only one RAID array simultaneously, which is a limitation. For a 4-disk NAS, the option of building multiple arrays would be appealing.
I emulated a HDD failure by powering it off. The NAS reacted with its indicators and sound alarm, appropriate entries in log files, and an email notification. The sound alarm is quite irritating, so you may want to turn it off in the settings. When the failed HDD is replaced, the array is restored automatically. When done, the NAS sends an email notification that the array is okay.
The HDDs seem to be partitioned in a standard way: 2GB for the swap file and the rest for data. To remind you, the main part of the OS is stored in a 128MB flash module. However, my first attempt to access the disk (one HDD as a JBOD) under Linux failed. On further investigation, I found out that the NAS had a rather complex way of storing data. I first had to use the mdadm utility to “recover” the data partition. Then I found an LVM volume on it with two EXT3 partitions: one with user data proper and another (about 1GB large) with additional system files. The system partition is used to store logs, some settings and auxiliary files of the autonomous boot-up system. Any additional modules installed by the user are stored on the data partition. If it is deleted (for example, to change the type of the RAID array), those modules are deleted as well. If you have any concerns about the health of your file system, you can start the NAS in a special mode and run an error check procedure via the web-interface. When the file system is being scanned for errors, you will see the operation progress and the NAS will be inaccessible.
The N4100PRO supports all modern file access protocols: SMB/CIFS, AFP, FTP, NFS. For NFS, you specify client IPs and access type (read-only or read/write). The first three protocols traditionally use usernames and passwords for access control. Besides the integrated user database, you can use the one available in the Windows domain. User groups can be created for easier management. Access rights are typical: no access, read-only, full access. To facilitate the entry of many user records, importing from a text file is supported. The single administrator’s password is specified on an individual page.
Each protocol can be enabled apart from others. They don’t have special settings except for FTP. With FTP, you can choose the port to use for FTP, anonymous user capabilities (no access, read-only, reading and writing), download and upload speed limits, codepage. You may want to choose UTF-8 which supports Cyrillic and hieroglyphic filenames in any OS, including Mac OS X. The NAS is compatible with the Mac’s integrated backup tool Time Machine, although it takes some setup to run it for the first time.
Besides default public folders, the user can create his own folders and assign access rights to them. A folder can be made freely accessible to anyone or hidden. Traditionally for Thecus products, ISO images can be mounted into the NAS’s file system. This may be handy as the client can access them via the network without installing special software.
As additional options, you can disable guest access on a Windows network and the network recycle bin for deleted files.
The NAS can be found on the LAN using UPnP and Bonjour protocols.
To sum up, the N4100PRO has optimal basic functionality. It supports all modern protocols and their parameters and can be used with any platform or OS. FTP encryption is missing but it is already implemented in beta firmware.