The MBWE II (white bar) is a redesign of WD's previous two-drive diskful NAS that comes in 2 and 4 TB configurations. Supported volume configurations include JBOD (individual drives), span (usually referred to as JBOD) and RAID 0 and 1. Only one RAID volume is supported and there is no RAID expansion or RAID level migration. The drives can be replaced by users but must be replaced with WD Caviar Green drives or won't be recognized.
The hardware platform is essentially the same as the redesigned single-drive MBWE, using an Oxford OXE810DSE SoC, which is also used in the Iomega Home Media Network Hard Drive. Rounding our the design is 128 MB of DDR2 RAM and an LSI ET1011C2 Gigabit Ethernet transceiver, which supports up to 9K jumbo frames. There is a single rear-mounted USB 2.0 port that accepts USB storage for sharing or NAS backkup. The two WD10EAVS-00D Caviar Green 1 TB drives in the 2 TB version are formatted using the HFS+ filesystem.
Power consumption measured 16 W active and 5 W with the drives spun down. There is no system fan, so the NAS is very quiet in operation.
Feature set is also similar to the single-drive MBWE. CIFS/SMB, AFP and NFS network file systems are supported and there is an FTP server that can be enabled for anonymous or account-based serving. Web based admin is supposed to also support secure HTTPS access, but we couldn't get it to work. On a more positive note, root access via SSH is supported and since the OS lives on the disk and not flash, changes to the filesystem are retained through reboots.
Media features include iTunes and Twonkymedia UPnP AV media servers The download service handles immediate or scheduled downloads of single HTTP or FTP URLs with settable simultaneous download limit and download bandwidth limiting. BitTorrent downloads are not supported.
For backup, 5 licenses of WD Anywhere Backup client (Memeo) are bundled for Windows and Mac OS. Backup (both directions) is supported between the NAS and attached USB drives, but it can't be scheduled. USB drive formats supported are FAT32, NTFS and HFS+.
The MBWE II turned in an average RAID 1 write performance using a Gigabit Ethernet connection of 17.1 MB/s for file sizes between 32 MB and 4 GB, with cached behavior not included in the average calculation. Average RAID 1 read performance was almost double, measuring 33.7 MB/s with the same conditions.
File copy performance using a Vista SP1 client under the same conditions (RAID 1, Gigabit LAN) was slightly lower for writes at 14.5 MB/s and also for reads at 28.8 MB/s. Backup speed to a FAT32 formatted RAID 0 drive measured 10 MB/s. Overall performance was better than the Cisco / Linksys Media Hub and about the same as NETGEAR's ReadyNAS Duo.