NAS The Fact, Jack
My enthusiasm for Broadcom's BCM4780 NASoC storage processor is by this time well documented; consider my April, 2004 Leading Edge writeup, or the fact that it subsequently garnered a Hot 100 Products of 2004 award from EDN. It's in production now, embedded within products from Maxtor (Shared Storage) and SimpleTech (SimpleShare), but neither takes full advantage of the NASoC's RAID capabilities.
You can use the Maxtor's Shared Storage device's USB ports to implement print servers or attach additional hard drives, but per my briefing with Maxtor at January's Consumer Electronics Show you can't create RAID arrangements of the resultant multi-drive array. SimpleTech's product does enable RAID clustering, according to Broadcom, but it's a clumsy multi-enclosure arrangement that's also performance-strapped by USB2's protocol overhead. A more elegant approach, in my mind, is a single enclosure containing a NASoC and two (JBOD, RAID 0 and/or RAID 1) or more (RAID 5 and/or 10) drives (see Wikipedia if you're unfamiliar with the preceding terminology).
As of Saturday, I've got such a system sitting at my feet. Broadcom sent me a BroadNAS reference design, housed within a CF-7021 enclosure, which I've promised to put through the wringer as a long-term beta tester. Right now it contains two drives, 160 GByte and 250 GByte (both Western Digital ATA-100, 7200 RPM, 2 MByte buffer), subdivided from the factory into numerous partitions; RAID 0, RAID 1, JBOD and unallocated. This single-drive, multi-partition flexibility is reminiscent of the Matrix RAID feature offered by Intel's Application Accelerator RAID Edition in conjunction with latest-generation core logic chipsets.
I reconfigured the system, via the comprehensive web browser-based setup screens, for two pools (and shares); a 160GByte RAID 1 set and 90GByte JBOD partition. In my limited testing so far, it's working like a charm, although the constant-RPM fan is a bit noisy. I did find one feature shortcoming; the BroadNAS software enables error notification (such as of impending drive failure through S.M.A.R.T. detection) via email, but it doesn't support SMTP servers (such as Gmail or Yahoo!) that require authentication. Broadcom's acknowledged the limitation and will be adding support to a future firmware release. I also wish the BroadNAS box supported Gigabit Ethernet; the 100 Mbit network connection is a performance bottleneck considering the drives inside have platter location-dependent ~30-50 MByte/sec sustained transfer rates. I'll report back via future Brian's Brain posts as I obtain more results, positive and/or negative.
My enthusiasm for RAID 1 is also well documented, and a recent posting on ExtremeTech by Loyd Case concurs with my observations and recommendations. Right now, RAID-capable network storage devices are pretty pricey, because in many cases when you take the top off you'll find a Linux-powered PC inside. Fastora's NAS-T2 (two drive-capable, but without drives included) costs around $700; the four-drive-capable NAS-T4 enclosure is $1000. Buffalo Technology's four-drive TeraStation is around $1/GByte and comes in 640 GByte, 1 TByte and 1.6 TByte variants. Heck, at those prices I might as well buy a $500 Mac mini and USB- or Firewire-tether a few SoftRAID-configured external HDDs to it!
Clearly, a sub-$20 (in high volume) Broadcom NASoC chip, which supports up to four drives, is going to strip a lot of cost out of the NAS system equation going forward. Bring it on! For another perspective on the topic, see PC Magazine's recent Storage Central review; only one of the seven home and small office NASs (the TeraStation) was RAID-capable out of the box, and the cheapest 'entry-level business-class NAS' was $3,599.
