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NAS v SAN for Mac

   Newer Technology is trying hard to be the great Mac accessory company they once were and have just introduced a MiniStack NAS. exhds1nas_330x260.gifThis diminuitive case is the same one as their MiniStack hard drive enclosures. I purchased two of the first generation hard drive enclosures after testing them for a magazine review. I really like how they were designed to keep drives cool through both passive cooling and a dual-speed fan.
   The idea of a small NAS (Network Attached Storage) is all well and good. There are plenty of other boxes out there, but Newer licensed Ximeta’s NDAS technology which touts the ability to connect to a network drive over ethernet like it was a local drive, say on USB. Interesting point in the Newer (and other NDAS drives) is that they do allow you to connect the NAS via USB as well. NDAS has promise and, if computer manufacturers start to implement the technology directly, this could be an incredible boon to computer users.
   This starts to approach the power of a SAN (Storage Area Network) where multiple users can connect to a shared drive (or drives) directly.
   But there are key differences between NAS, SAN and NDAS, as well as a few problems which I’ll illustrate here.


   Micronet offers the nearly orphaned (no press updates after July 2005) SANcube sancube.gif which can handle up to four Firewire 800 clients sharing the internal RAID system. At 65MB/s, this shared system is pretty fast, but it has been far outpaced by even single external SATA drives in head-to-head tests.
   Newer’s own NAS can connect to a computer via USB and to other computers over ethernet, but can it share files using both modes simultaneously? Newer makes a few big caveats clear, like “Simultaneous Write access for up to 20 PCs is possible, Write access for Macs is limited to a single user at a time. Best performance in PC environment is obtained with fewest connections” and “100Mb/s over Ethernet, 480Mb/s over USB 2.0”
   So to be as useful as it wants to be, it needs gigabit ethernet to even approach the speeds offered by USB 2.0. Moreover, those who need to share big storage the most often need to move big files– sometimes really big files. For them Firewire 800 is slow and SATA is direly needed. There are several NAS devices out there which offer better Mac user support (just one connected user? please.) and gigabit ethernet speeds. Some also support “jumbo frames” which put more data into a stream. This helps, but it’s still nowhere near as fast and nimble as a real SAN.
   What video pros really need is a SAN with an ethernet port. This way, those machines demanding the fastest throughput can be co-located with the SAN but the media can also be accessed elsewhere via ethernet so that others can look at and review media on the shared drives. AFAIK, there is no such solution currently available.
   indexraidshot.png In various discussions, the question “Why not a fibre channel system like an Xserve RAID” comes up. The answer is very high cost per seat. Not counting each fibre channel card that has to go in each computer (and won’t work with any iMac, MacBook, MacBook Pro, Mini, PowerBook, iBook, or anything but a tower) the base model Xserve RAID is $6,000 for 1 TB. If you just need three computers to share drives, the Xserve is $3000+ fibre per computer. Compare this to the SANcube at $4370 for 1.5 TB and uses FW-800 so it supports iMac, PowerBook, MacBook Pro as well as towers. In fact, FW-800 is not really a requirement for connectivity, it is just faster. You could use four FireWire 400 computers which is nearly every computer Apple has made since 2000. i.e. no additional cost for fibre channel cables, cards, software, drivers, etc.
   Admittedly, Apple has yet to put SATA ports on the back of any of their computers. But SATA blows FireWire 800 out of the water and has far more cross platform support than FireWire 800. The drawbacks are that SATA doesn’t daisy chain, nor provide power. Neither of which are issues for multiple computer heavy demand usage.
   So Mac users need:
1) Multilane SATA ports on the backplane of their computers.
2) A RAID box that supports multiple, concurren, direct users over SATA.
3) A RAID box that also has gigabit ethernet with jumbo frame support to enable additional people to access the media on the RAID server.

Currently, we are far from this solution, but each of these pieces are readily available in the marketplace. No one has put them together just yet.

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  1. June 3, 2008 at 4:29 pm

    Actually, someone HAS put it all together – check out 2Degrees Frost Data Solutions. SAN-over-Ethernet. Fabulous! http://www.2degreesfrost.com

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