“There is not a lot of added value in commodity ‘storage bricks’”

Commented one feisty StorageMojo.com reader last week. I didn’t agree, but I didn’t have a ready answer, either. But now I do: Rackable Systems.

You may have heard of Rackable for their innovations in packaging systems: efficient DC power; half-depth servers mounted back-to-back with a central “chimney” for cooling; remote management; and a rapidly growing storage business.

What you didn’t know
RACK is profitable. They’ve been growing like a weed, doubling in size each of the last three years and are on track to do it again this year. They have sales of $1.9 million per employee, which is likely close to a Silicon Valley record. All this on gross margins in the low 20’s, just a few points higher than Dell.

It isn’t all hardware either
One of the fastest growing parts of their business is storage and their Terrascale clusters. They claim:

The Terrascale architecture is free of any serialized function that would limit performance scalability. . . . Terrascale software uses a lightweight, linearly scalable, on-demand cache coherency algorithm that guarantees that servers access the correct representation of any data block at any point in time.

I’ve dug into their white paper – which is better than most – called The TerrascaleTM Storage Cluster: A New Paradigm for Parallel I/O to Resilient
Network Storage
. It isn’t clear how they do all their magic from the paper. Nonetheless they are insistent in claiming that the system truly scales to hundreds of nodes. Here’s a precis of what I was able to glean.

Terrascale offers a:

  • Global name space
  • Global lock management service
  • Local cache coherence mechanism

The global name space means all the servers in the cluster see all the same files. The lock management ensures that data is written only when safe. The local cache coherence means that all servers know immediately when data is written, thanks to a write-through cache.

iSCSI to the rescue
Using open source software, Terrascale adds an iSCSI target kernal module that, in concert with a client iSCSI initiator, creates this highly parallel infrastructure. Above the Terrascale layers are standard Linux storage tools such as lvm, while below is the standard TCP/IP stack.

The global name space means that all storage is part of a pool. RACK offers low-cost RAID 5 storage and then use those as virtual disks to create a second layer of RAID across those for greater speed and availability. They claim their storage scales to the limit of aggregate network or storage bandwidth. Need more of either? Buy more and plug it in.

The StorageMojo.com take
RACK is currently focused on the high performance computing market where their pack ’em dense, stack ’em high and sell ’em cheap model is a hit. Yet it won’t take them too much longer before they will have to look to commercial markets for high growth. And there they have an excellent opportunity to make waves for conservative storage vendors – unless EMC or IBM buys them first – with their low margins and aggressive prise/performance. A company to watch and, if you’re in the market for more Mojo, a company to look at buying from.

Comments welcome, as always. Moderation turned on to keep the comment spam under control.