FRUUG - Front Range Unix Users Group
FRUUG home
meeting archive
about FRUUG
join FRUUG
contact info

Next-Generation Storage Area Networks

At our December, 2003 meeting, John Spiers of LeftHand Networks discussed next-generation storage area networks based in IP protocols. John started with an overview of some of the storage management issues facing administrators today. He showed various charts on storage, data and computing trends. He claimed that in the future there will be more seamless bridges between systems and networks (showed diagram of an InfiniBand network).

The installed base of storage devices is divided into Direct Attached (70%), Network Attached Storage (NAS - 5%), and Storage Area Networks (SAN - 25%). For IP SANs, there is a choice between a software initiator (kernel driver) or a dedicated offload engine on a card (still expensive). The software initiator may consume a significant percentage of the CPU (as much as 30% or more depending on the type of application load), however.

John then described the LeftHand Networks solution that includes several data services and virtualization. Their architecture uses a distributed systems approach to load balance and provide high availability. Storage is added a "brick" at a time, with dynamic resizing of existing volumes when you add storage. They use a Quorum cluster management to eliminate split brains.

They have a proprietary protocol called Advanced Ethernet Block Storage (AEBS is TCP/IP based) that enables the asymmetric virtualization. They keep block maps in the client so that they can vector directly to the appropriate brick for the needed blocks. They also support standard iSCSI via a proxy on one of the bricks that acts as a client to the other bricks using their proprietary protocol. They also use AEBS for remote replication and remote snapshots. They do over-provisioning of volumes with soft and hard thresholds for the automatic provisioning.

Their devices use Serial ATA drives, so they only do N-way mirrors (no RAID parity algorithms) due to the fact that raw storage is cheap. They currently use an authentication based on an IP addresses today, but are looking at CHAP (iSCSI) and IPSec for the future. They have an SNMP MIB for management, and are going to comply with SIM-S standards as well.

They have 1/2 TB and 2 TB bricks and have connected up to 60 at a time (largest customer uses 32). Denver Health is a big customer of theirs (EMC Shop) and likes the distributed storage (distributed bricks over multiple floors) that they can manage as a whole.

They OEM an off the shelf RAID controller and use Linux for their embedded OS where the clustering, management and fail-over run. They also OEM an Intel motherboard and the aforementioned Serial ATA Drives.

John then talked about some industry trends such as when iSCSI would be widely available.

Slides for John's talk are available (PDF 6MB).

Site Map Recruiter Info
February 15, 2009

February 2008: FRUUG Enters Quiescent Phase
After 27 years running, we're suspending operations.

Future Meetings:
None planned

Site by
Lone Eagle Systems, Inc.,
Hosted courtesy of Indra