If AoE is so good, why doesn't everyone use it?

Here's a list of reasons, that I have observed, for NOT using AoE storage.

1. Education --- most sysadmins have never heard of AoE, or know why its so simple to use.  Shame on our computer science eduction system, AoE should be part of Common Core!
2. Workload or lack of curiosity --- sysadmin workload leaves little time to explore new technology, and sysadmin's hate advertising.
3. FUD --- completive Fear, Uncertainty and Doubt is hard to ignore, and is used by all the big name vendors to compete with AoE products.
4. Perceived risk --- storage is so critical, and risk tolerance so low, it takes time to build confidence in technology you have never used, even though AoE storage has been reliably used by real paying customers for more than 11 years.
5. Job security --- why risk your job over something that is simpler to use and saves money, if something goes wrong you'll be to blame.  Fear is a powerful force.
6. L'Oreal hair color complex --- Isn't your data worth it? Buying the most expensive technology is justified because your data is worth it.  Wouldn't it be nice if money didn't matter?
7. Technology bigots --- make technology choices based upon feelings rather than facts.  There must be something wrong with AoE if everyone isn't using it.
8. NIH --- Not Invented Here is a powerful force in many minds, it develops into technology bigotry, and since AoE wasn't designed by a royal IEEE committee, who wants it.

None of these are very good reasons, are they?  Just give EtherDrive a try and I guarantee you'll become an rabid fan.  It's the perfect storage solution for cloud systems.  And I haven't come across a storage application that it can't support; including mission critical database, high speed streaming, high speed transaction process, server and desktop virtualization, or just massive backups that scale forever.  EtherDrive is even ideal for NSA's surveillance archive watching every move I make.

Simpatico, ZFS and EtherDrive storage, a perfect match.

Every now and then, the stars come into alignment, and two separate technologies, come together to become a perfect match.  The Zeta File System (ZFS) and EtherDrive SRX storage is just such a combination.   ZFS is becoming the filesystem of choice for many applications, and scaling is a big reason.  What ZFS needs is fast, scalable storage, but if the storage is simple, and economical, the combination becomes…"simpatico".

EtherDrive SRX is by far the fastest, simplest and least expensive network storage in the world, and when configured as Just-a-Bunch-Of-Disks (JBOD), the SRX perfectly matches the needs of a ZFS host.  With the free Solaris HBA driver, and HBA hardware priced at the same point as a standard GigE or 10GigE NIC, the ZFS advantage can be fully realized.

Many ZFS users are discovering how well EtherDrive meets their needs.  The next time you build a ZFS server, give EtherDrive a try and you will love it too.

Who needs 24/7 vendor support when your storage is EtherDrive smart.

Emergency situations in your data center happen, and they usually happen after everyone has gone home on Friday evening.   And when a company's data is at stake, vendor provided 24/7 emergency support can be easy to justify, even if it costs "an-arm-and-a-leg", and most storage vendors charge just that, "an-arm-and-a-leg".  But why not, isn't your data worth it?

Well I can't argue that your data isn't important, but I do think there is a better way to get piece of mind that you can handle any emergency situation, without being unnecessarily dependent on your storage vendor.

Just try EtherDrive storage.  It puts smart in storage.  Here's why I think EtherDrive is smart. EtherDrive storage is extremely flexible, and can be configured many ways to service any application.  Multiple LUNs of various sizes, RAID levels, global spare disks, mixed disk types, it can get pretty complex, and EtherDrive does it simply.  But here's where EtherDrive gets really smart, all this configuration data is stored on each of the disks in the appliance.

Why is this important?  Well, if the chassis fails (various hardware problems can happen with any platform) the disks contain all the information needed to survive the situation.  EtherDrive storage uses standard commodity hardware, and buying a complete spare chassis is good practice for any user.  EtherDrive disks can be quickly moved from a fail chassis to a spare chassis, without loosing any data or system configuration information.   In less than 15 minutes you can pull a chassis, replace it with a spare unit, and move the disks to the new chassis.  You can be back up and running without having to worry about configuration.  And its even foolproof, because it doesn't matter which disk slot the disks are put into in the new chassis.  You can scramble the disk locations, and it has no effect on the operation of the LUNs or RAID or spares, nothing changes.  You are just back up and in service without worry.

That's what I call EtherDrive smart storage, and why it makes sense for users to buy a spare chassis, at a fraction of the cost of 24/7 vendor support, and still have emergency response and recovery that is much faster than any vendor support program.  

Why is a connectionless protocol best for Ethernet SAN?

SAN traffic is simple commands to either write or read data, to persistent storage (usually disk drives) connected to a network—and this flow of data needs to be fast.

When speed is important, it matters how you transport data over the network.  Wasted steps and added complexity slow data flow.

It’s clear, Ethernet has won the technology race as the preferred transport mechanism for Storage Area Networks (SAN).  Ethernet is simpler, faster, and much less expensive than Fibre Channel.

But Ethernet defines an electrical method and basic frame/packet structure to carry data, it doesn’t define how data is to be transported.  Ethernet was designed to be a lossy network, primarily because early hardware implementations experienced network collisions, and some packets were lost in transmission.  So, applications that use Ethernet need to cope with occasional dropped packets.

Wrapping each packet in TCP guarantees lost packets are resent and delivered without corruption, but TCP also adds other features that are not always needed, especially on an Ethernet SAN.

For example, TCP establishes a “connection path” between the two ends of the network conversation.  This connect results in unintended consequences when TCP is used in a SAN.  To mitigate these consequences adds complexity.  I’ll explain more later.

ATA-over-Ethernet (AoE):   SAN without Complexity

AoE is an IEEE registered Ethernet frame type (0x88A2), and the AoE protocol includes important features that enable Ethernet to transport data efficiently and reliably.  AoE accomplishes some of the things provided by TCP, but without all the unnecessary stuff for a SAN application.

First each AoE frame (packet) is given a unique tag number.  All AoE packets, initiated by the host (initiator) are acknowledged by the EtherDrive storage device (target) echoing the packets tag number.  If a packet has not been acknowledged the host will resend it with a new reference tag number.  Standard Ethernet frame CRC will detect corrupt packets and discard them.

That’s it!  We don’t need to reorder the sequence of received data since the data is already identified by its block address, and we don’t need to route the packets with IP addresses when they stay within the local network.

Okay, so what happens when you use AoE as the storage protocol?

As I mentioned earlier, everyone wants the data flow between the storage device and the host (server) to be as fast as possible.  GigE and 10GigE links are used in an Ethernet SAN fabric.  More ports at the initiator and more ports at the target, provide more bandwidth for more data flow.  And multiple paths through the network also provide redundancy in case a link is broken.

In an iSCSI SAN, the TCP part of the protocol sets up a connection from one port on the initiator to one port on the target.  If more than one port is available on the initiator or target, the TCP connection won’t use it without additional software to manage these multi-path connections.  And as the number of available ports connected to the SAN is increased, the number of connection possibilities grows exponentially.  Each possible path presents a new instance of the same target LUN, making management much more complicated.

Connectionless Simplicity

AoE is a connectionless protocol and has the advantage of being able to flood the network with as many packets as the ports and paths between initiator and target can handle.

The AoE initiator will round robin packets between all available ports, load balancing the flow, for maximum throughput speed.  The LUNs are presented as a single instance to the host, no mater how many paths are being used for the data flow.  If the fabric of the SAN is changed, or new paths added/removed, AoE just naturally works.  Links can fail and be restored and the AoE flow automatically adapts to the available bandwidth.

That’s why AoE is better than iSCSI, it’s connectionless.  It's simpler to understand, and easier to use.  It just works.....and that's what makes EtherDrive storage so fast.

Confessions of an EtherDrive user.

Some time ago, I was speaking with an EtherDrive storage user about how he was using the product.

Well, she said, it all started several years ago.  I'm a system integrator and I was contracted by a nearby University to come up with a storage solution for some class room lectures that had been recorded, and used periodically across the campus.  It was considered a low priority project, so the system cost was important. 

We started this first project with EtherDrive SR1521's attached to a Linux server.  It went together quickly and worked exactly as planned.  The organization was surprised at how inexpensive the system was.  EtherDrive has built its reputation by providing great value, and reliability.  As is normal in campus life, word spreads when something new is tried and the experience is good.   

Soon I had another department at the University asking if EtherDrive might work for the campus security system.  They were expanding the number of security cameras around the campus and needed something that could expand easily.  Again we used EtherDrive SR storage and a Linux server, to build a really nice way to store and retrieve recorded videos from hundreds of IP cameras. And as the storage needs grew, we just added more EtherDrive SR's to the SAN.  We didn't need to change the Linux server, it just had more storage to work with. 

Word spread and the next request came from the main IT department of the University.  They needed some low cost backup disk storage, and they were willing to give EtherDrive a try.  They were sure, it wasn't going to be fast enough or good enough for their tier 1 applications, but for a lowly backup job, they decided to give EtherDrive a try.  There were many skeptics and some real technology bigots in that organization, so the trial had lots of critical eyes watching.  The system installed so quickly and the testing ran so smoothy, many in the IT department became EtherDrive fans. 

Next was the medical science department.  They had huge storage needs for a cluster of Linux servers sharing SAN storage, for their new genome sequencing projects.  This was a high performance application that needed to scale, but still be affordable.  A 10GigE SAN was constructed and they installed more than a dozen EtherDrive SRX storage appliances.  This same architecture has been replicated and is being used by many Universities around the world.  The genome sequencing people must talk a lot about what they are doing. 

As the University started moving into server virtualizing, they went with VMware, and after initially using iSCSI, they switched to EtherDrive SRX Storage.  EtherDrive storage can be configured to satisfy all the redundancy and reliability that virtualization environments require. 

The bottom line was, that each and every application could be supported with EtherDrive storage.  Its just simple to understand when you realize EtherDrive is just a disk (or LUN) on the network.  

Since that early conversation with my system integrator friend, I have yet to hear of any application that can not be satisfied by EtherDrive storage.  Users can install SATA drives and achieve lowest cost per TeraByte, or install SAS or SSD disks and achieve maximum performance and still have the lowest cost.  

"Simple SAN Storage" isn't an oxymoron. EtherDrive SRX storage appliance proves it.

The EtherDrive SRX storage appliance uses standard Ethernet as the SAN network.  No special enhancements are needed, just plain old lossy Ethernet.  The SAN topology can be a mix of GigE and 10GigE with many paths between devices on the SAN.

EtherDrive storage uses the open ATA-over-Ethernet (AoE) protocol to put disk I/O directly into Ethernet frames.  The protocol is connection-less and includes self discovery of storage by the initiator, and packet tagging with acknowledgement and retransmission to insure delivery.   The initiator (server) and target (storage), don't need IP connections or TCP processing.  AoE packets don't require a router, just an Ethernet switch, and VPN security can be used, but is not is not required.  This means packets are secure, flow fast, and stay within the local SAN.

An EtherDrive storage appliance is truly simple to use.  It can be installed and configured in less than 5 minutes, even if it's the first time you do it.  The software boots up and is ready to use in less than 20 seconds.  All the configuration data is stored on the disks; so, in a hardware failure emergency, disks can be moved from one appliance to another without loosing data.  It's simple to get your system back up without making a mistake.

EtherDrive storage appliances can be installed with multiple Ethernet interfaces, and users can have multiple Ethernet interfaces on the initiator.  AoE packets simply flood all available paths on the SAN, without any user configuration.   Net result is a SAN that is fast, fault tolerant and simple to understand.

EtherDrive storage makes SAN about as simple as it can be.  You would think it might cost more, to make it simple, but EtherDrive continues to offer the storage industries best value.  Check out etherdrive.com

What does EtherDrive 8 mean for Storage System Integrators?

When Brantley Coile acquired the CorOS copyrights for EtherDrive SRX and VSX products, he promised to continue the development of the AoE storage concept.  EtherDrive 8 is the new project that  is fulfilling that promise.  See www.thebrantleycoilecompany.com/ (TBCC) for details about EtherDrive 8.

Coraid's business model was similar to most of the big name storage vendors; to manufacturer and sell storage hardware with software inside.  The only way that users or system integrators could get EtherDrive SRX or VSX storage was to buy a chassis with disks and software from Coraid.  The basic hardware platform for SRX and VSX is server chassis hardware from SuperMicro Inc..  SuperMicro continues to offer high quality, reliable, leading edge hardware designs, and has established a worldwide sales, service and support network.  SuperMicro hardware is available from local suppliers all over the world.  Over the years, Coraid received many requests from users and system integrators to just sell the CorOS Disk-on-Module (DOM).  This was especially interesting for users outside the USA.  Why pay for heavy hardware to be shipped from the USA, when the same chassis can be purchased locally.  We never sold just DOMs but, in the early days (in 2005-2009), Coraid sold assembled and tested chassis with the DOM but allowed users to install their own disks.  In 2009, following the Series A round of VC investment and installation of a new management team, this policy changed and mandated that users and resellers buy SRX with disks from Coraid.  Obviously this raised the price per SRX significantly.

TBCC operates as a software only business.  EtherDrive 8 is available as a software license.  System Integrators are able to download unlocked binary files onto a common USB dongle.  Plugging the USB dongle into a suitable multi-disk server chassis will allow the server to boot and become an EtherDrive 8 storage appliance.   The cost benefits to the user are huge.  No more price markup from Coraid for the SuperMicro chassis, CPU, DRAM or disk drives.

A list of recommended SuperMicro hardware, CPU, Memory, and Disks is located on the TBCC website.  Storage System Integrators can now easily build and support a simple storage appliance with a 10 year proven history of data storage reliability, superior performance, and unmatched value.