The best way to get flash memory into computers isn’t to replace HDDs but to augment them.  For a vast majority of computer users the amount of storage they need is beyond what they can afford with flash memory alone.  This trend is liable not to change in the future even as the costs of flash memory go down because HDDs will increase in storage capacity  as well and the storage requirements of these users will increase as least as fast or perhaps even faster.   However, these users would love to get a higher performing computer and putting some flash memory in combination with a hard disk drive could be a very attractive means to do this. Hybrid HDDs that include some flash memory in the HDD are one approach but flash memory can also be installed in a computer motherboard or installed as a second drive.   A recent report from Coughlin Associates and Objective  Analysis explores these hybrid and paired storage and memory architectures.  The main requirement to accomplish the performance and cost advantages of a paired storage systems in managing what is stored on the flash memory, and what on the hard disk drive.  There are several software tools described in the report to provide this storage management.  Paired and hybrid storage can also reduce system power use. The combination of flash memory and HDDs is so compelling that the authors project a 53% adoption rate in desktop computers and a 25% adoption rate in notebook computers by 2016.  Furthermore, today’s media tablets will not provide for the needs of many business and power users who would like mobile products with more capability than can be provided by today’s tablets.  This will lead to a new category of “fat tablet” computers that combine some flash memory with hard disk drives as well as other enhancements to meet this market need.  The report projects that 40% of the total tablet market will be “fat tablets” by 2016. The report can be ordered from Coughlin Associates at:  http://www.tomcoughlin.com/techpapers.htm.

SSSI will be in booth 616 at Storage Networking World in the Santa Clara Convention Center on April 5-6.  The booths are open 12:30-3:00PM and 5:30-7:30PM on Tuesday, plus 11:00AM-3:00PM on Wednesday. The SSSI booth will feature a demonstration of the Performance Test Specification by Calypso on their tester.  White papers and other information on SSDs will be available as well. SSSI has been working with Storage Strategies NOW (www.ssg-now.com) on a survey about solid state storage technology adoption, practice, and deployment.  We’ll have copies of the survey in the booth or it can be completed on-line at http://www.surveygizmo.com/s3/476489/Solid-State-and-High-Speed-Memory-Adoption-Practice-and-Deployment.  Qualified responses will receive a $7.50 Amazon gift card or have the option to have it donated to the Red Cross Japan Earthquake and Pacific Tsunami fund. Come to SNW and ask SSSI about SSDs.

by: Gary Gumanow

Last Wednesday (2/24/11), I hosted an Ethernet Storage Forum iSCSI SIG webinar with representatives from Emulex and NetApp to discuss the benefits of iSCSI storage networks in SQL application environments. You can catch a recording of the webcast on BrightTalk here.

The webinar was well attended, and while we received so many great questions during the webinar we just didn’t have time to answer all of them. Which brings us to this blogpost. We have included answers to these unanswered questions in our blog below.
We’ll be hosting another webinar real soon, so please check back for upcoming ESF iSCSI SIG topics. You’ll be able to register for this event shortly on BrightTalk.com.

Let’s get to the questions. We took the liberty of editing the questions for clarity. Please feel free to comment if we misinterpreted the question.

Question: Is TRILL needed in the data center to avoid pausing of traffic while extending the number of links that can be used?

Answer: The Internet Engineering Task Force (IETF) has developed a new shortest path frame Layer 2 (L2) routing protocol for multi-hop environments. The new protocol is called Transparent Interconnection of Lots of Links, or TRILL. TRILL will enable multipathing for L2 networks and remove the restrictions placed on data center environments by STP single-path networks.

Although TRILL may serve as an alternative to STP, it doesn’t require that STP be removed from an Ethernet infrastructure. Hybrid solutions that use both STP and TRILL are not only possible but also will be the norm for at least the near-term future. TRILL will also not automatically eliminate the risk of a single point of failure, especially in hybrid environments.

Another area where TRILL is not expected to play a role is the routing of traffic across L3 routers. TRILL is expected to operate within a single subnet. While the IETF draft standard document mentions the potential for tunneling data, it is unlikely that TRILL will evolve in a way that will expand its role to cover cross-L3 router traffic. Existing and well-established protocols such as Multiprotocol Label Switching (MPLS) and Virtual Private LAN Service (VPLS) cover these areas and are expected to continue to do so.

In summary, TRILL will help multipathing for L2 networks.

Question: How do you calculate bandwidth when you only have IOPS?
Answer: The mathematical formula to calculate bandwidth is a function of IOPS and I/O size. The formula is simply IOP x I/O size. Example: 10,000 IOPS x 4k block size (4096 bytes) = 40.9 MB/sec.

Question: When deploying FCoE, must all 10GbE switches support Data Center Bridging (DCB) and FCoE? Or can some pass through FCoE?
Answer: Today, in order to deploy FCoE, all switches in the data path must support both FCoE forwarding and DCB. Future standards include proposals to allow pass through of FCoE commands without having to support Fibre Channel services. This will allow for more cost effective networks where not all switch layers are needed to support the FCoE storage protocol.
Question: iSCSI performance is comparable to FC and FCoE. Do you expect to see iSCSI overtake FC in the near future?
Answer: FCoE deployments are still very small compared to traditional Fibre Channel and iSCSI. However, industry projections by several analyst firms indicate that Ethernet storage protocols, such as iSCSI and FCoE, will overtake traditional Fibre Channel due to increased focus on shared data center infrastructures to address applications, such as private and public clouds. But, even the most aggressive forecasts don’t show this cross over for several years from now.
Customers looking to deploy new data centers are more likely today to consider iSCSI than in the past. Customers with existing Fibre Channel investments are likely to transition to FCoE in order to extend the investment of their existing FC storage assets. In either case, transitioning to 10Gb Ethernet with DCB capability offers the flexibility to do both.

Question: With 16Gb/s FC ratified, what product considerations would be considered by disk manufacturers?
Answer: We can’t speak to what disk manufacturers will or won’t do regarding 16Gb/s disks. But, the current trend is to move away from Fibre Channel disk drives in favor of Serial Attached SCSI (SAS) and SATA disks as well as SSDs. 16Gb Fibre Channel will be a reality and will play in the data center. But, the prediction of some vendors is that the adoption rate will be much slower than previous generations.
Question: Why move to 10GbE if you have 8Gb Fibre Channel? The price is about the same, right?
Answer: If your only network requirement is block storage, then Fibre Channel provides a high performance network to address that requirement. However, if you have a mixture of networking needs, such as NAS, block storage, and LAN, then moving to 10GbE provides sufficient bandwidth and flexibility to support multiple traffic types with fewer resources and with lower overall cost.
Question: Is the representation of number of links accurate when comparing Ethernet to Fibre Channel. Your overall bandwidth of the wire may be close, but when including protocol overheads, the real bandwidth isn’t an accurate comparison. Example: FC protocol overhead is only 5% vs TCP at 25%. iSCSI framing adds another 4%. So your math on how many FC cables equal 10 Gbps cables is not a fair comparison.

Answer: As pointed out in the question, comparing protocol performance requires more than just a comparison of wire rates of the physical transports. Based upon protocol efficiency, one could conclude that the comparison between FC and TCP/IP is unfair as designed because Fibre Channel should have produced greater data throughput from a comparable wire rate. However, the data in this case shows that iSCSI offers comparable performance in a real world application environment, rather than just a benchmark test. The focus of the presentation was iSCSI. FCoE and FC were only meant to provide a reference points. The comparisons were not intended to be exact nor precise. 10GbE and iSCSI offers the performance to satisfy business critical performance requirements. Customers looking to deploy a storage network should consider a proof of concept to ensure that a new solution can satisfy their specific application requirements.

Question: Two FC switches were used during this testing. Was it to solve an operation risk of no single point of failure?
Answer: The use of two switches was due to hardware limitation. Each switch had 8-ports and the test required 8 ports at the target and the host. Since this was a lab setup, we weren’t configuring for HA. However, the recommendation for any production environment would be to use redundant switches. This would apply for iSCSI storage networks as well.
Question: How can iSCSI match all the distributed management and security capabilities of Fibre Channel / FCoE such as FLOGI, integrated name server, zoning etc?
Answer: The feature lists between the two protocols don’t match exactly. The point of this presentation was to point out that iSCSI is closing the performance gap and has enough high-end features to make it enterprise-ready.
Question: How strong is the possibility that 40G Ethernet will be bypassed, with a move directly from 10G to 100G?
Answer: Vendors are shipping products today that support 40Gb Ethernet so it seems clear that there will be a 40GbE. Time will tell if customers bypass 40GbE and wait for 100GbE.

Thanks again for checking out our blog. We hope to have you on our next webinar live, but if not, we’ll be updating this blog frequently.

Gary Gumanow – iSCSI SIG Co-chairman, ESF Marketing Chair

The white paper "Two May be Better than One: Why Hard Disk Drives and Flash Belong Together" has been posted at http://www.snia.org/forums/sssi/knowledge/education/.  The paper discusses the use of both solid state storage and HDDs in the same system.  Specific mention is made of Paired Storage, a configuration where a small SSD allows fast boot up and quick access to frequently used files and the HDD provides high capacity at a low cost per GB.

The leading storage network technology for mission critical applications today is Fibre Channel (FC). Fibre Channel is a highly reliable and high performing network technology for block storage applications. But, for organizations that can’t afford single purpose networks or the added complexity of managing more than one network technology, FC may not be ideal. With the introduction of Fibre Channel over Ethernet (FCoE), the ability to deploy your FC storage resources over a shared Ethernet network is now possible. But, FCoE isn’t the only available option for block storage over Ethernet.

Initially used primarily by small and medium sized businesses or for less demanding applications, iSCSI is now finding broad application by larger enterprises for mission critical applications. Some of the drivers for increased iSCSI adoption in the enterprise include lower cost for 10Gb Ethernet components as well as the drive toward cloud based infrastructures which benefit from increased flexibility and scalability associated with IP network protocols.

On February 24^th, the SNIA Ethrnet Storage Forum will present a live webcast to discuss the advantages of iSCSI storage for business applications and will show test results demonstrating the performance of SQL Server deployed with 10GbE iSCSI. Hosted by Gary Gumanow, co-chair of the iSCSI SIG and ESF board member, this presentation will include content experts from Emulex and NetApp along with a live Q&A.

Guest Speakers

Steve Abbott – Sr. Product Marketing Manager, Emulex

Wei Liu – Microsoft Alliance Engineer, NetApp

Data & Time: February 24^th, 11am PT

Register today at http://www.brighttalk.com/webcast/25316

SNIA ESF

The SNIA Ethernet Storage Forum is dedicated to educating the IT community on the advantages and best use of Ethernet storage. This presentation is the first in a series of marketing activities that will primarily focus on data center applications during the calendar year 2011.

The Enterprise Solid State Storage Performance Test Specification v1.0 draft has been posted at http://www.snia.org/publicreview/ and is available for download.  [Update: released specification is now available here.] The Enterprise SSS PTS provides a standard way of measuring the performance of SSDs for Enterprise applications, thus enabling fair comparisons of SSDs from different suppliers. It is anticipated that final release of the Enterprise SSS PTS will occur in April 2011. Work is ongoing in the  SSS Technical Work Group on development of a Client SSS PTS. More information about the SSS PTS can be found at http://www.snia.org/forums/sssi/knowledge/education/.

Every year the Storage Networking Industry Association (SNIA) has a gathering of their members in San Jose to coordinate the work of the various Technical Work Groups, Forums and Initiatives. This year the Symposium will take place January 24th – 27th, 2011 at the Sainte Claire Hotel in San Jose, CA. SNIA opens this Symposium to non-SNIA members who are evaluating membership, so feel free to attend. Please Register for the Symposium if you plan to be there in person.

SNIA Cloud Events

The Cloud Storage Technical Work Group (TWG) kicks off a multi-day face to face session starting at 1:00pm PT on Monday. We will be discussing the submission of CDMI for international standardization and continuing to discuss the scope of the next minor release (1.1) of CDMI. Topics include Federation and NoSQL among others. Bring your own ideas for how to improve CDMI. The full agenda has been posted publicly.

On Wednesday, the Cloud Storage Initiative will give an overview of their activities at a breakfast session starting at 8:30am. Then at noon on Wednesday, be sure and join us for the 2011 Activities Kickoff presentation in the Grande Ballroom. We will be showcasing all of the upcoming activities that you will want to be involved with over the next year. This session will be live streamed if you cannot make it in person. Regardless of whether you will be there in person or remote, please register for this update event (in addition to the Symposium registration above). More information.

Wednesday afternoon is the meeting of the Cloud Storage Initiative from 1-5pm (also in the Grande Ballroom). Be sure and join us and help plan the activities for the upcoming year.

Lastly, on Wednesday night there will be a Birds of Feather (BOF) session on a new group that is forming for the Archive and Preservation in the Cloud.

Whereas with Cloud Backup, the cloud is simply a repository of backup data, with Cloud Archive and Preservation, the Cloud is where the active processes occur that ensure long term retention, preservation and viability of data.
CDMI is uniquely designed to accommodate these needs with the Data System Metadata that it standardizes.
Cloud providers see the ability to offer more than just a best effort storage area with the promise of being the trusted steward of information for the long term.
Additional services such as eDiscovery and automatic format conversion can easily be offloaded to the cloud reducing costs.

Please join us Wednesday evening from 5:30pm – 7:00pm in the Grande Ballroom for a Birds of Feather session to kick off the formation of the CSI Archive/Preservation Special Interest Group (SIG). Light refreshments will be provided. If you would like to participate remotely, please use the following call in information:
Toll Free: 866-244-8528
International:+1-719-457-0816
Passcode: 510843#
Webex: http://snia.webex.com, Meeting Name: Archive and Preservation SIG
Meeting Password: cloud2011

SSSI will be at Storage Visions in Las Vegas on January 4-5.  Our booth will feature a demonstration of Storage Pairing (HDD + SSD) technology, details about the SSS Performance Test Specification, and lots of informative white papers & other literature. For more information about the show, see www.storagevisions.com, and for the latest information about Solid State Storage, visit SSSI in booth #4.

Input from the public review of the v0.9 Performance Test Specification led to a decision to split it into two documents - one focused on enterprise and one focused on client performance tests. The Enterprise PTS is due to be released in March 2011, with the Client PTS coming later in the year. See the press release here.

Check out a new Webcast this week by analysts Jim Handy and Tom Coughlin. When: December 16, 2010 at 9:00AM PT What: Why HDD and Flash Belong Together To attend: http://www.brighttalk.com/webcast/23850  Please be sure to log on and learn from two top industry analysts.