Flash Webcast Q&A

David Fair Leave a comment

Our recent Webcast: Flash – Plan for the Disruption was very well received and well attended. We thank everyone who was able to make the live event. For those of you who couldn’t make it, it’s now available on demand. Check it out here.

There wasn’t enough time to respond to all of the questions during the Webcast, so we have consolidated answers to all of them in this blog post from the presentation team. Feel free to comment and provide your input.

Q. Are you going to cache both read and writes in NetApp FlashCache?
A. Flash Cache is a level 2 Read cache and it is used to accelerate random read operations. NetApp offers an additional capability called Flash Pool which caches both random reads and random overwrites. Both technologies are part of the NetApp Virtual Storage Tier family within the Data ONTAP operating environment.

Q. Is eMLC flash available today?
A. Yes, a number of Flash vendors are shipping eMLC today.

Q. Also can you review the write cycle performance of SLC vs. MLC?
A. Write cycles for SLC are typically around 100,000. With eMLC, write cycles of 30,000 per bit can be achieved.

Q. Has specific analysis been conducted on what applications and relative data can be cached at the server versus at the storage controller (tolerance for latency, user patience, etc.)?
A. This varies but server caching will typically be used for applications with the most hot spots such as databases. If there is a particular requirement for ultra low latency such as in OLTP environments, server caching may be appropriate. Server caching can also yield significant benefit to increase VM density. Generally, server caching will be deployed to accelerate a specific application while storage controller caching will be used to accelerate storage which is shared across multiple applications.
Q. Does the data running over the network storage PDUs or Ethernet Layer2/IP traffic?
A. Ethernet Layer 2 in this demo, thought it could have been scaled to for L3 IP routed traffic.
Q. What is the difference between flash tier and flash cache?
A. A flash tier is persistent storage whereby datasets are pinned to flash technology for some period of time (or permanently). In Automated Storage Tiering, data may be migrated to and from the flash tier based on the temperature of the data. A flash cache, on the other hand is a caching technology in which the most frequently accessed data is copied to flash for data access but then evicted as the data cools down. Data is copied to the flash cache either on the basis of calculated data temperature or on a first-in first-out basis.
Q. Given the large advantages of flash on power (direct), cooling, and DC footprint, why do enterprise data centers not just completely switch out their HDDs? It seems like there is a good ROI even without considering performance. Is it the operational complexities that make this challenging?
A. For many applications, this is not cost justified given the significant price difference of the SSD and HDD devices. Since hot data typically amounts to less than 20% of total data, a small amount of flash can be deployed successfully. In the caching case, this can be around 1%.

NFSv4.1 Webcast Q&A

Alex McDonald Leave a comment

Our recent Webcast: NFSv4.1 – Plan for a Smooth Migration was very well received and well attended. We thank everyone who was able to make the live event. For those of you who couldn’t make it, it’s now available on demand. Check it out here.

There wasn’t enough time to respond to all of the questions during the Webcast, so we have consolidated answers to all of them in this blog post from the presentation team. Feel free to comment and provide your input.

Q. Will NFS 4.2 be any easier to migrate to than 4.1? Would it be worth waiting for?

A. NFSv4.2 is a set of additional functionality that will be easy to take advantage of – if you’re on NFSv4.1. The first move is to NFSv4.1, as it offers a wealth of features over and above NFSv3. Waiting for NFSv4.2 features wouldn’t be advisable; it’s unlikely to be ratified until the end of 2012, and enterprise server solutions and the required downstream client distributions will be a lot further out than that.

Q. Since NFS 4.1 is out, what is the uptake in the industry?

A. There aren’t any global figures, since not all suppliers collect detailed information about protocol usage, and of those that do, many can’t differentiate between NFS versions. Anecdotally, it’s slow. That’s because NFSv4.1 servers (particularly for file-layout) have only been available for less than a year, and the needed Linux client support has only recently made it through to the enterprise distributions.. NFSv4 (as opposed to 4.1) is more widely used; but the only figures I have are anecdotal, and would be misleading.
Q. Are there any network architecture design considerations that need to be taken before implementing NFSv4.1?

A. No. In fact, (if you’re not using pNFS) NFSv4.1 should get you more “bang for your buck” as there’s a reduction in network traffic compared with NFSv3. pNFS requires a different architecture; your storage vendor should be able to assist in the planning.

Q. Clustered servers – you mentioned that vendors had to provide a special server for this… are these enhancements going to be ported into the general linux nfs server stream?

A. I’m not sure to what this refers; perhaps the MDS (metadata server)? Although this server is often shown as a separate box in diagrams for simplicity, that’s not how it is normally implemented. The MDS is normally part of the cluster running on one or more fo the data servers.

Q. If you recommend AD for kerberos, do all of the NFS clients need to be joined to the same AD domain as well? Or only the servers?

A. Any time a client in one domain (or realm) attempts to access a server, the server must be in the same realm as the client, or if it’s in another realm, there must be cross realm trust so that the principal (the client) can be correctly authenticated.

Q. Can you talk about any difficulties in using Active Directory with NFS? Are there changes needed on AD?

A. No changes are needed to AD. It’s relatively straightforward security administration, and storage vendors should be able to provide you with implementation checklists.

Q. What is the impact on clustering and failover by introducing statefulness?

A. Significant! And much better. Recovery is much improved, as the server and client after a failure can attempt to agree on what locks were held, what files were open, what data had been written and so on. It’s a big improvement on NFSv3.

Q. Will it be possible to mount root file systems from NFSV4? Like boot from the SAN that we already have in FC or iSCSI?

A. Yes, that doesn’t change.

Q. Can you explain the reasons why home dir and hpc would benefit with v4.1?

A. Home directories are an easy win; no application (well, at least that you care about) and easily migrated. The same is often true of HPC. For example where the data is transient – served from a store to local disk, computed and crunched, and then sent back to the store – the store could be migrated to NFSv4 and the app later; or the app first and the store later.

Flash Webcast – Are You Ready for the Disruption?

David Fair Leave a comment

There’s no doubt that flash is a game changer. Even a relatively small percentage of flash can drive a significant improvement in peak storage performance. How are you planning for the disruption? Join me and my SNIA colleague, Paul Feresten, for a live Webcast next week, Thursday, September 20th (11:00 a.m. ET, 8:00 am. PT) as we discuss the impact of flash. We’ll take a look at how flash is being deployed in storage systems, key considerations and tradeoffs, performance benefits, trends in non-volatile memory and more. And because it’s live we’ll take your questions on the spot. We hope to see you there. Register now.

NFSv4.1 Webcast-Tuesday, August 28th

Gary Gumanow Leave a comment

NFSv4.1 is a mature and stable protocol with many advantages over NFSv3 in meeting the demands being placed on storage by exploding data growth. Now is the time to plan for a smooth migration. I encourage you to register for our live Webcast   on August 28th at http://www.brighttalk.com/webcast/663/52927.

My colleague, Alex McDonald, and I will review what makes NFSv4.1 ideally suited to a wide range of data center and HPC uses. We’ll discuss how careful planning can result in a migration that does not require modification to applications, and that utilizes existing operational infrastructure in its deployment. You’ll see why you should be evaluating and using NFSv4.1 in 2012. And because it’s live, Alex and I will answer your questions on the spot. We hope to see you there. Here are the details:

Date: Thursday, August 28, 2012
Time: 8:00 am PT / 11:00 am ET / 3:00 pm GMT / 5:00 pm CET
Register: http://www.brighttalk.com/webcast/663/52927
We hope to see you there.

Will Ethernet storage move to 10GBASE-T?

David Fair Leave a comment

10GBASE-T is a technology that runs 10Gb Ethernet over familiar Category 6/6a cables for distances up to 100m and is terminated by the ubiquitous RJ-45 jack. Till now, most datacenter copper cabling has been special Direct Attach cables for distances up to 7m terminated by an SFP+ connector. To work, data center switches need matching SFP+ connectors, meaning new switches are required for any data center making the move from 1GbE to 10GbE. 10GBASE-T is generating a lot of interest in 2012 as the first single-chip implementations at lower power (fanless) and lower cost (competitive with Direct Attach NICs) come to market. A data center manager now has an evolutionary way to incorporate 10GbE that exploits the cabling and switches already in place. The cost savings from preserving existing cabling alone can be tremendous.

But is 10GBASE-T up to the task of carrying storage traffic? The bit-error rate technical tests of 10GBASE-T look promising. 10GBASE-T is meeting the 10-12 BER requirements of all the relevant Ethernet and storage specifications. We expect NAS and iSCSI to move rapidly to take advantage of the deployment cost savings offered by 10GBASE-T. Admins responsible for NAS and iSCSI storage over Ethernet should find 10GBASE-T meets their reliability expectations.

But what about Fibre Channel over Ethernet (FCoE)? Note that storage admins responsible for FC and/or FCoE are among the most risk-adverse people on the planet. They especially need to be confident that any new technology, no matter how compelling its benefits, doesn’t appreciably increase the risk of data loss. For this reason, they are adopting FCoE very slowly, though the economics make FCoE very compelling. So a broad market transition to FCoE over 10GBASE-T is likely to take some time regardless.

Cisco announced in June 2012 a new 5000-series Nexus switch supporting up to 68 ports of “FCoE-ready” 10GBASE-T. Cisco has made the investment to support storage protocols, including FCoE, over 10GBASE-T in this switch and is committed to working with the industry to do the testing to prove its robustness. In fact, some eager end-users are getting ahead of this testing, and, based on results from their own stress tests, moving now to storage over 10GBASE-T deployments, including FCoE.

Every major speed and capabilities transition for Ethernet has engendered skeptics. The transition to running storage protocols over 10GBASE-T is no different. General consensus is that the “jury is out” for FCoE over 10GBASE-T. The interoperability and stress testing to prove reliability isn’t complete. And storage admins will generally want to see reports from multiple deployments before they move. But the long-term prognosis for storage – NAS, iSCSI, and FCoE — over 10GBASE-T is looking very encouraging.

10GbE Answers to Your Questions

Gary Gumanow Leave a comment

Our recent Webcast: 10GbE – Key Trends, Drivers and Predictions was very well received and well attended. We thank everyone who was able to make the live event. For those of you who couldn’t make it, it’s now available on demand. Check it out here.

There wasn’t enough time to respond to all of the questions during the Webcast, so we have consolidated answers to all of them in this blog post from the presentation team.   Feel free to comment and provide your input.

Question: When implementing VDI (1000 to 5000 users) what are best practices for architecting the enterprise storage tier and avoid peak IOPS / Boot storm problems?   How can SSD cache be used to minimize that issue?  

Answer: In the case of boot storms for VDI, one of the challenges is dealing with the individual images that must be loaded and accessed by remote clients at the same time. SSDs can help when deployed either at the host or at the storage layer. And when deduplication is enabled in these instances, then a single image can be loaded in either local or storage SSD cache and therefore it can be served the client much more rapidly. Additional best practices can include using cloning technologies to reduce the space taken up by each virtual desktop.

Question: What are the considerations for 10GbE with LACP etherchannel?

Answer: Link Aggregation Control Protocol (IEEE 802.1AX-2008) is speed agnostic.   No special consideration in required going to 10GbE.

Question: From a percentage point of view what is the current adoption rate of 10G Ethernet in data Centers vs. adoption of 10G FCoE?

Answer: As I mentioned on the webcast, we are at the early stages of adoption for FCoE.   But you can read about multiple successful deployments in case studies on the web sites of Cisco, Intel, and NetApp, to name a few.   The truth is no one knows how much FCoE is actually deployed today.   For example, Intel sells FCoE as a “free” feature of our 10GbE CNAs.   We really have no way of tracking who uses that feature.   FC SAN administrators are an extraordinarily conservative lot, and I think we all expect this to be a long transition.   But the economics of FCoE are compelling and will get even more compelling with 10GBASE-T.   And, as several analysts have noted, as 40GbE becomes more broadly deployed, the performance benefits of FCoE also become quite compelling.

Question: What is the difference between DCBx Baseline 1.01 and IEEE DCBx 802.1 Qaz?

Answer: There are 3 versions of DCBX
– Pre-CEE (also called CIN)
– CEE
– 802.1Qaz

There are differences in TLVs and the ways that they are encoded in all 3 versions.  Pre-CEE and CEE are quite similar in terms of the state machines.  With Qaz, the state machines are quite different — the
notion of symmetric/asymmetric/informational parameters was introduced because of which the way parameters are passed changes.

Question: I’m surprise you would suggest that only 1GBe is OK for VDI??   Do you mean just small campus implementations?   What about multi-location WAN for large enterprise if 1000 to 5000 desktop VMs?

Answer: The reference to 1GbE in the context of VDI was to point out that enterprise applications will also rely on 1GbE in order to reach the desktop. 1GbE has sufficient bandwidth to address VoIP, VDI, etc… as each desktop connects to the central datacenter with 1GbE. We don’t see a use case for 10GbE on any desktop or laptop for the foreseeable future.

Question: When making a strategic bet as a CIO/CTO in future (5-8 years plus) of my datacenter, storage network etc, is there any technical or biz case to keep FC and SAN?   Versus, making move to 10/40GbE path with SSD and FC?   This seems especially with move to Object Based storage and other things you talked about with Big Data and VM?   Seems I need to keep FC/SAN only if vendor with structured data apps requires block storage?

Answer: An answer to this question really requires an understanding of the applications you run, the performance and QOS objectives, and what your future applications look like. 10GbE offers the bandwidth and feature set to address the majority of application requirements and is flexible enough to support both file and block protocols. If you have existing investment in FC and aren’t ready to eliminate it, you have options to transition to a 10GbE infrastructure with the use of FCoE. FCoE at its core is FCP, so you can connect your existing FC SAN into your new 10GbE infrastructure with CNAs and switches that support both FC and FCoE. This is one of the benefits of FCoE – it offers a great migration path from FC to Ethernet transports. And you don’t have to do it all at once. You can migrate your servers and edge switches and then migrate the rest of your infrastructure later.

Question: Can I effectively emulate or out-perform SAN on FC, by building VLAN network storage architecture based on 10/40GBe, NAS, and use SSD Cache strategically.

Answer: What we’ve seen, and you can see this yourself in the Yahoo case study posted on the Intel website, is that you can get to line rate with FCoE.   So 10GbE outperforms 8Gbps FC by about 15% in bandwidth.   FC is going to 16 Gbps, but Ethernet is going to 40Gbps.   So you should be able to increasingly outperform FC with FCoE — with or without SSDs.

Question: If I have large legacy investment in FC and SAN, how do cost-effectively migrate to 10 or 40 GBe using NAS?   Does it only have to be greenfield opportunity? Is there better way to build a business case for 10GBe/NAS and what mix should the target architecture look like for large virtualized SAN vs. NAS storage network on IP?

Answer: The combination of 10Gb converged network adapter (CNA) and a top of the rack (TOR) switch that supports both FCoE and native FC allows you to preserve connectivity to your existing FC SAN assets while taking advantage of putting in place a 10Gb access layer that can be used for storage and IP.   By using CNAs and DCB Ethernet switches for your storage and IP access you are also helping to reduce your CAPEX and OPEX (less equipment to buy and manage using a common infrastructure.   You get the added performance (throughput) benefit of 10G FCoE or iSCSI versus 4G or 8G Fibre Channel or 1GbE iSCSI.   For your 40GbE core switches so you have t greater scalability to address future growth in your data center.

Question: If I want to build an Active-Active multi-Petabyte storage network over WAN with two datacenters 1000 miles apart to primarily support Big Data analytics,   why would I want to (..or not) do this over 10/40GBe / NAS vs.   FC on SAN?   Does SAN vs. NAS really enter into the issue?   If I got mostly file-based demand vs. block is there a tech or biz case to keep SAN ?

Answer: You’re right, SAN or NAS doesn’t really enter into the issue for the WAN part; bandwidth does for the amount of Big Data that will need to be moved, and will be the key component in building active/active datacenters. (Note that at that distance, latency will be significant and unavoidable; applications will experience significant delay if they’re at site A and their data is at site B.)

Inside the data center, the choice is driven by application protocols. If you’re primarily delivering file-based space, then a FC SAN is probably a luxury and the small amount of block-based demand can be delivered over iSCSI with equal performance. With a 40GbE backbone and 10GbE to application servers, there’s no downside to dropping your FC SAN.

Question: Are you familiar with VMware and CISCO plans to introduce a Beat for virtualized GPU Appliance (aka think Nivdia hardware GPUs) for heavy duty 3D visualization apps on VDI?  No longer needing expensive 3D workstations like RISC based SGI desktops. If so, when dealing with these heavy duty apps what are your concerns for network and storage network?

Answer: I’m afraid I’m not familiar with these plans.   But clearly moving graphics processing from the client to the server will add increasing load to the network.   It’s hard to be specific without a defined system architecture and workload.   However, I think the generic remarks Jason made about VDI and how NVM storage can help with peak loads like boot storms apply here as well, though you probably can’t use the trick of assuming multiple users will have a common image they’re trying to access.

Question: How do I get a copy of your slides from today?   PDF?

Answer: A PDF of the Webcast slides is available at the SNIA-ESF Website at: http://www.snia.org/sites/default/files/SNIA_ESF_10GbE_Webcast_Final_Slides.pdf  

10GbE – Are You Ready?

Jason Blosil Leave a comment

Is 10GbE coming of age? Many of us within the SNIA-ESF think so. We have co-authored a new and objective white paper on the subject, “10GbE – Comes of Age.” You can download it at http://snia.org/sites/default/files/10GbElookto40GbE_Final.pdf

In this paper we dive deep into why we believe 2012 is the year for wide 10GbE adoption. There are numerous technical and economic justifications that will compel organizations to take advantage of the significant benefits 10GbE delivers. From virtualization and network convergence, to the general availability of LOM and 10GBASE-T there is no shortage of disruptive technologies converging to drive this protocol forward.

This paper is the foundation for much of our activity for the rest of the year. Our 10GbE live Webcast a couple of weeks ago was very well received. In fact hundreds of people either attended the live event or have viewed it on demand. I encourage you to check it out at http://www.brighttalk.com/webcast/663/50385. We also have two more Webcasts scheduled, one on NFS in August and the other on Flash technology in September. Keep checking this blog for details.

This paper is the result of a collaboration of industry leaders from Broadcom, Dell, Emulex, Intel, and  NetApp. We pride ourselves on keeping things “vendor-neutral.” If you’re in IT, we hope you find this cooperation refreshing. If you’re a vendor, we welcome your participation and urge you to consider joining SNIA and the ESF. Get more info on joining SNIA at http://www.snia.org/member_com/join

Live Webcast: 10GbE – Key Trends, Drivers and Predictions

Jason Blosil Leave a comment

The SNIA Ethernet Storage Forum (ESF) will be presenting a live Webcast on 10GbE on Thursday, July 19th.   Together with my SNIA colleagues, David Fair and Gary Gumanow, we’ll be discussing the technical and economic justifications that will likely make 2012 the “breakout year” for 10GbE.  We’ll cover the disruptive technologies moving this protocol forward and highlight the real-world benefits early adopters are seeing. I hope you will join us!

The Webacast will begin at 8:00 a.m. PT/11:00 a.m. ET. Register Now: http://www.brighttalk.com/webcast/663/50385

This event is live, so please come armed with your questions. We’ll answer as many as we can on the spot and include the full Q&A here in a SNIA ESF blog post.

We look forward to seeing you on the 19th!

Impressions from Cisco Live 2012

Jason Blosil Leave a comment

I recently attended Cisco Live in San Diego last week and wanted to share some of my impressions of the show.

First of all, the weather was a disappointment. I’m a native Californian (the northern state of course) and I was looking forward to some sweet weather instead of the cool overcast climate. It’s been so nice in Boston, I have been spoiled.

Attendance was huge. I heard something north of 17,000 attendees. I don’t know if that was actual attendees or registrations. But, it was a significant number and I had several engaging conversations about data center trends, applications, as well as general storage inquiries with the attendees.

Presenting at the Intel Booth

My buddies at Intel asked to make a couple of presentations at their booth and I spoke on the current status of 10GbE adoption and the value it offers. My two presentations were in the morning of the first two full days of the show. Things didn’t look good when only a few attendees were seated at the time we were about to start. My first impression seeing the empty seats in the theater was, “the Intel employees better make a great audience.”

Fortunately, the 20 or so seats filled just as I started with more visitors standing in the back and side. The number of attendees doubled the second day, so maybe I built a reputation.   Yeah, right.

Anyway, let me share just a couple of the ideas from my presentation here:

1)           10GbE is an ideal network infrastructure that offers great flexibility and performance with the ability to support a variety of workloads and applications. For storage, both block and file based protocols are supported which is ideal for today’s highly virtualized infrastructures.

2)           The ability to consolidate data traffic over a shared network promises significant capital and operational benefits for organizations currently supporting data centers with mixed network technologies. These benefits include fewer ports, cables, and components which mean less equipment to purchase, manage, power and cool. Goodness all around.

3)           There are a couple of applications in particular that are making 10GbE particularly useful.

  1. Virtualization – high VM density drives increase bandwidth requirements from server to storage
  2. Flash / SSD – flash memory drives increased performance at both the server and storage which requires increased bandwidth

After the presentation, I asked for questions and was pleased with the number and quality of questions. Sure, we were giving away swag (Intel t-shirts). But, the relevance of the questions was particularly interesting. Many customers were considering deploying converged networks or just moving to Ethernet from Fibre Channel infrastructures. Some of the questions included, where would you position iSCSI vs FCoE? What are the ideal use cases for each? When do you expect to see 40GbE or 100GbE and for what applications? What about other network technologies, such as Infiniband?

Interestingly, very few if any were planning to move to 16Gb Fibre Channel. Now, this was a Cisco show, so I would expect attendees to be there because they favor Cisco’s message and technology or are in the process of evaluating it. So, given Cisco’s strength and investment in 10GbE, it shouldn’t be a surprise that most attendees at the show, or at least my presentation, were leaning that direction. But, I didn’t expect it to be so one sided.

Conclusion

Interest in vendor technology shows is clearly surpassing other industry events, and Cisco Live is no exception. And each Cisco Live event continues to reflect greater interest from customers in 10GbE in the datacenter.

SNIA ESF Sponsored Webinar on Advances in NFSv4

Jason Blosil Leave a comment

Good news.

The SNIA Ethernet Storage Forum (ESF) will be presenting a live webinar on the topic of NFS version 4, including version 4.1 (RFC 5661) as well as a glimpse of what is being considered for version 4.2. The expert on the topic will be Alex McDonald, SNIA NFS SIG co-chair. Gary Gumanow, ESF Board Member will moderate the webinar.

The webinar will begin at 8am PT / 11am ET. You can register for this BrightTalk hosted event here http://www.brighttalk.com/webcast/663/41389.

The webinar will be interactive, so feel free to ask questions of the guest speaker. Questions will be addressed live during the webinar. Answers to questions not addressed during the webinar will be included with answers from the webinar on a blog post after the event on the SNIA ESF blog.

So, get registered. We’ll see you on the 29th.