Data centers that use centralized storage, SANs or NAS, sometimes use servers to cache stored data and thus accelerate the average speed of storage. These caching servers sit on the network between the compute servers and storage, using a program called memcached to replicate a portion of the data stored in the data center’s centralized storage. Under this form of management more-frequently-used data presents itself faster since it has been copied into a very large DRAM in the memcached server.
Such systems have been offset over the past five or more years thanks to the growing availability of high-speed enterprise SSDs at an affordable price. Often direct-attached storage (DAS) in the form of an SSD within each server can be used to accelerate throughput. This can provide a considerable cost/performance benefit over the memcached approach since DRAM costs about 20 times as much as the flash in an SSD. Even though the DRAM chips within the memcached server run about three orders of magnitude faster than a flash SSD most of that speed is lost because the DRAM communicates over a slow LAN, so the DAS SSD’s performance is comparable to that of the memcached appliance.
There’ a catch to this approach, since the DAS SSD must be Continue reading “A New Spin on Memcache”
Kaminario recently decided to adopt a “software-centric” business model, rather than sell all-flash arrays as the company has done since its inception. The company says that this will allow it “to streamline operations, while focusing its resources on continued software innovation,” acknowledging that the change: “represents a strategic business model shift for Kaminario.”
Hardware support for existing and future Kaminario customers will be provided by Tech Data, which Kaminario’s release tells us is the world-leading end-to-end distributor of technology products, services, and solutions.
Jay Kramer of Network Storage Advisors, a friend of The SSD Guy recently provided me with some valuable insights on Kaminario’s restructuring and has allowed me to share them here. Jay is a recognized technology consultant specializing in the network storage industry.
Here’s what Jay has to say Continue reading “Kaminario Adopts Software-Only Business Model”
This post is the second of a two-part SSD Guy series outlining the nonvolatile DIMM or NVDIMM. The first part explained what an NVDIMM is and how they are named. This second part describes the software used to support NVDIMMs (BIOS, operating system, and processor instructions) and discusses issues of security.
Today’s standard software boots a computer under the assumption that the memory at boot-up contains random bits — this needed to be changed to support NVDIMMs. The most fundamental of these changes was to the BIOS (Basic I/O Subsystem), the code that “wakes up” the computer.
The BIOS is responsible for detecting all of the computer’s hardware and installing the appropriate drivers, after which it loads the bootstrap program from the mass storage device into the DRAM main memory. When an NVDIMM is used the BIOS must Continue reading “An NVDIMM Primer (Part 2 of 2)”
NVDIMMs are gaining interest lately, so The SSD Guy thought it might be worthwhile to explain both what they are and how NVDIMM nomenclature works.
As I was writing it I noticed that the post got pretty long, so I have split it into two parts. The first part explains what an NVDIMM is and defines the names for today’s three kinds of NVDIMM. The second part tells about software changes used to support NVDIMMs in BIOS, operating systems, and even processor instruction sets. It also discusses the problem of security.
In case the name is unfamiliar, NVDIMM stands for “Nonvolatile Dual-Inline Memory Module.” Standard computer memory – DRAM – is inserted into the system in the DIMM form factor, but DRAM loses its data when power is removed. The NVDIMM is nonvolatile, or persistent, so its data remains intact despite a loss of power. This takes some effort and always costs more for reasons that will be explained shortly.
Although might seem a little odd to discuss memory in a forum devoted to SSDs, which are clearly storage, the NVDIMM is a storage device, so it rightly Continue reading “An NVDIMM Primer (Part 1 of 2)”
Yesterday IBM unveiled a sweeping update of its existing flash storage products. These updates cover a range of products, including IBM Storwize All Flash arrays: V7000F, V7000 Gen2+, and V5030F, the FlashSystem V9000, the IBM SAN Volume Controller (SVC), and IBM’s Spectrum Virtualize Software.
The company referred to this effort as a part of a: “Drumbeat of flash storage announcements.” IBM has a stated goal of providing its clients with: “The right flash for the right performance at the right price.”
IBM’s representatives explained that the updates were made possible by the fact that the prices of flash components have been dropping at a rapid pace while reliability is on the rise. The SSD Guy couldn’t agree more.
Here’s what IBM announced:
Starting from the low end and moving up, the V5030F entry-level/midrange array is an Continue reading “IBM Refreshes Broad Swath of Flash Offerings”
A recent conversation with some fellow analysts revealed a puzzling set of claims. EMC, at its EMC World conference (May 3-7) claimed to be the leader in flash array shipments. The very next week, in the same Las Vegas hotel, IBM also claimed leadership in flash.
Who do you believe?
Well a friend of The SSD Guy, marketing consultant Jay Kramer of Network Storage Advisors Inc., tallied up all of the leadership claims he could find and provided this list:
- EMC is counting XtremIO Arrays as units shipped and according to Gartner Group held the #1 market share position with a 31.1% share, which is over a ten percentage point share lead
- IBM is counting capacity of PBs shipped with all of their flash storage solutions: The FlashSystem 840, 900, V840, V9000, DS8000, plus the XIV systems, Storwize V7000, IBM Flash DAS, and IBM PCIe Adapters
- NetApp is the leader if you count total flash systems shipped (NetApp-branded plus privately-branded systems) spanning multiple years as their SANtricity operating system and E-Series platforms have sold over 750,000 units
- Pure Storage uses its 700% growth to show that it’s the #1 fastest-growing flash storage company
- Then, if you want to compare any vendor’s total all flash array (AFA) systems sold this past year against hybrid storage arrays, Nimble Storage beats any of the AFA vendors.
Continue reading “Who’s #1 in Flash Arrays?”
This is an excerpt of an article that was originally posted in the 2/25/15 edition of the Pund-IT Weekly Review
IBM has unveiled its new IBM FlashSystem V9000, an all-new offering that supports scale-up and scale-out flash growth models. The FlashSystem V9000 is an upgrade to the company’s FlashSystem V840 product. IBM also introduced the new IBM FlashSystem 900, the follow-on generation to the IBM FlashSystem 840. A full complement of software services (including snapshots and replication) is bundled with the product.
Over 4,000 IBM FlashSystems have shipped since the brand was introduced two years ago causing the company’s bit shipments to outpace the combined shipments of the second and third-ranked flash array providers.
The IBM FlashSystem V9000 comes in a 6U package that incorporates twelve IBM MicroLatency modules that provide 57TB of RAID 5 usable capacity, which then blooms to 285TB with IBM Real-time Compression. The proprietary modules provide more consistent performance than SSD-based systems – the system is as fast when it is 90% full as it is when only 10% of its total capacity is in use.
IBM tells us that the FlashSystem V9000 is not simply a virtualized node built up from a number of IBM FlashSystem 900 systems, but is a single, integrated system purpose-built to address the needs and focus of cloud, analytics, mobile/social and security. It supports seamless concurrent capacity increases up to its 2.2 petabyte upper limit when real-time compression is used.
IBM’s FlashSystem V9000 is currently available and carries a 7-year warranty as well as an optional 5-year “TCO” lease that IBM has priced to be cheaper than the high-performance disk arrays it has been designed to replace. This is intended to bring peace of mind to skittish would-be flash users.
The SSD Guy has always admired TMS products, and they appear to be getting even better under IBM’s care. Both systems should provide a pretty important boost to IBM’s competitive positioning.
There’s been a lot of interest in NVRAM recently. This technology has been lurking in the background for decades, and suddenly has become very popular.
What is NVRAM? Quite simply, it’s DRAM or SRAM that has a back-up flash memory a small controller, and a battery or super-capacitor. During operation the DRAM or SRAM is used in a system the same way that any DRAM or SRAM would be used. When power is interrupted the controller moves all of the data from the DRAM or SRAM to the flash using the backup power from the battery or super-capacitor. When power is restored, the controller moves the contents of the flash back into the SRAM or DRAM and the processor can resume operation where it left off.
In some ways it’s storage and in some ways it’s memory, so Continue reading “Where does NVRAM Fit?”
I have just added a new white paper onto the Objective Analysis website: Matching Flash to the Processor – Why Multithreading Needs Parallelized Flash.
This document examines the evolution of today’s CPUs, whose clock frequencies have stopped increasing, but now exploit parallelism to scale performance. Multiple DRAM channels have also been added to performance computing to add parallelism to the memory channel.
Storage hasn’t kept pace with this move to parallelism and that is limiting today’s systems.
New NAND flash DIMMs recently introduced by Diablo, SanDisk, and IBM, provide a reasonable approach to adding parallel flash to a system on the its fastest bus – the memory channel. This white paper shows that storage can be scaled to match the processor’s growing performance by adding flash DIMMs to each of the many DRAM buses in a performance server.
The white paper is downloadable for free from the Objective Analysis home page. Have a look.
On Thursday IBM announced its X6 product family, the sixth generation of the company’s successful EXA server architecture. A smaller byline of the introduction was the company’s new eXFlash memory-channel storage or eXFlash DIMM which is offered as one of many flash options available to X6 users.
Close followers of The SSD Guy already know that I am a serious advocate of putting flash onto the memory bus. Why slow the technology down by Continue reading “IBM Launches Flash DIMMs”