|
|
| . |
and related articles
military SSDs
the SSD reliability
papers
this
way to the Petabyte SSD
Surviving SSD
sudden power loss
how fast can your SSD
run backwards?
the Survivor's
Guide to Enterprise SSDs
Data Integrity
Challenges in flash SSD Design
Efficiency - making the
same SSD - but with less chips
|
Kaminario drops PCIe and
turns to SAS to get costs down in new HA rackmount
Editor:- April
18, 2013 - "You don't have to be an investment bank like JP Morgan to
afford our style of fast, scalable high availability SSD systems any more"
- was the key message I got talking to Phil Williams,
VP Business Development at Kaminario earlier
this week when discussing with me aspects of the company's newest series of
FC SAN compatible SSD
arrays - the
K2 v4 which was
launched
yesterday.
Phil was referring to the expectation that their products -
which in the first generation were entirely
RAM based SSDs - and
then moved onto RAM / flash hybrids and then mostly pure flash (the flash
components being implemented in the previous generation of K2's by
Fusion-io's PCIe SSDs
- a relationship direction which I suggested in a much earlier briefing
conversation with Kaminario's CEO few years ago BTW ) - had acquired a
reputation of being out of reach pricewise - and not just in a class of their
own for resilience and
scalability.
One
of the ways that Kaminario has pulled off the affordability trick is to drop
PCIe SSDs as the internal flash components and use instead
SAS SSDs.
I've
said before that in the enterprise arrays space - "SAS is the new SATA"
- because there are so many companies which have moved into this segment
that there's stiff competition. Unlike the PCIe SSD market -which is mostly sold
on high performance - the SAS market includes a number of vendors who have been
using adaptive
R/W ECC to enable them to use cheap flash to build reliable
fast-enough SSDs
Because Kaminario still has a lot of
RAM cache in
its server based architecture - it doesn't need the raw
endurance
and performance of
FIO's ioMemory to deliver multi-gigabyte throughput at the rack level. And
another factor is that Fusion-io itself is on course to become a significant
supplier of rackmount SSDs (although not aimed at the same kind of customers.)
Kaminario didn't want to say which SAS product they're using. They
might say later. But it doesn't really matter.
The K2 v4 also
demonstrates that the key IP component in Kaminario's box is SSD software.
When I suggested that future boxes could equally well discard SAS SSDs if
2.5" PCIe SSDs
offered a better set of characteristics - Phil agreed that the company wasn't
tied to any particular internal SSD drive form factor or interface.
Kaminario
has paid Taneja Group
to do some new testing on the performance aspects of simulated hard faults.
These will be very useful for customers - and take the uncertainty out of the
picture - giving hard numbers for various scenarios.
For example - when
running at just under 200K
IOPS and
5GB/s throughput - an entire node (controller) was removed to simulate a fault.
I/O resumed after 23 seconds and performance dropped by less than 15% for 2
minutes before recovering fully.
Virident betas remote PCIe SSD sharing
Editor:-
February 21, 2013 - Virident
Systems recently
announced
beta availability of a new software suite - called FlashMAX Connect - which
enables low latency shared server-side storage and
high availability
when used with the
company's range of PCIe SSDs.
New functionality includes:-
- fast / low-latency synchronous mirroring that replicates writes from one
server to another, providing storage node or server failover without affecting
application and data availability.
- shared storage management in remote PCIe SSDs. This allows customers to
share the storage residing on remote servers and thereby scale PCIe flash
capacity independent of compute. For example - a single PCIe flash card can
service multiple servers.
IBM paper on SSD's data challenges
Editor:- December
4, 2012 - I've been browsing the
online
papers from last week's Server
Design Summit.
If you can only read one - it should be this:-
How
do we handle all the data? (pdf) - by Andy Walls, Distinguished
Engineer, Storage Hardware Chief Architect, IBM.
I won't give
away the plot - because I think you'll enjoy it more if you read it yourself.
But here are a few bullet points which resonated with me.
Among other
things - Andy Walls says...
- "90% of all the data in the world today was created in the last 2
years."
- "Flash is starting to free up the IO bottleneck - but the bottleneck
is more complicated..."
...read
the article (pdf)
See also:-
future SSD capacity
ratios , SSD
bottlenecks, where
are we now with SSD software?
OCZ's new VXL software release includes fault tolerant support
for arrays of PCIe SSDs
Editor:- October 23, 2012 - OCZ today
released
a new version (1.2 ) of its
VXL
cache and virtualization software - which provides high availability,
synchonous replication and enhanced VM performance across arrays of the
company's Z-Drive R4 PCIe
SSDs.
HA Support in Fusion-io's ION SAN kit
Editor:- August
2, 2012 - Yesterday - Fusion-io
launched
its new ION software
- which is a toolkit for bulding your own network compatible
SSD rack by
adding some Fusion-io SSD cards and their new software to any leading server.
The concept isn't entirely new - because oems have been doing this
with various different brands of
PCIe SSDs for years
and this is a well
established alternative market segment for PCIe SSDs. What is new - is
that it makes the whole thing much easier.
Fusion-io says this new
software product "delivers breakthrough performance over
Fibre Channel,
InfiniBand and
iSCSI using standard
protocols." (1 million random IOPs (4kB), 6GB/s throughput and 60
microseconds latency in a 1U rack.)
It also supports fault tolerance
between racks.
HA support in OCZ's PCIe SSD software
Editor:- July
3, 2012 - OCZ
published a white paper today -
Accelerating
MS SQL Server 2012 with OCZ Flash Virtualization (pdf) which describes
the performance of the company's
PCIe SSDs (Z-Drive R4)
and its
VXL
caching and virtualization software in this kind of environment.
The
interesting angle (for me) was in the aspect of
SSD fault
tolerance rather than the 16x VM speedup.
The paper's
author Allon Cohen
(who has written many thought provoking
performance blogs)
explains in this paper - "VXL software has a unique storage virtualization
feature-set that enables transparent mirroring of SQL Server logs between 2
flash cards, thereby assuring that the log files can be accessed with ultra high
performance, while at the same time, are highly available for recovery if
required." ...read
the article (pdf)
SSD FITs & reliability
Editor:- June 20, 2012
-the component level isn't always the best level of abstraction in modeling
enterprise SSD reliability.
Extrapolating from the single SSD
component level can give you a misleading idea - because SSDs are data
architecture components.
A
recent article on my SSD news
page on this subject started with an email from a reader who knew a lot more
about SSD component reliability than me.
GridIron's SSDs can serve hundreds of concurrent databases
effectively
Editor:- May 30, 2012 - GridIron Systems
describes the setup required to exceed 1 million (4kB) IOPS in a 40x MySQL
environment with mirroring - all in a single cabinet (including servers) using
its FlashCube
SSD systems (upto 80TB in this configuration), and some 10GbE and 16GbFC
fabric switches in a new
whitepaper
(pdf)
published
today.
"In large-scale MySQL environments it's not uncommon to see
hundreds or even thousands of database servers," said Dennis Martin,
President of Demartek
(which tested this configuration). "This reference architecture opens a
new, more efficient architectural approach for serving increasing numbers of
users and database queries per cabinet."
Pure Storage unveils new HA deduped array
Editor:-
May 16, 2012 - Pure
Storage today
unveiled
a new generation of fast-enough
(100K write IOPS)
HA/FT SSD arrays
today - with upto 100TB compressed capacity - which are clustered around
InfiniBand.
new article on Enterprise SSD Array Reliability
Editor:-
March 1, 2012 - Objective Analysis
has published an article -Enterprise
Reliability, Solid State Speed (pdf) - which examines the conflicts which
arise from wanting to use SSD for enterprise acceleration - while also
preserving data protection in the event of SSD failure.
New approaches
and architectures are required - because traditional methods can negatively
impact performance - or - as in the case of RAID - don't always work.
"RAID is configured for
HDDs that fail
infrequently and randomly. SSDs
fail rarely as well, but fail predictably" says the author Jim Handy -
who warns that "SSDs in the same RAID and given similar workloads can be
expected to wear
out at about the same time."
He examines in detail one of the
many new aproaches to high availability enterprise SSD design - that's used in
Kaminario's
K2.
...read
the article (pdf)
See also:-
the SSD reliability
papers, storage
reliability, high
availability enterprise SSD directory and
SSD market analysts.
TMS packs 24TB fastest HA eMLC in 1U
Editor:-
February 28, 2012 - I was just getting used to getting the measure of how much
enterprise flash capacity can fit into 1U rackspace - when Texas Memory Systems
changed things yet again by doing even more.
TMS today
announced a 24TB
high availability
system called the
RamSan-820.
This has similar internal architecture to their 720 which
I discussed with
their CEO Holly Frost last December - but it uses
eMLC instead of
SLC - hence the doubling of the storage density.
TMS today revealed
more about the internal features of their proprietary rackmount SSDs. Their
RamSan-OS has been in continuous development for over 5 years, initially
shipping with the RamSan-500
flash SSD in 2007.
The RamSan-OS is designed from the ground up to run on a cluster of CPU
nodes and FPGAs distributed throughout the RamSan systems.
Speed
is still a core differentiator from TMS.
"Many of our competitors
claim they are software companies and that their products are Application
Accelerators. While this may be fundamentally true, all TMS products are 2x
faster than any other Application Accelerators shipping today,"
according to TMS CEO Holly Frost. "It comes down to very simple
technical and business questions: Why put key functions into slow software when
you can speed up these functions in fast hardware?"
Power
consumption is an important part of the
reliability budget
- and to drive this point home TMS say they are happy to supply customers with
a wattmeter so they can compare these new SSDs with competing products.
Nimbus does that "no spof SSD" thing
Editor:-
January 31, 2012 - Nimbus
Data Systems today
announced
its entry into the
high availability
enterprise SSD market with the uveiling of the company's -
E-Class systems -
which are 2U rackmount SSDs with 10TB
eMLC per U of
usable capacity and no single point of failure. Unified interface
support includes 10GbE,
FC, and
Infiniband.
Nimbus
software (which supports upto 0.5
petabytes in a
single SSD file system) automatically detects controller and path failures,
providing non-disruptive failover. The E-Class also supports online software
updates and online capacity expansion. It has
RAID protection and
hot-swappable flash, power, and cooling modules. Pricing starts at $150K approx
for a 10TB dual configuration system.
Editor's comments:-
Nimbus seemed incredulous at my immediate reaction to the preliminary info they
sent me. I said I knew of competing shipping SSDs which were denser, faster
and offered more HA features too. But that's not to understate the value of
what the company does. Instead of being impressed by a bunch of me-too
technical metricals I was rather more impressed to learn that Nimbus is still
profitable. More about that later.
HA enterprise SSD arrays
Editor:- January 26, 2012 -
due to the growing number of oems in the high availability rackmount SSD market
StorageSearch.com today
published a new directory focusing on
HA enterprise SSD
arrays.
The new directory will make it easier for users to locate
specialist HA SSD vendors, related news and articles.
If you're a
marketer in an SSD company, not listed in the preliminary vendor listing on this
page below, and you haven't contacted me in the past few weeks about your HA
SSD systems - then contact
me with details.
Huawei Symantec publishes SPC-1 results for Dorado2100 SSD
Editor:-
January 12, 2012 - Huawei
Symantec has published an
SPC
Benchmark report (66 pages pdf) for its high availability FC SAN rackmount
SSD - the
Oceanspace
Dorado2100.
A 1 terabyte (approx) usable protected (mirrored) SSD
system (2.4TB raw) delivered over 100K SPC-1 IOPS at a market price of$0.90/SPC-1
IOPS. Click
here for summary (pdf)
Editor's comments:- these
SPC
reports are very technical and the $ per SPC-1 IOPS headline
figures include a lot of detailed factors including 3 years of 4 hour on-site
response warranty etc. But the documents also include market prices for
everything which goes into these calculations. From which we learn that a
2.4TB Dorado2100 SSD system with 16x 8Gbps FC ports costs about $52,000. See
also:- SSD pricing
will new RamSan rattle Violin?
Editor:- December 6,
2011 -
Texas Memory Systems today
announced
imminent availability of the
RamSan-720
- a 4 port (FC/IB) 1U
rackmount SSD
which provides 10TB of usable 2D (FPGA implemented)
RAID protected and hot
swappable - SLC
capacity with 100/25 microseconds R/W latency (with all protections in
place) delivering 400K IOPS (4KB), 5GB/s throughput - with no single point of
failure (at $20K/TB approx list).
The new SSD uses a
regular RAM cache
flash architecture which in the event of
sudden power
loss has an ultra reliable battery array which holds up the SSD power for 30
seconds while automatically backing
up all data in flight and translation tables to nonvolatile flash storage. On
power up - the SSD is ready for full speed operation in less than a minute.
Aimed
at HA tier 1 storage markets - the RamSan-720 consumes only 300-400 W - which
makes it practical for high end users to install nearly 1/2
petabyte of SSD
storage in a single cabinet - without having to worry about the secondary
reliability and
data integrity
risks which can arise from high temperature build-ups in such
enclosures.
Editor's comments:- I've
been talking to TMS every month for over 10 years - and I've been writing
about their memory appliances since the early 1990s - so you might think that I
would have run out of things to say by now. When I saw the preliminary specs
for the new RS-720 - the features which jumped out at me were:-
- the low R/W latency for this class of SPOF product. Which is 2x as
good as the next fastest product I know - the 6000 series fron
Violin - and several
times faster than some other tier 1 SSD vendors such as
Kaminario and
Huawei Symantec
- the high storage density - over 3x better than
Violin delivers in SLC -
and close to the usable RAIDed capacity that a
Fusion-io 1U server
can deliver in MLC when using Octal.
A few days ago I spoke to
Holly Frost, CEO
and Dan Scheel,
President of Texas Memory Systems about their new SSD, what they think about
what's going on in the SSD market, and the philosophy that steers the design
of their SSDs. In a hour long discussion I learned enough new stuff to write
several new articles. So instead of condensing it down here into a couple of
bullet points - I'm going to give you the benefit of what I learned in a
new article tomorrow called -
"StorageSearch
talks SSD with Holly Frost."
Going back to my headline - will
new RamSan rattle Violin?
I'm sure that Violin would say that this
simply validates what they are doing (and shipping) already - and that the
enterprise SSD market is big enough for all vendors in this category to
keep growing
at a healthy clip. It make you wonder how much a company like TMS might be worth
too...
Violin unveils naked cost advantages in reliable SSD arrays
Editor:-
September 27, 2011 -
Violin Memory
today announced
new models and options in its range of fast
iSCSI /
FC SAN rackmount SSDs.
The new
6000
series - designed for high availability applications with no single point
of failure and hot swappable "everything" - provides 12TB SLC, or
22TB MLC usable capacity with 200/600 microseconds mixed latency, 1 million /
500K sustained RAIDed spike free write IOPS, in 3U rackspace at a list price
around $37K / $20K per terabyte.
For less demanding applications (but
still featuring hot swap memory modules) the company has also extended its
lower priced
3000 series
to 16TB SLC usable capacity.
Editor's comments:- when I spoke
to Violin's CEO -
Don
Basile about the new 6000 series he was curious about how I would tell
you what's unique about this product and signal whether it's relevant to you or
not.
I said - when it comes to reliability -
you've either got it - or you haven't - and there aren't too many enterprise
SSD systems which have hot-swap everything. That's one of the reasons the
latency looks slow - compared to many other fast SSDs - because the figures
quoted here include the latency of the internal factory built protection
schemes.
Another angle - I said is your product is an example of
"big SSD
architecture". When I explained what I meant - Don agreed and said
what it means for the customer is
lower price.
Because when you look at the raw capacity that's lost to over-provisioning
and RAID like protection
and get down to the usable capacity that the customer sees in an MLC rack - say
- then Violin's 6000 delivers about 70% of the raw capacity - versus nearer to
30% in an array of 2.5"
SSDs for example. That confers a 2 to 1 native cost and density
(SSD TB/U) advantage.
I said Violin's density looks good too - compared
say to Kaminario's K2.
I
also said - that our SSD readers would recognize what was meant by "spike-free"
IOPS - because of various
past articles
about this - and because another enterprise flash vendor -
Virident Systems -
had made that one of the
differences they
talk about compared to some other flash
PCIe SSD companies. I
knew that in Violin's case that was due to their patented non-blocking write
architecture - which was explained to me when their
first flash
products came to market in 2008.
Don said - that inside their
protection array they're actually doing 5x more IOPS than the customer
is seeing outside the box and on the datasheet - and that helps too.
I
also asked about price - and where they were relative to $30K / TB - which is
the ballpark for this type of product - and you can see where Violin are above.
That's a competitive figure for a no SPOF SSD.
I said that for people
who are serious about enterprise SSDs it's relatively easy to decide what
products you may want to focus in on after just seeing a couple of simple
metrics.
Don did also mention a comparative write up - about their
SSD versus another so called "tier 1" storage solution - from
EMC. Violin think it
makes them look pretty good - but I can't understand why anyone cares how they
stack up to EMC - who never understood the SSD plot - which is why their (at
one time) prime SSD supplier
STEC has had a bumpy
revenue stream in recent years.
I had one final question for Don -
which wasn't about Violin's new SSD - but about
something
which had come to my attention while I was googling the company just before
our conversation.
When can we expect to see a picture of a naked man
featured on a
Vmem
poster ad? - I asked.
He laughed and indicated it wouldn't be
anytime soon. | |
| . |
|
| . |
| ... |
| |
... |
| "Back in 2003 all
enterprise acceleration SSDs were RAM SSDs. Now 99% of enterprise SSDs are
flash. But what kind of flash? That has changed too..." |
| sugaring flash for
the enterprise | | |
| ... |
| How are fault tolerant
PCIe SSD designs supported at the chip level? |
| PCIe in
enterprise SSD designs - this video by PLX includes an
introductory tutorial into PCIe and its performance and architectural
capabilities for SSDs including automatic failover and multi-host capabilities. |
| PLX's switch chips also supports failover if
the fault occurs in the PCIe switch fabric chips themselves. |
... |
|
extract - "...And in case one of the hosts fails
and you want to connect the SSDs - or the devices connected to that host - to
another host - that can be done automatically as well - and the surviving host
can attach the devices that were attached to the failing host to itself and
control it so that the system doesn't go down and the data stored in these
devices doesn't get isolated from the main system." | | | |
| ... |
|
|
| ... |
| a new
market for factory configured HA / FT SSDs |
by
Zsolt Kerekes ,
editor - January 26,
2012
It's always been relatively easy for users and
systems integrators to configure high availability rackmount SSD systems by
using failover and clustering techniques designed for traditional
FC SAN or
IP SAN storage systems -
so you may ask - why have a different directory page which is focused on factory
designed HA SSDs?
The answer is:-
fault symmetry
(performance in the failed vs unfailed state), ease of use, risk, complexity,
and scalability.
Customer designed fault tolerant wrap arounds
inevitably go outside the SSD
controller loop. And because they simply engage data at the host
interface level they incur considerable losses in latency and failure recovery
time compared to systems where the HA fault tolerant architecture has been
designed inside the SSD system - behind the host interface and around the SSD
memory arrays. And customized HA SSD designs can introduce software
complexities and controller configuration issues - because even if the native
SSD systems look like virtual storage - the FT wraparound introduces its own
peculiar characteristics.
Anyone who has done a formal hazard
analysis or failure analysis in a critical industry knows that it's all too
easy to think that a particular FT problem has been solved whereas in fact
there are still common modes of failure.
One of the invisible risks of
"configure your own" HA arrays is that the user may incur the cost of
assembling a DIY HA configuration only to discover that when a fault does occur
- their solution became part of the problem instead of solving it. That's
another reason that factory designed HA SSDs are superior. They reduce risk -
due to the fact that they have been designed by people who spent more time
thinking about the problems than you can afford to do yourself.
Vendors
I've spoken to in the HA SSD market are excited that their products will open up
new businesses - but a particular concern - first voiced to me in November 2011
by
Don
Basile, CEO of Violin
was that HA SSDs could just get lost amidst a sea of other SSD announcements.
And if you're reading through a bunch of pages which talk about
SSD performance and
see some latency and performance figures for an HA SSD in the wrong context -
you may well think - that's doesn't sound so great - whereas in the context of a
protected performance metric - it may instead be truly amazing.
In my
past 20 years of publishing enterprise buyers guides - I've developed an
instrinct for judging when the market is ready for a new focused directory.
Sometimes I've been too early - but with the memontum in the SSD market and the
number of HA SSD vendors dipping into double digits - I think this is
exactly the right time for a new directory. | | |
| . |
 |
| . |
 |
|
|
|
|
| . |
|
| |
