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Peeking inside the loop of
ioMemory
Editor:- November 12, 2010 - Fusion-io has said
it
will
ship a web based control panel - called ioSphere - for monitoring,
analyzing real-time
performance and controlling its SSDs sometime in Q1, 2011.
Editor's comments:- Usually when you retrofit software based analysis
and control functions to storage networks there's an impact on performance. As
spinning hard disk media
is very slow compared to spinning electrons - this doesn't matter - especially
when using fast multi-core CPUs.
But when you're talking about
PCIe and
Infiniband SSDs
those precious micro-seconds that a new software agent spends fooling around
with your data-flows can interfere with smooth running. Although SSD
companies have many times in the past announced such functionality for legacy
SAN based SSDs (for
example in
May 2003
-
Imperial Technology
launched the WhatsHot SSD analysis tool) real-time SAN SSD analyzers have
mostly stayed out of the customer's mission critical cabinets and remained
locked in the developer's labs.
Will ioSphere be any different? -
Knowing a bit about the thinking behind Fusion-io's SSD controller architecture
- which I discussed in an
interview with
their CEO in the summer - I anticipated that Fusion-io's ioSphere would be
different. Why? - Because the host server processor is inside the
SSD controller loop
and all the critical control state diagrams are already in the software
stack. So I asked for confirmation about this guess.
Fusion-io's VP of
product and technical marketing, Gary Ornstein, told me - "Your assumption
is correct. There is no overhead. The ioSphere software is providing insight to
information that is already collected within our ioMemory modules"
If
you look at the philosophy of the Fusion-io designs - one view you can take is
that the SSD makes the host CPU work faster - because it speeds up access to
the data. Another view - equally valid - is that because the host CPU is doing
work for the flash memory - the faster the user's CPU - the faster the SSD. And
the converse is true - which is it that the SSD operates slower when it's used
in tandem with a slower host. Yet another way of seeing these roles is that
both the CPU and the SSD are responsible for the speed of running the apps
together - and you can trade CPUs for SSDs - something I used to call
SSD CPU equivalence. It
may be that fusion of function - which led to the company's founders choosing
the name Fusion-io. Next time we talk I'll remember to ask about that.
SSDs as computer medicine?
Editor:- November 11,
2010 - In a new blog
today on StorageSearch.com
I reflect on how concerns about flash SSD endurance have popped up to the
top of readers' interests.
"For SSD users - the risk of flash SSD
wear-out due to ineffective endurance control is like that of influenza. Just
because you've already had it before - or been inoculated against the previous
strain doesn't mean you are invulnerable to what may happen in the next flu /
flash pandemic."
...click to read the
article
How many disks - and why?
Editor:- November 10, 2010
- StorageSearch.com
- today published a new article called -
How many disks does it
take to store a disk-full of data?
Sometimes you can learn
something very useful by asking silly questions which initially seem to
have trivial and obvious answers. ...And where do the SSDs creep in? They always
seem to pop up in my articles somewhere... You don't need a calculator or
spreadsheet for this one. ...read the article
QLogic reports new InfiniBand switch record
Editor:-
November 9, 2010 - QLogic
announced that its
InfiniBand adapters
and switches have achieved cluster message rate performance of over
86
million messages per second - a new
record.
The system configuration was a 14 node cluster with 2
switches.
RunCore launches world's 1st CF card SSD with fast purge
Editor:-
November 9, 2010 -
RunCore has launched
the world's first CF card compatible SSDs with fast (typically 30 seconds)
on-board sanitization
functions.
The fast erase - which is designed to protect confidential
data leaks and thwart any attempts at
data recovery - is
achieved by pressing a button or activating erase pins while the device is
powered. It can be once again used by formatting after the data destruction
process.
Editor's comments:- due to the popularity of the CF
form factor in consumer products many equipment designers have adopted it as a
convenient way of incorporating solid state storage into products in the
industrial, medical and prosumer markets. Without an on-board fast purge feature
- achieving effective
disk sanitization
as a software process in an SSD can take upto 24 hours (depending on disk
capacity). RunCore's industrial CF cards are true SSDs with wear-leveling,
vibration tolerance and low power consumption.
Greenliant samples SATA BGA SSDs
Editor:- November 8,
2010 - Greenliant
Systems has
begun
sampling SATA
compatible variants of its
NANDrive
GLS85LS (miniature
SSDs).
The new SSDs have upto 64GB capacity in a 14mm x 24mm x
1.85mm 145 BGA. Active-mode power consumption as low as 500mW and a deep
power-down mode can reduce this to 10mW. The SSDs have content protection zones
and designers can select areas of the storage to protect with
fast erase.
"OEMs have recognized the benefits of Greenliant's NANDrive in providing
superior reliability,
and the addition of SATA-based NANDrive devices provides our customers with more
options to choose a compatible SSD that best suits their needs for various
market segments and applications," said Bing Yeh, CEO of Greenliant
Systems. "While we are currently sampling our new commercial-grade SATA
NANDrive products, an industrial-grade version is under development."
flash SSDs vs RAM SSDs in ZIL (ZFS) environments
Editor:-
November 8, 2010 -
DDRdrive has
published a white paper which compares
flash SSDs vs RAM SSDs
(pdf) as accelerators in ZFS environments.
The paper (presented at
the OpenStorage Summit
a few weeks ago) says that for high integrity operation in the event of power
loss and reboot - SSDs must guarantee correct and consistent implementation of
cache flushes (SCSI SYNCHRONIZE_CACHE command). It lists some popular flash SSDs
which don't.
A number of benchmark test graphs in the paper illustrate
how write IOPS
performance in some popular
2.5" flash SSDs is
non deterministic and degrades after as little as 10 minutes use - whereas in
RAM SSDs the
performance is constant.
Editor's comments:- although there's
nothing conceptually new in this white paper - (the
RAM vs flash SSD
debate was covered in a classic article in
2007 - while
the issue of halo effects in flash SSDs was
revealed in an article
in 2008) -
nevertheless it shows why some types of flash SSDs are unsuitable for some types
of enterprise apps (even before you get to the
question of MLC).
Idealstor says - USB3 better than eSATA for SMB disk backup
Editor:-
November 8, 2010 -
Idealstor
announced today the release of a
new rugged
USB 3
removable HDD based
backup product called the Bantam.
At time of launch capacity options are 320GB ($199), 500GB, 750GB and 1TB.
Bantam cartridges are made from a rugged aluminum design and come with shock
proofing which the company says will survive more than a 3 foot drop to a
tile over concrete floor. They ship with with Idealstor's Windows compatible
iBac Lite software - which
includes dedupe
options.
"For years we've offered businesses an enterprise class
removable disk backup
solution designed to completely replace tape based backup," said Nandan
Arora, CTO for Idealstor. "As much as our solutions were an affordable
alternative to tape, there
was a large segment of the market that needed a solution like ours but didn't
have the amount of data or the budget to afford even our entry level products.
We finally have a solution designed specifically for the SMB with the Bantam."
Editor's comments:- I asked marketing manager Ben Ginster
about performance - and where the name of the product came from.
Re
performance:- he said - "Speed depends on lots of factors and anyone
that gives you a "real world" speed is blowing smoke. I've seen speeds
up to 2.5GB/minute on some backups and less than 1GB on others. When we
originally were testing the unit we were planning on having eSATA and USB3 on
this drive but we found that USB3 speeds were faster than eSATA so we
decided to just go with USB3. We have controllers for (customers with) systems
that don't have USB3."
Re the Bantam (which for me having kept chickens - I had latched
onto as a opportunity to add yet another inmate to my
storage animal
metaphors zoo / article) - I was wrong. Ben Ginster told me " We came
up with name after the
Bantam
Weight in boxing/wrestling. Small but
powerful. If you pull up Wikipedia the Bantam weight in boxing was named after
a small chicken called the
Bantam so I guess
you could say we're named after an animal – indirectly of course." |
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