| articles
about iSCSI and IP / SAN on STORAGEsearch.com |
article:- the State of iSCSI,
SAS, SATA and InfiniBand (Q3 2006)
5 years after
STORAGEsearch.com launched dedicated pages to 4 new storage interfaces - we
went back to see how successful they'd been in the market compared to their
original promise.
article:- the
State of iSCSI? (2004)- we interview PyX Technologies
"There
is little awareness that iSCSI has different levels for fault tolerance within
the protocol or that not all iSCSI-enabled products are fully compliant with the
protocol as written." ...PyX
Technologies profile
article:-
iSCSI take-up in Europe 2004-2005 - by FalconStor
"With
the benefit of hindsight, it looks now as though I may have been over-optimistic
as to the levels of take-up of iSCSI in 2004 - but, ironically, because I was
right: iSCSI has, after all, had to go through a normal evolutionary cycle, and
that cycle has simply taken longer than the twelve months I predicted."
...FalconStor profile
article (on
archived news) - Running with iSCSI - by FalconStor
"Large
organisations see iSCSI deployment as an opportunity to extend the benefits of
their datacentre FC SANs to distributed application servers, while mid-sized
organisations, often regarding FC as a substantial investment, see an
opportunity to get on the SAN bandwagon with a smaller investment."
...FalconStor profile
article:- iSCSI is
now a market reality
"iSCSI was the vaporware
product of the year 2002. The summer of 2003 has witnessed a couple of
important milestones which have changed all that."
storage history
article:-
Cancer Therapy and Research Center Uses iSCSI Technology - by Datalink (pdf)
"CTRC chose the iSCSI solution to mirror the data
because it was more cost effective than "server-to-server" or "storage-to-storage"
replication architectures. Plus, it was the only way they could meet their
standard to not be down for more than 10 minutes."
...Datalink profile |
| articles
about iSCSI on other sites |
article:-
Securing Storage Area Networks with iSCSI - by EqualLogic (pdf)
"While firewalls and IPsec protect packets at the IP
level, iSCSI provides a request and response login procedure to ensure that only
trusted iSCSI initiators can access the storage behind a particular target. When
an iSCSI initiator connects to a target, the login procedure authenticates both
the initiator and the target and sets iSCSI and security protocols for the
session. SCSI commands can be sent only after the login completes."
...EqualLogic profile
article:- FAQS about IP
Storage and iSCSI RAID - by StraightLine
"Why
use iSCSI or an IP SAN when we have a NAS? - This is a great question. Two
big reasons: performance and data access. If you place an iSCSI RAID on the same
network as a NAS, the iSCSI RAID will out perform the NAS by about 3.5 times.
Please see our performance section. Data access is a broad topic. Backup is much
simpler for an iSCSI RAID. Mutliple paths to an iSCSI RAID, ie. through
different switches, is a network setup furnction. Using iSCSI in a cluster as a
safeguard against host failures is possible."
...StraightLine
profile
article:-
The Total Economic Impact. of Network Appliance IP-SAN Solutions (pdf)
"Upon implementation of NetApp IP-SAN solutions, each
interviewed organization reduced the number of Exchange servers and experienced
savings associated with Exchange server hardware, licensing, and management
complexity. For our sample organization, we estimate that the licensing,
infrastructure, maintenance, and support cost savings associated with a
reduction of two existing servers would be $3,500 per server, per year . or
$7,000 annually for a total three-year savings of $21,000. Each organization
cited the comparative simplicity of managing an iSCSI SAN versus a DAS (or
Fibre Channel SAN). Customers indicated that NetApp.s IP-SAN solutions represent
simple, scalable, and affordable technology for their networked storage
requirements." ...Network
Appliance profile
article:-
IP SANs to Replace NAS - by SANRAD (pdf)
"This
document reviews the advantages and disadvantage of NAS vs. SAN, how NAS vendors
address their disadvantages, and introduces an IP SAN solution, which combines
any disk storage system with SANRAD's iSCSI V-Switches. This complete IP SAN
solution will deliver a better solution than NAS."
...SANRAD profile
article:-
iSCSI FAQs - by Network Appliance
"The iSCSI
protocol is expected to accelerate the transition from direct-attached storage
to networked storage by reducing the costs and complexity traditionally
associated with SAN deployment and making it feasible to deploy SAN storage
solutions in places where Fibre Channel SANs are not cost-effective."
white paper:- iSCSI
FAQs - by Cisco, HP and IBM
This is a much more
technical FAQs than the otherswe've linked to. Here's an sample extract:- "Connection
reinstatement is the process of an initiator logging in with an ISID-TSIH-CID
combination that is possibly active from the target's perspective, which
causes the implicit logging out of the connection corresponding to the CID,
and reinstating a new Full Feature Phase iSCSI connection in its place (with
the same CID). Thus, the TSIH in the Login PDU MUST be non-zero and the CID
does not change during a connection reinstatement. The Login Request
performs the logout function of the old connection if an explicit logout was
not performed earlier. In sessions with a single connection, this may
imply the opening of a second connection with the sole purpose of cleaning up
the first. "
article:- iSCSI:
Networked Storage for the Masses - by HDS (pdf)
"Until
the recent emergence of iSCSI - the application of SCSI storage device protocols
to conventional IP networks - storage networking remained beyond the grasp of
many small and medium-sized companies that could benefit greatly from its
advantages." ...Hitachi
Data Systems profile
article:-
iSCSI FAQs - by Technomages
"Question 9 - Do
I need to build a separate network for iSCSI SAN? Answer: No, in most cases you
do not. One of the major advantages of iSCSI over Fibre Channel SANs is that it
utilizes existing IP infrastructure. In some cases, however, it might be
desirable to separate storage traffic into a dedicated network for performance
reasons. This is especially true for installations which do not have a Gigabit
Ethernet network installed."
...TechnoMages profile
article:- How
iSCSI Works - by ArdisTech
"There are a few
things you should be aware of when designing an IP SAN, however. First, TCP has
some inherent overhead embedded in the protocol. This is necessary when
transmitting over unsecured and potentially unstable networks (e.g., the
Internet). This overhead reduces performance of the theoretical speeds of
Ethernet. Additionally, the faster the implementation of Ethernet, such as
1Gbps, the larger and more frequent the TCP overhead will be on the servers and
clients in the network. One major reason folks have had to upgrade their servers
when migrating to 1Gbps Ethernet can be traced to the simple fact that they're
now handling roughly 10 times the TCP they were before. This can severely
cripple, even crash servers that are only a couple years old."
...ArdisTech profile
article:-
4 Common Problems iSCSI Solves - by Adaptec
"iSCSI
SANs help IT managers meet their budgetary constraints by allowing them to add
storage when needed without having to significantly increase headcount to manage
the storage. In addition, the flexibility to add storage on the fly eliminates
the guesswork in deploying storage for anticipated growth and allows IT managers
to fully utilize the purchased storage."
...Adaptec profile
article:-
A Quick Guide to iSCSI on Linux - by Cuddletech (pdf)
"It's
important to understand that iSCSI, unlike NAS, makes block devices available
via the network. Effectively, you can mount block devices (disks) across an IP
network to your local system and then use them like any other block device.
Generally when you first use an iSCSI device you're going to need to partition
it, label it, and create a filesystem on it. Unlike NAS your kernel will be able
to read and write to your new iSCSI device just as if it were a local hard disk
and therefore you can use any filesystem you like (EXT2/3, JFS, XFS, ReiserFS,
etc). Also, because it is being handled as a block 2 device only one (1) system
can use the iSCSI device at a time! (This changes if you use a global
filesystem, or read-only filesystem.) So just like Fibre Channel you're not
making 4 machines access 1 filesystem, but instead you're allocating 4 chunks of
disk on one large device and making it avalible via an iSCSI target so that 4
initiators can access it."
article:-
iSCSI Technology - by Crossroads Systems
"The
concept of pushing SCSI, or block oriented storage commands, over a serial
interface is not really new technology. Fibre-Channel, IEEE-1394 (Firewire) and
USB have been doing this for a number of years already. The major difference
between these buses and the buses that carry TCP/IP is that IP based buses were
never intended to be used as storage transports, which require sequenced ("in
order") delivery, guaranteed timing, and robust error correcting."
...Crossroads Systems
profile
article:-
A beginners guide to iSCSI - by McDATA
"As
someone who has worked in Fibre Channel for some years, I am afraid I have to
point out to the Fibre Channel world that iSCSI can run at wire speed and
certainly can run as fast as any normal server running normal applications. To
the IP community, I would like to point out there is a lot of Fibre Channel out
there -- particular comparing the numbers with the number of 1GB network ports
rather than any network ports. To the Fibre Channel community, I must point out
that while a lot of storage and even a lot of high-end servers are connected to
Fibre Channel, there are still quite a few Unix servers not connected and the
vast majority of the Intel server community is not Fibre Channel connected."
...McDATA profile
article:-
Newcomer iSCSI promises to enable the SAN market in ways incumbent Fibre Channel
can't - EDN magazine
"Many storage
applications call for low latency. How then, does another layer of protocol
reduce Ethernet latency? The truth is: It doesn't. Thus, the introduction of the
TOE (TCP/IP offload engine), which moves all or part of TCP/IP processing from a
host processor to hardware-based processing. TOEs form a key part of the iSCSI
story by reducing overall latency and host-CPU usage and allowing the CPU to
manage connections from a session rather than a packet perspective."
article:-
"I want my iSCSI!" Easier said than done - Computer Technology Review
"The iSCSI protocol is designed to have no single
point of failure, to aggregate all available bandwidth and to be tolerant of
hardware and service provider failure. Many of these features only operate
properly in the upper Error Recovery Levels of the protocol--the same ERLs which
most vendors have chosen not to include in their iSCSI stack. Further, if one
looks at most of the iSCSI products--many of the iSCSI HBAs and TOEs available
on the market today--most have only a single Gig-E port. Even if one installs
two of these devices (heat considerations aside, natch), this leaves the problem
of aggregation across subnets unaddressed: You still can't get there from here.
To properly configure the upper Error Recovery Levels (ERL 2 in particular) one
simply must have more than one port on an HBA. This is assuming, of course, one
acknowledges that a single port, by definition, creates a single point of
failure. " Storage
publications |
| article:-
Why Upgrade Your Servers? - SSDs P.....e Superior ROI for a Bank - Case Study
(pdf) | |
| iSCSI Grew
4x Faster than NAS Market in Q407 |
FRAMINGHAM, Mass
- March 6, 2008 - Worldwide external disk storage systems factory revenues grew
9.8% year-over-year in Q407 totaling $5.3 billion, according to IDC.
Capacity shipped grew 56.3%. Network
disk storage grew 16% but the hot spot was
iSCSI with 70% revenue
growth.
For the full year,
EMC maintained its lead in
the external disk storage systems market with 22% revenue share, followed by
IBM and
HP.
Dell,
Hitachi, and
Network Appliance
ended the year in a statistical tie to round out the top 5. In this group
Network Appliance and Dell posted the strongest year-over-year revenue growth
during 2007, with 19% and 17% growth, respectively.
...IDC profile,
Market research
Editor's
comments:- for most of us (whose bonuses aren't linked to these numbers)
there's been no significant change in overall revenue growth in this part of the
storage market for many quarters. So you might say - what's new?
One
thing I'd say - is note the growing gap between the
hard disk market
which is growing nearly twice as fast as the "external disk systems
market". That's due to a black hole in consumer products which is sucking
in disks as fast as anyone can make them. And maybe due to lower margins in the
enterprise storage market due to competition from what IDC lumps together as "others"
- who have been trimming some of the fat off the top 5's oligopoly.
Another
thing, which IDC comments on is that the doom and gloom from the worldwide
financial markets doesn't seem to have slowed down this market. | |
| . |
Nibble:-
Re: iSCSI and FCIP
iSCSI (Internet SCSI) is a software
package which emulates SCSI protocols, but the connection method is via an IP
network instead of a direct SCSI compatible cable.
SCSI is an
intelligent protocol which enables data blocks to be read from or sent at high
speed to a storage device such as a disk or tape drive. Early implementations of
SCSI used ribbon cable and industry standard logic levels.
The promise
of iSCSI is that storage management software which was orginally written for the
well established SCSI standard, can now be used to make a remote disk or tape
drive on a network operate just like a local disk. The network can be a local
area network such as ethernet, or even the Internet. The potential benefit is
that users can connect to remote storage devices to replicate data without
having to invest in writing huge amounts of new (buggy) software.
Similarly
FCIP or Fibre Channel over IP emulates SAN
functionality over an internet connection. | |
| . |
| There
are
hundreds
of articles about SSDs on StorageSearch.com |
Here, below, are some
examples.
- RAM Cache
Ratios in flash SSDs - it's important to know the underlying RAM cache
architecture - even if you're happy with the R/W and IOPS performance.
- 2010 - 1st Fizz
in the SSD Bubble? - even the dogs in the street know this is going to be a
multibillion dollar market. Greed will play as big a part as technology in
shaping the
SSD year ahead.
- the pros and cons of
using SSD ASAPs - auto tuning SSD appliances are a new category of SSD
which entered the market in the 2nd half of 2009 to accelerate servers without
needing human tune-ups. How can you tell if they are right for you? And how
well do they work?
- the Problem
with Write IOPS - in flash SSDs - long established as a useful performance
modeling metric - this article explains why some specs are exaggerated when
applied to flash SSDs - or predict the wrong results for many common
applications.
| | | |
