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1993-09-08
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HEWLETT-PACKARD COMPANY
Position Paper on Distribution Channel Disk Mechanisms
and HP Storage Solution Products
I. Introduction: Rationale for Position Paper
II. Statement of Compatibility Letter Sent To Distributors
III. Open Systems and SCSI Standards
HP DMD Distribution/OEM Drives vs. HP Storage Solutions Products
IV. Fully Tested and Integrated Solutions
What Tests Do We Do and Why
V. Problems with a Non-Tested Disk Mechanism
Warranty and Support Issues
Cost of Ownership Issues
VI. Benefits of a Tested Storage Solution
Performance Gains
Random Performance
Sequential Performance
Special Feature: "Sector Atomicity"
VII. Full HP Support & Single Vendor Relationship
Sales, Configuration & Installation Support
Industry Leading Service and Diagnostics Support - HP Warranty
VIII.Summary
IX. Additional Sales Resources
HP INTERNAL USE
HEWLETT-PACKARD COMPANY
POSITION PAPER ON DISTRIBTUION CHANNEL DISK MECHANISMS
I. Introduction: RATIONALE FOR POSITION PAPER
In May, 1993, Disk Memory Division (DMD) sent a letter to all of
its U.S. distributors. The letter contained a formal statement
of compatibility for HP OEM disk drives sold through the
distribution channel. This statement plus supplemental infor-
mation is now being sent to HP Sales Force 40 to provide the direct
and VAR/OEM sales force with a consistent message to share with
customers regarding the compatibility of various disk storage
solution products with host systems. This position paper was
developed to address potential questions on the compatibility of
HP's and other vendors' distribution/OEM disk mechanisms which
claim to support the SCSI protocol with HP Workstations, Business
Systems and Servers.
This White Paper contains additional information which has been
appended to the statement (duplicated below) in order to provide
greater insight into the issues affecting connection of various
disk mechanisms and storage solutions to a variety of HP host
platforms.
II. STATEMENT OF COMPATIBILITY (DUPLICATED STATEMENT)
STATEMENT OF COMPATIBILITY
--------------------------
FOR HP DISTRIBUTION CHANNEL DISK MECHANISMS
-------------------------------------------
All Hewlett-Packard SCSI OEM disk mechanisms sold through distribution
channels are designed to be compatibile with open architecture systems
that allow standard SCSI disk mechanisms to be connected to them.
(Note: Some systems are NOT open architecture and do require specific
drives and/or firmware in order to function properly.)
Regardless of platform (i.e. HP, Sun, DEC, IBM, Apple, etc.), it is the
responsibility of the purchaser of the HP OEM SCSI disk mechanism
purchased through an HP distributor to verify that it works as expected
in their intended application.
Customers using HP computer systems are encouraged to consult with
their HP computer system sales or service representative to verify
compatibility and performance expectations before installing onto their
system an HP OEM disk mechanism purchased through an HP distributor.
III. OPEN SYSTEMS AND SCSI STANDARDS
Theoretically, HP and other vendors' distribution/OEM disk mechanisms
should be compatible with any open architecture system which supports
standard SCSI drives. In reality, however, this is rarely true because
there are no set SCSI interface standards. (An HP disk drive does not
respond identically to a Seagate disk, which does not respond the same
way as does a Fujitsu disk, and so forth, although they all use the
SCSI protocols.)
Because hardware and software vendors have slightly different
interpretations of SCSI specifications and may implement SCSI commands
differently, extensive integration testing must be done to ensure the
compatibility of the host system and disk mechanism.
In addition, system vendors like HP usually add performance
enhancements and unique features in order to provide additional
competitive value for their customers. Testing must also be done to
ensure that these features and enhancements are supported, particularly
as various releases of the Operating System are distributed.
Therefore, many system vendors restrict their support and warranty to
those products or solutions which they have tested and can ensure
compatibility.
HP is committed to open architecture systems and SCSI standards, and
has strong representation on committees charged with defining these
standards. However, at this time there is not yet a widely adopted,
robust set of standards which ensure full compatibility for all SCSI
devices, nor is there a definitive standard which strictly defines what
constitutes a SCSI device beyond some minimum
communications/connectivity parameters. Thus, to ensure fully
functional compatibility of system and storage solution, extensive
testing must continue to be required until such time as established
standards are adhered to by both system and disk mechanism vendors.
This is the only way to guarantee that customers are getting a solution
with features which they expect.
HP DMD DISK MECHANISMS VS. HP STORAGE SOLUTIONS PRODUCTS
--------------------------------------------------------
HP DMD sells disk mechanisms which may be integrated into a variety of
computer system solutions, if the system vendor or a third party has
tested and completed the integration work required to ensure
compatibility. Similarly, DMD and other HP divisions utilize HP disk
mechanisms as raw components to be enhanced and then integrated into
more complete storage solutions.
A crucial difference between these mechanisms and the storage solutions
products is the extensive testing performed to ensure compatibility and
complete integration into HP Workstations, Business Systems and
Servers. These tested solutions are the only products HP will guarantee
support. Why? Because there ARE DIFFERENCES between the distribution
channel HP disk mechanisms and those used in HP storage solutions
products. These differences are described in detail on the following
pages.
IV. FULLY TESTED AND INTEGRATED SOLUTIONS
WHAT TESTS ARE DONE AND WHY
---------------------------
HP testing is designed to ensure that the host system and the storage
system work together and function properly as an "integrated solution"
under a wide range of operating conditions.
The integrated solution includes: the host system, operating system,
disk mechanisms, other storage mechanisms, enclosure, power supply, and
interface connections. Testing for potential problems in the normal
range of operations as well as extreme conditions such as maximum
loading configurations, marginal overloads, and partial - to full-power
failures are performed. The primary purpose of the exhaustive testing
performed by HP is to clearly define compatibility needs and then
design a family of products to provide a range of recommended solutions
for customers. Only HP tested solutions should be recommended as
viable solutions to customers. A similar recommendation cannot be
generalized in reference to a third party or OEM/Distributor storage
solution, regardless of whose disk mechanisms is utilized as the raw
component.
Extensive HP compatibility testing has shown that compatibility
problems do occur with regular frequency with HP pre-release products
as well as others. These problems can only be resolved through
exhaustive testing and must be addressed prior to release of the
product. The difference between an HP certified solution and the
"other solution" is that HP designs the storage solutions products to
ensure the integrity of the whole system under a variety of potential
operating conditions. The following are typical test scenarios:
Type of Test Purpose of Test Types of Problems
______________ _________________________ _____________________________
Configuration Test extreme, maximum Electronic "noise" or random
Tests configurations errors can be detected
including: Disks, DAT, (random errors are difficult
CD-ROM: What would happen to replicate and isolate as
if the SCSI cable length the SCSI bus can be reset to
is exceeded? Are older clear the error symptom, but
products fully compatible the error cause persists.)
with new products? Probable intermittent (and
potentially undetected) data
corruption could occur as a
result.
______________ _________________________ ______________________________
Regression Do the host system and If the systems do not "Speak
Tests storage system speak to to each other properly, then
each other properly? the disk drive may "hang" or
Are the commands fail to respond to further
correctly interpreted by system commands. Depending
both systems in proper upon what activity the drive
time sequence? was performing, this may
cause I/O errors and data
loss; if the system was
swapping memory to a swap
area, it would cause the
system to halt.
______________ _________________________ ______________________________
Power Fail What happens when the Over 2 weeks of testing are
Tests power fails (partial and done to test the effect of a
full power failure)? Do variety of power fail
the systems shutdown conditions upon data integrity
gracefully and properly? E.g., should a disk drive lose
power during a sector write,
data in that sector would be
lost or corrupt. (See Sector
Automicity as an HP solution
to this problem.)
______________ _________________________ ______________________________
Fault Tests What happens when faults If a fault or error occurs,
or errors occur? Does the O/S and host system
the disk drive handle the expect the disk drive to
fault in a robust exhibit a specific response
fashion, and maintain to the fault/error. If the
data integrity? response is outside a narrow
range of parameters, the
system may lose data, and in
worst case, halt. In either
case the system will inhibit
normal operations.
______________ _________________________ _____________________________
Boot/Load Do the disks work as a If the disk is to be
Functionality boot device? Do they supported as a boot device,
Tests return the proper status it must consistently respond
report and power on? to system firmware commands
within a specific time
interval. The disk and the
system must communicate using
exactly the same command set
within exactly the same time
interval.
______________ _________________________ ______________________________
Beta Tests Do the products work in HP tests products in extreme
customer environments? environments which are
supersets of potential
customer environments to
ensure identification of all
classes of problems, and to
develop "fixes" for these
problems classes.
______________ _________________________ ______________________________
Performance Do the products deliver HP tests disks with the host
Tests the expected performance system to accurately measure
and throughput as they data throughput, and ensure
were designed to do? that throughput matches or
exceeds design specifications.
Performance tuning strategies
are also implemented to
increase performance for
customer environments.
______________ _________________________ ______________________________
Diagnostic Do the diagnostics work Diagnostics are integrated into
Tests properly so that HP CE HP solutions in order to assist
and SE personnel can CE's and SE's in identifying
detect and resolve error true causes of disk problems.
conditions? Without comprehensive
diagnostics available the
primary recourse is to swap out
the disk mechanism without
really addressing the potential
problem source such as O/S or
host system.
_____________ __________________________ _____________________________
ESD, EMI, RFI Are drives and CPU All HP storage solutions
Tests immune to electrostatic products are test with the
discharges? Do products host system and supported HP
conform to FCC emission peripherals to ensure that the
standards to eliminate complete solution meets or
potential Radio Frequency exceeds all applicable
Interference with other standards for the destination
System components? country.
______________________________________________________________________
As these tests demonstrate, it is a misconception that one can "plug
and play" any SCSI device to any system which supports the SCSI
protocol. The SCSI protocol does increase the likelihood that the
devices will function together, though there is no guarantee that they
will function properly or optimally together. HP storage solutions
products are DIFFERENT from HP and other OEM channel disk mechanisms
becuase they have been designed and built to work in unison with HP
Workstations, Business Systems and Servers.
V. PROBLEMS WITH A NON-TESTED DISK DRIVE
What can happen if a customer connects a distributor/third party disk
mechanism which has not been tested to ensure compatibility with HP
systems to an HP system?
Response:
In HP Business Systems and Servers operating environments, data
integrity and system efficiency are of critical importance. The
operating system will query for specific information about the
disk drive and attempt to verify it. The disk's response to this
query will affect both how the O/S interacts with the mechanism
and its device driver as well as how the mechanism is configured
into the system. Problems such as inefficient disk partitioning
and improper setup may occur if insufficient or incorrect
parameters are provided. As a consequence the customer is at risk
for data corruption and/or loss, and also may create conflicts
with other system components.
The problem with a non-tested disk drive can include:
* Inability to partition the disk drive
* Inefficient use of capacity and space
* Inaccessible sectors on the disk drive
* Slower read/write performance than specifications
* Trouble in building a robust file system
* Non-working System Administration Management (HP-UX SAM) tools
* Non-supported Power Fail features
* Random I/O errors
* Incorrect configurations which may cause write transaction
errors and data loss
* Invisible data loss that is not evident until an attempt is
made to retrieve the data
HP Workstations make similar queries for disk drive parameters,
although not as exhaustive. In any case, some or all of the above
problems may still occur.
WARRANTY AND SUPPORT ISSUES
---------------------------
An HP storage solution disk product comes with a limited, one-year
on-site warranty. After the expiration of the warranty, the customer
can elect to purchase a variety of service contracts for their
products. What is constant is that full HP support for HP storage
solutions products will continue during the time the product is listed
on the HP Corporate Price List, and for five years beyond the date
when the product is listed for discontinuance.
HP Distribution/OEM disk mechanisms come with a five-year return-to-HP
parts only warranty. Essentially, if a disk drive in the distribution
channel fails, the customer will be responsible for removal of the
drive from the system, and for returning it to the distributor/OEM who
will then return it to HP. HP will repair the drive provided that the
problem actually results from a disk hardware failure and not some
other O/S or host system cause. HP will return it to the
distributor/OEM who then returns it to their customer. In this
scenario a several-day delay occurs in servicing the problem due to the
various handling steps. Further, in the distribution channel any
support and configuration services will also need to come from the
distributor. If the disk drive is incompatible to the host system, it
may be likely that significant resources are needed to resolve the
problem, IF it can be resolved. Distributors may not possess the
resources to perform comprehensive compatibility testing prior to sale,
and consequently may not have the ability to address compatibility
problems after the sale.
Some distributors may offer an option to purchase HP's support
services. Like many service organizations, HP makes available a
"multi-vendor" service contract which includes servicing products from
any vendor. However, this will not change the basic issue -- if the
drive is purchased from the distribution channel, it may not function
properly with the system. The service engineer will not, however, be
able to make them compatible.
COST OF OWNERSHIP
-----------------
Distribution disk mechanisms cost less than HP storage solutions
products. However, the complete cost of a product must be measured by
accounting for the invisible (to the customer) product integration
features as well as the cost of the raw disk mechanism. The cost of HP
storage solutions products includes both the integration product which
guarantees customers that the solutions will work effectively with
their system and the disk storage mechanism. The customer can save
time, energy and money while increasing both reliability and data
availability through purchase of HP storage solutions products.
Customers who are considering purchasing a distribution disk drive
should consider the following questions concerning use of uncertified
disk mechanisms:
* Have they researched whether the disk mechanism will work with
the system?
* What is their confidence level that the mechanism will work
under the wide range of operating requirements at their unique
site?
* Have they researched what tests (if any) were completed by the
third party/distributor, and whether those tests were
successful as well as sufficient?
* Do they understand the issues involved in properly configuring
and installing the distributor disk mechanism to the system?
* Do they recognize that the alternative solution may never
deliver 100% of their expected performance level, regardless
of the amount of effort they invest?
* What strategy do they have to recover from data corruption or
loss or system problems caused by compatibility problems with
a distributor disk mechanism?
Other cost of ownership questions to ask customers include:
* What is the value of system uptime?
* How important is data integrity?
* How critical is performance and efficient utilization?
* What is the value of a System Administrator's time? Is their
time better spent managing the system or trouble shooting
incompatible storage components?
* What are the long term support implications? Include
maintenance, upgrade capability, upgrade compatibility (e.g.,
with the SPU), reliability, compatibility with new releases
of the Operating System, compatibility with other system
components in this discussion.
Most customers will save money by purchasing HP Storage Solutions
products which will eliminate difficulties caused by incompatible
storage solutions.
VI. Benefits of a Tested Storage Solution
PERFORMANCE GAINS
-----------------
HP storage solutions products are optimized for high performance with
all HP Workstations, Business Systems and Servers. SIGNIFICANT disk
I/O performance increases can be seen. Performance improvements over
standard HP distribution mechanisms can be as high as 40%, although not
guaranteed.
Test data taken to show differences between HP's storage solutions disk
drives and HP distribution disk drives is shown below. In both cases,
these disk drives were taken straight off their respective production
lines.
RANDOM PERFORMANCE
------------------
Random performance is shown for the C3027U (1-GB disk drive for HP
storage solutions) and C2247 (1-GB disk drive for Distributors).
Random data accesses for the C3028U and C3010 (2-GB disk products) show
similar results (graph not shown). Random data accesses are
representative of data base and multi-user type applications. Moderate
performance improvements can be seen, especially for write intensive
environments (when the customer is updating files more than reading
them).
(See Chart 1 at end of document)
SEQUENTIAL PERFORMANCE
----------------------
Sequential performance is shown for the C3027U (1-GB disk drive for HP
storage solutions) and C2247 (1-GB disk drive for Distributors).
Again, similar results occurred for the 2-GB products. Sequential data
accesses are most representative of applications which operate on large
amounts of data at a time like video, graphics, and CAD. Significant
performance improvements can be seen, especially in write-intensive
environments (when customer is updating files more than reading them).
In less write-intensive environments some improvements can be seen.
Note that 18% improvement is about the same improvement that is seen
from one disk generation to the other and is the approximate equivalent
of one year's technology advantage.
(See Chart 2 at end of document)
SPECIAL FEATURES LIKE "SECTOR ATOMICITY"
----------------------------------------
HP storage solutions products for the HP Business Systems and Servers
have a unique feature called "Sector Atomicity" or Power Fail support
which distinguishes the disk drives from those sold through
distribution/OEM channel.
Power Fail support refers to the ability of an entire computer system
to shut down gracefully in the event of a power failure, and return to
normal operations once power returns. The disk drives offered in HP
storage solutions products have a unique feature which ensures data
integrity in the event of power failures. Data loss occurs when power
is interrupted while the drive is writing to a sector. HP storage
solutions disk drives can sense an imminent power failure or
interruption, and will protect against data loss by not beginning a
write if there is insufficient time to complete the sector. A patent
on this feature, "Sector Atomicity," has been applied for.
VII. FULL HP SUPPORT & SINGLE VENDOR RELATIONSHIP
HP storage solutions products are sold through HP's direct sales force
(SF40) and are supported by HP Customer and Software Engineers. This
channel is intended to provide customers with an integrated, FULLY
SUPPORTED solution from a single vendor. HP emphasizes a strong
commitment to customer satisfaction. Field sales and support personnel
are integral components in achieving this goal.
SALES, CONFIGURATION & INSTALLATION SUPPORT
-------------------------------------------
HP's customer experience indicates that most customers prefer a single
point of contact for their computer system needs, rather than dealing
with multiple vendors. This is particularly true in instances where
there are issues of function, compatibility, and performance. Storage
solutions products are an integral part of each system solution. While
the choice of a storage solution may be a component in achieving full
customer satisfaction, it is a choice which can have long lasting
effects upon the customer's relationship with HP. It is also a choice
which merits close attention by customers as they evaluate various
purchase alternatives. HP strongly encourages its customers to select
an integrated HP storage solution to maximize the performance and
functionality of their system, as well as the effectiveness of their
System Administration team.
HP's direct sales force can provide customers with:
* Product information from the entire range of HP products to
meet their needs.
* Optimal configurations of the entire system, including the
storage system, designed to meet the functional needs of
their unique information management environment.
* Knowledgeable recommendations on hardware, software and
peripheral solutions.
* Discounts based on their purchasing power.
The focus of HP's direct sales force is to act as a resource for
computer information, and assist the customer in defining and analyzing
their needs. In contrast distributors generally rely upon the customer
to do their own analysis and compatibility research. Customers should
thoroughly evaluate all vendor's statements concerning disk mechanism
compatibility, and should also develop a good understanding of how
thoroughly a vendor has tested any proposed solution. By purchasing an
HP storage solution direct form HP, the customer can leverage the
consulting and installation expertise of the HP field organization and
the thorough testing done at the factory.
INDUSTRY LEADING SERVICE AND DIAGNOSTICS SUPPORT - HP WARRANTY
--------------------------------------------------------------
All HP mass storage products come with a limited, one-year on-site
warranty provided by HP's superior service organization. the on-site
warranty includes:
* Services by a trained HP Customer Engineer (CE) who will
diagnose and solve a computer problem, should one occur.
* Complete product coverage including parts, labor and travel
to the customer site.
* Worldwide support services.
* Predictive diagnostics for preventive care of products. Using
predictive diagnostic software HP Customer Engineers can
detect potential problems before they occur and result in
downtime.
* Problem response support that extends from the customer site
to HP Division Lab and Product Engineers. Critical problems
can be escalated to draw upon the resources of the entire HP
organization.
* HP's commitment to resolving the customer's issue and
providing satisfaction.
* CE installation of the product is included with many HP
storage solution products, thus guaranteeing correct, timely
installation and configuration.
It is unlikely that most vendors, including distributors, will have
adequate resources to provide the breadth of coverage (worldwide), the
scope of coverage (recourse to Division resources), or the technical
skills (HP Customer, Lab, and Product Engineer's in depth training).
VIII. SUMMARY
When a customer purchases a HP storage solutions product, the customer
is getting a commitment from HP for a solution which has been fully
tested, qualified and supported. This commitment is backed by HP's
reputation as a provider of high quality computer products and industry
leading support services. HP personnel are committed to delivery of
fully integrated storage solutions which will maximize a customer's
investment in hardware and software, and to supporting those products in
the customer's environment.
A key element of all HP storage solution products is the thoroughness
and reliability of the testing process used to design and integrate
that product into the HP product line. Unless an alternative channel
or vendor possesses the resources and initiative to perform rigorous
testing at this level, customers should thoroughly consider all the
issues which constitute true host/storage solution compatibility.
The distribution channel fulfills an important part of HP's product
strategy. However, it is not intended to be an alternative channel for
delivery of uncertified storage solution products. There are critical
compatibility issues which must be considered when using mechanisms
distributed through this channel. Critical among them is the issue of
true compatibility, compatibility with future hardware and software
components/releases, and the ability to upgrade the storage solution to
future product releases. For that reason HP encourages customers using
HP computer systems to consult with their HP computer system sales or
service representative to address compatibility and performance
expectations before installing onto their system an HP OEM disk
mechanism purchased through an HP distributor. It is also the integral
value of an HP storage solution - it can deliver the promise of
compatibility to HP customers.
IX. Additional Sales Resources
SALES GUIDES HP MASS STORAGE SYSTEMS:
HP Series 6000 SCSI-2 Mass Storage Systems for HP3000/9000 Users
(P/N 5091-7256E)
SALES GUIDES: HP DISK ARRAYS
HP-FL Disk Arrays for HP 3000 Business Systems and Servers
(P/N 5091-6463E)
HP Fast/Wide SCSI Disk Arrays For HP 9000 Series 700
Workstations (P/N 5091-6460E)
HP INTERNAL USE
R2SCSI /RDbh