IBM Storage

Storage Needs for Blockchain Technology- Point of View

Document version 4

© Copyright International Business Machines Corporation 2018.
US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule
Contract with IBM Corp.

Storage needs for blockchain technology point of view

Contents
Contents ........................................................................................................................... 3
List of figures .................................................................................................................... 5
Introduction ....................................................................................................................... 6
1

2

Blockchain ledger storage calculations ................................................................. 9
1.1

Blockchain ledger assumptions ................................................................. 9

1.2

Calculation ................................................................................................ 9

Off-chain storage requirements .......................................................................... 10
2.1

Off-chain assumptions............................................................................. 11

2.2

Calculation .............................................................................................. 11
2.2.1

3

Storage required for documents ............................................................. 11

Performance ....................................................................................................... 13
3.1

Service-level agreements ........................................................................ 14

4

Storage specification ........................................................................................... 15

5

Processing requirements for off-chain data stores ............................................. 15

6

Blockchain data management ............................................................................. 15

7

6.1

On-chain data management .................................................................... 16

6.2

Off-chain data management .................................................................... 16

Does the source blockchain matter? ................................................................... 183

8

Summary and recommendations ........................................................................ 19

References ..................................................................................................................... 20

4

Storage needs for blockchain technology point of view

List of figures
Figure 1: What is a blockchain? ........................................................................................................ 6
Figure 2: Hyperledger structure ........................................................................................................ 7
Figure 3: IBM Blockchain Architecture Example ............................................................................... 8
Figure 4: World-wide blockchain projected spending ........................................................................ 8
Figure 5: Graph of storage required per TPS per year for blockchain ledger (IBM calculation)...... 10
Figure 6: Required storage for off-chain data based on transactions per second .......................... 12
Figure 7: Blockchain peer storage .................................................................................................. 13
Figure 8: Off-chain data store configurations .................................................................................. 13
Figure 9: Example NVMe-based storage system ............................................................................ 14
Figure 10: Cryptokitties was the first success for Ethereum ERC721 blockchain ........................... 18

5

INTRODUCTION
Pioneered by cryptocurrencies such as bitcoin and Ethereum, blockchain is a model for a distributed,
trusted, shared, ledger in which you can store transactions. Each transaction is encrypted andidentified by a cryptographic signature that is chained to the previous block through additional
cryptographic keys. This allows for the blockchain to be a shared, immutable source of truth as eachblock stores a hash or signature of the previous block. Thus, any change to a block would require
recalculating all subsequent blocks and updating the entire chain. Figure 1 shows this concept.

Figure 1: What is a blockchain?

The cryptocurrencies use either proof of work (PoW) or proof of stake (PoS) to be a member of thechain. PoW is a set of complex calculations that result in the creation of a new bitcoin and someestimates suggest that the computations require an equivalent of 5 to 7 kilowatt (kW) of energy be
used per bitcoin. Obviously, PoW blockchains are not a high-performance option. PoS blockchainsallow you to purchase into a blockchain, slightly more performant but still not a good way to perform
thousands of transactions per second (TPS). A PoW blockchain can currently perform about 10 TPS
under test and around 3 in reality, whereas a PoS can perform about 20 TPS under test and 6 to 8
TPS in reality. Both of these are non-permissioned blockchains where no one knows the otherparticipants other than their hashed, encrypted identifiers.
Bitcoin is a PoW and Ethereum is a PoS. In PoW, you must utilize a cryptocurrency that you havemined to be a member, and in PoS, each blockchain transaction requires that you havecryptocurrency you have purchased. Each Ethereum transaction requires that you provide gas,
which is a subset of an Ether, the cryptocurrency of Ethereum. Currently, Ethereum is one of the
only cryptocurrency-based blockchains that provide (through their ERC721 specification for nonfrangible tokens) non-cryptocurrency assets to be traded. A frangible token is a single ether or single

6

Storage needs for blockchain technology point of viewbitcoin that can be subdivided. A non-frangible token would be a car, house, diamond, or other asset
that is normally sold as a complete unit.
The Hyperledger blockchain model is a permissioned, non-POW, non-POS model. Essentially, you
can become a member by being approved by the other members and can fully participate without
onerous calculations or having to purchase each transaction. Because no POW or POS is required
to use Hyperledger, it can support transaction rates that are impacted by the server computing
power and speed of the underlying storage, aside from the wrapping code such as the blockchain
smart contract. The current performance is 3500 TPS for a Hyperledger-based, performanceoptimized blockchain. It is projected that this could soon reach as high as 30,000 TPS. Hyperledger
based blockchains can be utilized to deal with both frangible (fungible) and non-frangible items.
Figure 2 shows the Hyperledger structure.

Figure 2: Hyperledger structure

Blockchain requires both on-chain storage of the core ledger data and off-chain storage of datarequired by smart contracts for verification and documentation. This is demonstrated in the IBM®
Blockchain architecture example leveraging IBM Cloud Private as shown in Figure 3.

7

Figure 3: IBM Blockchain Architecture Example

Blockchain is becoming a disruptive technology in payments, logistics, medicine, and anywhere atrusted, provenanced, immutable ledger is required. According to IDC, blockchain spending is
projected to reach an upwards of USD $11 billion by the year 2022. This is shown in Figure 4.

Worldwide Blockchain Spending by Industry,
2017–2022 ($M)
14000
11,744.40

12000
10000

8,397.70

8000
6000

5,067.10

4000
2000

2,857.20
754.4

1,531.30

0
Total
2017

2018

2019

2020

Figure 4: World-wide blockchain projected spending

8

2021

2022

Storage needs for blockchain technology point of view

Recent studies have shown that permanent storage for blockchain data can cost as much as USD$100 per gigabyte (GB). Within the Hyperledger environment, it has been estimated that storage forthe blockchains alone, in medium to high-level transaction environments, could be as high as 197
terabytes (TB) or more per year. Figure 5 shows the estimated storage required per transaction persecond, per year.
Attempting to find hard data for the storage required for Hyperledger blockchain, for either on-chain
or off-chain data is difficult due to the newness of the technology and lack of hard documentation byusers who are using it in their daily operations.
As we previously stated, the blockchain ledger is currently immutable. This means that it is appendonly and cannot be pruned. Calculating the blockchain ledger storage requirement may not be as
trivial as everyone assumes. While pruning may come into play in the future for certain industries, it
is expected that some other industries, such as financial and medical, may need to adhere toproscribed retention requirements (some for 50 years). So, even if ledger data is pruned from theprimary chain, it will still have to be maintained in an archive storage somewhere either in the cloud
or on premises.

1

Blockchain ledger storage calculations

Given a basic understanding of storage and some basic understanding of how blockchain storesdata, you can derive a back-of-the-envelope calculation on how much storage is required for theblockchain ledger.

1.1

Blockchain ledger assumptions

The following assumptions are made in the blockchain ledger storage calculations:
•
•
•
•

•

1.2

All calculations will be in actual bytes, that is 1024 bytes is 1 KB.
All Hyperledger blocks are 1 megabyte (MB).
Only hash, signature, or key data is stored in the blockchain ledger.
The company works 8 hours per day. The company has roughly 240 processing days per
year and the number of transactions per second are averaged over those days only (allows
for holidays and weekends.)
Currently bitcoin is storing about 1400 basic transactions per MB block. So, Hyperledger
blockchains have larger headers and a bit more robust transaction size so 1000 transactions
per block was used as a mark in the sand.

Calculation

Using the assumptions in the previous section, the calculation to find out the amount of storage
required per TPS becomes (example for 1000 TPB):(1 TPS/1000 transactions per block)*1024 KB/block*3600 sec/hr*8 hr/day*240 days/year=
7,077,888 KB of data per transaction per year
= 6,912 MB

9= 6.75 GB= 0.00659 TiB/transaction/yr
Figure 6 shows the application of this value at various transaction levels.

Blockchain Storage per TPS per Year
1200
1000

TiB/yr

800
600
400
200
0

1

10

100

1000

10000

30000

TiB/Yr(1000)

0.00659

0.0659

0.659

6.59

65.9

197.7

TiB/Yr(500)

0.013

0.132

1.318

13.180131.800

395.400

TiB/Yr(205)

0.032

0.321

3.215

32.146321.463964.390TPS
TiB/Yr(1000)

TiB/Yr(500)TiB/Yr(205)

Figure 5: Graph of storage required per TPS per year for blockchain ledger (IBM calculation)

So even at a modest transaction rates, storage for Hyperledger blockchain ledger is in the terabyteor multi-terabyte size. Using the most conservative estimate of 1000 transactions per block for the
100 TPS level of blockchain activity, 0.659 TiB of storage per year is required. Going with theestimate of 5 KB per transaction, which is based on the actual test values from the Hyperledger
team, only 205 transactions per block has been achieved. At 205 transactions per block, the same
100 TPS would require 3.215 TiB of storage per year.
To put this all in perspective, based on the total size of the ledger and total number of transactions
stored, bitcoin is averaging close to 555 bytes per transaction or 1,889 transactions per block andEthereum is close to 2 KB per transaction or 512 transactions per block.

2

Off-chain storage requirements

Since it is not recommended to store non-transaction data, such as pictures, contracts, PDFs, andpersonal information in the actual blockchain ledger, some form of off-chain or sideDB storage isrequired. Off-chain data can be structured or unstructured. A hash or signature for the off-chain item
will be generated and that is what is stored in the blockchain ledger. The actual item is either stored
in the cloud, on premises, or in a near-cloud storage. It is expected that the required storage for offchain data will exceed the needs of blockchain ledger storage.

10

Storage needs for blockchain technology point of view

Some regulations, such as General Data Protection Regulation (GDPR) specifications for theEuropean Union will also affect how data is stored within a blockchain network. Quoting Bertrand
Portier - IBM Distinguished Engineer, Blockchain in Financial Services:“One of the GDPR requirements is the right to erasure which is when an individual asks anorganization that has their personal data to completely remove that data. The organization then has
a limited time to comply. Well, if you know blockchain, you know that the blockchain ledger isappend-only and immutable — there is no “undo” button after a write, and the chain of blocks
contains historical transaction information that goes all the way back to when the blockchain was
created. That can be a challenge for applying blockchain to GDPR. To comply with GDPR, no
personal data should be put on the blockchain directly. Techniques exist to deal with this, which
consist of putting a cryptographic hash on the chain or the “evidence” instead of the actual data.
More guidance and expertise needs to be collected in this space. And, as my Promontory colleagues
would say, “Be sure to check with your legal counsel!”

2.1

Off-chain assumptions

The following assumptions are made in the off-chain storage calculations:

•
•
•
•

2.2

Each transaction does not produce a document. For calculation, a ratio of three transactions
for each document is used so a figure of 0.3 is used.
8 hours per day is the workday.
240 days per year are actual processing days.
Indexing and other storage requirements are not included.

Calculation

Using the assumptions in the previous section, the calculation becomes:
1 TPS*docs per transaction*3600 sec/hr*8 hr/day*240 day/year = Documents per year
= 3*3600*8*240 = 814,301 Documents per year for 1 TPS
2.2.1 Storage required for documents
According to current references 1,000,000 documents, of mixed formats, requires 333 GB of
storage. This means, 814,301 documents will require:
1000000X/(333*814301) = GB/year/TPS
X = (333*814,301)/1,000,000= 271 GB/TPS/year= 0.264 TiB/Year/TPS
Figure 6 shows how this storage required per TPS will result in increased storage requirements as
TPS increases.

11TiB/yr

Blockchain Off-chain Storage per TPS per Year
9000.00
8000.00
7000.00
6000.00
5000.00
4000.00
3000.00
2000.00
1000.00
0.00

7939.452646.48
0.26

2.65

26.46

264.65

1

10

100

1000

10000

30000

TPS
TiB/YrFigure 6: Required storage for off-chain data based on transactions per second

So, as expected, you can see if the transactions produce 1 document for every three transactions
recorded, the off-chain storage requirement for blockchain will soon exceed those required for theblockchain ledger by an order of magnitude.
Some blockchain implementations leverage already-stored support information for their off-chain
data store. This leads to an unrealistic expectation that no additional off-chain data store will be
required for blockchain networks. Even when leveraging existing data, some peers are choosing tomove the data they want to share to a separate storage before they present it to their blockchain
network. However, many blockchain implementations are requiring additional new off-chain data, be
it on premises, or, in the cloud (or a combination of both). As the technology matures, more of thisoff-chain data will be generated and, for the peer to satisfy the blockchain SLA, its off-chain data willneed to be stored in dedicated data stores designed to provide optimal access to this data for all
network peers. Moreover, some network peers are choosing to duplicate off-chain data, even if for ashort duration, during which they experience a high usage of this data.
One final point is that each peer that participates fully in the blockchain will own a node and will
require off-chain storage. The amount of storage specified in these sections on on-chain and offchain storage are per node. Figure 7 demonstrates this concept.

12

Storage needs for blockchain technology point of view

Figure 7: Blockchain peer storage

3

Performance

There are various types of storage configurations that can be implemented for the blockchain offchain data store. Network speed, peer location, cloud vs on premises blockchain network
implementation, will play a role in the overall performance of a blockchain network. Aside from theperformance delivered by the compute and the software that makes up and supports the blockchain
environment, off-chain data store performance becomes another focus item. Having to cobble
together access links to existing data stores or setting up the wrong off-chain data store might cause
unacceptable performance to the whole blockchain network. Figure 8 below depicts 3 various
example of off-chain data store configurations.
Example 1

Example 2

Example 3

Figure 8: Off-chain data store configurations

Aside from on premises or in the cloud, the off-chain data can also be stored in near-cloud storage indedicated data stores. This is known as cloud-edge storage. In file systems, such as Internet
Protocol (IP) file system or the InterPlanetary File System (IPFS) which forms the basis for the13InterPlanetary Data Base (IPDB), each member is responsible for storing and sharing their off-chain
data with all other members in the blockchain network. In such a file share system, the weakest link
will be the member with the slowest off-chain storage, assuming that the consortium is using acentral shared-storage for the blockchain ledger data.
While much of the focus for Ethereum, and other, blockchain development efforts have been in therealm of open source solutions such as BigDB and IPDB, based no doubt on their non-establishment
bias, enterprise-level blockchain users will be looking for proven enterprise-level databases such as
Microsoft® SQL, Oracle, and IBM DB2® as well as Postgres. Instead of reinventing the wheel andhaving to take significant reliability and performance hits as the technology matures, enterprisedevelopers utilize existing, proven technologies. For enterprise-level blockchain users, the focus foroff-chain data stores should be on utilizing the best existing, tested, and proved database technology
for the type of off-chain data being stored: structured, unstructured, or both.
Newer storage technologies such as NVMe will reduce processor cycle requirements for storage
thus increasing the cycles available for cryptosecurity-related calculations. Therefore, block storage
is ideal for on-chain deployments. Figure 9 shows a Non-Volatile Memory Express (NVMe) or NVMelike storage system.

Figure 9: Example NVMe-based storage system

A historical reference may serve to demonstrate the need for performance. When SAP HANA was
first introduced, it was portrayed as a memory-only database and storage was not that important. It
was later found that utilizing the proper, low-latency, high-speed storage under the SAP HANA
database improved performance by at least 30%. If performance had been a key concern from the
beginning, many projects would have been more successful.

3.1

Service-level agreements

All members of a blockchain network, Hyperledger, Ethereum, or Corda, will have to commit to aservice level agreement (SLA) specifying minimal latency and bandwidth requirements for both onchain and off-chain storage. Network consideration will have to be given about transactional logic
and efficiency to ensure optimal benefit is acquired from processor and memory resources.

14

Storage needs for blockchain technology point of view

However, the off-chain storage would be at the discretion of each member, and thus the need for anagreement to performance-based SLA between members.

4

Storage specification

Ideally, the off-chain storage is a self-contained processing and storage system capable of tiering
non-critical data and providing optimal speed for current or critical data. Sharing existing nonblockchain application data could result in sub-optimal performance and might lead to SLA violations
and ejection from the network. Any storage must also be scalable, as far as storage volume, withinvisible addition of storage capabilities. What is meant by invisible is that adding additional storage
should be completely non-impactful to existing operations and transactions. Use of a virtual machine
environment such as VMWare or Oracle VM would allow deploying identical systems to eachmember of a blockchain network, and, as long as identical hardware was deployed to host the VM
environment, similar if not identical performance would be obtained.
IBM proposes that the storage for off-chain data be architected accounting for the needs of the data,
whether it is structured, unstructured, or both. This means there is no one-size-fits-all solution, butinstead a portfolio of storage and compute options must be supplied, allowing the blockchain
developer or user to choose the best fit for their environment.

5

Processing requirements for off-chain
data stores

Unlike the blockchain peer environment itself where the processing and storage requirement will be
met by the peer resources, the off-chain processing required by the off-chain storage (whether it isenterprise or open source) will have to be met by each participant in the blockchain network. Eachparticipant needs to meet the blockchain network SLA to ensure that the performance of the overall
blockchain is not compromised. Therefore, the processing requirements of off-chain or sideDBs is a
critical factor for the overall performance of the blockchain environment.
The IBM POWER® series of processors, the latest to date being the IBM POWER9™, utilizing IBM
architecture, has shown superior performance, reliability, and security to the x86 processor-based
commodity servers.

6

Blockchain data management

Throughout this document, we repeatedly mentioned both on-chain and off-chain data for each peeron the blockchain network. Although it’s not required, properly managing all data on the blockchain
is highly recommended.

15

6.1

On-chain data management

Your peer’s on-chain data, i.e. your ledger, has built in availability in that it can be recovered fromother ledger peers that are on the same network. However, that is assuming the blockchain has
enough peers to do so. Thus, managing the on-chain data can be considered a “native” function of
the blockchain itself. However, proper data protection principles should still be followed such as
setting up backup and recovery protocols as saving copies of your own ledger will someday saveyour business. Keep in mind that recovering those copies back into the blockchain network is not aneasy task to do and would require consensus from the rest of the blockchain participants. Your onchain storage hardware may already have the right management tools to copy and protect yourledger, for example; the flashcopy tools that comes native with our IBM FlashSystem 9100 family ofarrays. Moreover, IBM's Spectrum Copy Data Management (CDM) software is an ideal way toschedule and manage these copies. This provides all the functionality for data recovery due tocorruption, sabotage or local failure. Full disaster recovery can also be enabled with the additionaluse of replication services to the cloud, whether it be the IBM Cloud™, Amazon Web Services(AWS), or Microsoft Azure.

6.2

Off-chain data management

Off-chain data store of an individual's peer and its data management is the responsibility of that peer
owner. Here lies the bigger need for proper data management processes and tools. Losing yoursupporting documentation's, i.e. your off-chain data, may result in failing audits or even being
rejected from your blockchain network. Moreover, it is extremely important to properly manage thehashes of your off-chain data, as you create and recover your backups. Note that deleting any
supporting data without going through the blockchain may be considered illegal within the blockchain
network's terms and conditions.
Given the critical nature of off-chain data, trusted and secure means of backup, recovery, andreplication must be provided. Solutions leveraging the IBM Spectrum® family of solutions, comehighly recommended.
For block and file off-chain data transfers to the cloud, IBM Spectrum Virtualize™ on the IBM Cloud
enables a true hybrid multicloud solution offering the ability to transfer data between on-premises
data centers and any IBM Spectrum Virtualize base appliance (IBM SAN Volume Controller (SVC),
IBM Storwize®, IBM FlashSystem® V9000 and VersaStack or IBM Spectrum Virtualize only and IBM
Cloud).
For unstructured data, IBM Cloud Object Storage provides an innovative, secure, and cost-effective
way to store and manage data without creating multiple copies. IBM’s groundbreaking SecureSlicetechnology distributes data slices across storage systems for security and protection. This uniqueapproach combines encryption, erasure coding, and information dispersal of data to multiple
locations for protection, without complex or expensive copies. The service is continuously available
and can even tolerate catastrophic regional outages without downtime or the need for customer
intervention.
To achieve similar dispersed storage on other leading clouds, customers would have to invoke areplication technique, creating a second copy of the data in a separate region, which would then16

Storage needs for blockchain technology point of view

have to be managed. IBM Cloud Object Storage does not require replication techniques or complex
configurations to make it fast and efficient to meet cloud data storage needs.
Some users might want to use some sort of stand-alone utility to interact with their storage. As the
Cloud Object Storage API supports the most common set of S3 API operations, many S3-compatible
tools can also connect to Cloud Object Storage using HMAC credentials.
Some examples include file explorers such as Cyberduck or Transmit, backup utilities such as
CloudBerry or Duplicati, command line utilities such as s3cmd or Minio Client, and many others.

17

7

Does the source blockchain matter?

All blockchains that will be used for tokenized, non-frangible data, will require off-chain storage.
When the ERC721 standard was released in November 2017, one of the first uses was for
Cryptokitties. Cryptokitties are stylized cat pictures that contain a DNA code for their features.
Cryptokitties can be mated to produce a unique offspring based on the DNA of the parents and a
proprietary mixing algorithm. After the introduction, the traffic for Cryptokitties crashed the Ethereum
network. If more robust storage and planning for off-chain storage and server assets had been used,
they would have not had this issue. Within a few months, the Cryptokitties were generatingtransactions equivalent to USD16 million dollars and had grown to over 600,000 distinct
Cryptokitties. While Cryptokitties itself was a great success, the underlying infrastructure failed.
While the Cryptokitties example seems frivolous, it does show that you must always plan forsuccess.

Figure 10: Cryptokitties was the first success for Ethereum ERC721 blockchain

Whether it is ERC721 data in Ethereum, pictures of diamonds in Hyperledger or whatever comes
down the pike for other blockchain specifications, off-chain storage of some kind will be required.
Therefore, this specification is good, no matter the source of the off-chain data.

18

Storage needs for blockchain technology point of view

8

Summary and recommendations

High-performance processors to calculate and confirm the needed crypto-hash and signature
verifications, as well as handling off-chain database processing requirements, will necessitate theuse of IBM System Z® LinuxONE or POWER9 processor-based computing assets.
When it comes to blockchain storage, backup, recovery, and replication services must be robust,tested, and trusted and must provide enterprise-level performance and reliability. Utilization ofcontainerized, virtual environments will ensure performance when deployed on identical or more
efficient hardware platforms.
In view of this need for tiered, high performance, self-contained storage, IBM offers a variety ofstorage products (both hardware- and software-defined storage) that can meet the on-chain and offchain needs for blockchain. The IBM Storwize product, such as IBM FlashSystem 9100, delivers
performance (NVMe), security (encryption), and controls (SVC) to meet the various on-chain
multicloud peer requirements. IBM also offers a variety of Storage that can meet, and sometimes
exceed, the off-chain data store and data management requirements for a blockchain network. For
additional information, please visit our IBM Storage Solutions for Blockchain (www) page.

19

REFERENCES
Figure 4 Source: IDC's Worldwide Semiannual Blockchain Spending Guide, 2H17 (August 2018)20

Storage needs for blockchain technology point of view®
© Copyright IBM Corporation 2018
IBM United States of America
Produced in the United States of America
US Government Users Restricted Rights - Use, duplication or disclosure restricted by GSA ADP Schedule Contract withIBM Corp.
IBM may not offer the products, services, or features discussed in this document in other countries. Consult your local IBM
representative for information on the products and services currently available in your area. Any reference to an IBM
product, program, or service is not intended to state or imply that only that IBM product, program, or service may be used.
Any functionally equivalent product, program, or service that does not infringe any IBM intellectual property right may be
used instead. However, it is the user's responsibility to evaluate and verify the operation of any non-IBM product, program,or service.
IBM may have patents or pending patent applications covering subject matter described in this document. The furnishing of
this document does not grant you any license to these patents. You can send license inquiries, in writing, to:IBM Director of Licensing
IBM Corporation
North Castle Drive
Armonk, NY 10504-1785
U.S.A.
The following paragraph does not apply to the United Kingdom or any other country where such provisions areinconsistent with local law:
INTERNATIONAL BUSINESS MACHINES CORPORATION PROVIDES THIS PAPER “AS IS” WITHOUT WARRANTY OF
ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OFNON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Some states do not allow
disclaimer of express or implied warranties in certain transactions, therefore, this statement may not apply to you.
This information could include technical inaccuracies or typographical errors. Changes may be made periodically to theinformation herein; these changes may be incorporated in subsequent versions of the paper. IBM may make improvements
and/or changes in the product(s) and/or the program(s) described in this paper at any time without notice.
Any references in this document to non-IBM Web sites are provided for convenience only and do not in any manner serveas an endorsement of those Web sites. The materials at those Web sites are not part of the materials for this IBM productand use of those Web sites is at your own risk.
IBM may have patents or pending patent applications covering subject matter described in this document. The furnishing of
this document does not give you any license to these patents. You can send license inquiries, in writing, to:IBM Director of Licensing
IBM Corporation
4205 South Miami Boulevard
Research Triangle Park, NC 27709 U.S.A.
All statements regarding IBM's future direction or intent are subject to change or withdrawal without notice, and represent
goals and objectives only.
This information is for planning purposes only. The information herein is subject to change before the products describedbecome available.
If you are viewing this information softcopy, the photographs and color illustrations may not appear.

21

Trademarks
IBM, the IBM logo, and ibm.com are trademarks or registered trademarks of International Business Machines Corporation in
the United States, other countries, or both. If these and other IBM trademarked terms are marked on their first occurrence inthis information with a trademark symbol (® or ™), these symbols indicate U.S. registered or common law trademarks
owned by IBM at the time this information was published. Such trademarks may also be registered or common law
trademarks in other countries. A current list of IBM trademarks is available on the web at "Copyright and trademark
information" at http://www.ibm.com/legal/copytrade.shtml.
Linux is a registered trademark of Linus Torvalds in the United States, other countries, or both.
Microsoft, Windows, Windows NT, and the Windows logo are trademarks of Microsoft Corporation in the United States,
other countries, or both.
Intel, Intel logo, Intel Inside, Intel Inside logo, Intel Centrino, Intel Centrino logo, Celeron, Intel Xeon, Intel SpeedStep,
Itanium, and Pentium are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the UnitedStates and other countries.
UNIX is a registered trademark of The Open Group in the United States and other countries.
Java and all Java-based trademarks and logos are trademarks or registered trademarks of Oracle and/or its affiliates.
Other company, product, or service names may be trademarks or service marks of others.

22