HA Solutions for SAP HANA using SAPHanaSR-angi #
SUSE Linux Enterprise Server for SAP applications is the leading Linux platform for SAP HANA, SAP S/4HANA and SAP NetWeaver. Two of the key components of SLES for SAP are SUSE Linux Enterprise High Availability (SLE HA) and resource agents (RAs). SLE HA provides Pacemaker, an open-source cluster framework. The resource agents manage automated failover of SAP HANA system replication, S/4HANA ASCS/ERS, and NetWeaver ASCS/ERS.
This document provides an overview of the High Availability solutions that SUSE supports for SAP HANA system replication
on SLES for SAP 15 and 16, using the SAPHanaSR-angi
resource agent. New solutions will be added when they become available.
Copyright © 2023–2026 SUSE LLC and contributors. All rights reserved.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or (at your option) version 1.3; with the Invariant Section being this copyright notice and license. A copy of the license version 1.2 is included in the section entitled “GNU Free Documentation License”.
For SUSE trademarks, see https://www.suse.com/company/legal/. All third-party trademarks are the property of their respective owners. Trademark symbols (®, ™ etc.) denote trademarks of SUSE and its affiliates. Asterisks (*) denote third-party trademarks.
All information found in this book has been compiled with utmost attention to detail. However, this does not guarantee complete accuracy. Neither SUSE LLC, its affiliates, the authors nor the translators shall be held liable for possible errors or the consequences thereof.
1 Support statement #
1.1 Supportability definition #
| Category | Definition |
|---|---|
| Mandatory | De facto, must be implemented this way. |
| Supported | Supported, with a published configuration guide. |
| Supported but undocumented | Supported, but a configuration guide is not published. SUSE will accept bug reports and fix code, if needed. |
| Supported with consulting PoC | Support is possible if the consulting PoC proves to be working. |
| Non-supported | Not supported or not applicable. |
| Planned | On the roadmap to be tested and supported. |
| Legacy | Only supported for older release legacy systems. |
1.2 Infrastructure support #
The infrastructure can be on-premises, physical, virtual or in public cloud. The infrastructure must be supported by both SAP and SUSE Linux Enterprise High Availability so that important functions like fencing and virtual IP are supported.
Public cloud deployment usually needs additional documentation focusing on the cloud-specific implementation details. Check the documentation provided by the respective public cloud vendor.
The support details for SUSE's High Availability solutions for SAP and the support process for each public cloud vendor are defined in the following SAP Notes:
| Company | SAP Note |
|---|---|
| SUSE | SAP Note 1763512: Support details for SUSE Linux Enterprise for SAP Applications - HA Solution for SAP NetWeaver and SAP S/4HANA |
| Microsoft Azure | SAP Note 2513384: SUSE Linux Enterprise Server for SAP applications on Azure |
| AWS | SAP Note 1656099: SAP Applications on AWS: Supported DB/OS and AWS EC2 products |
| Google Cloud | SAP Note 2456432: SAP Applications on Google Cloud: Supported Products and GCP VM types |
For more details, see the SUSE knowledgebase article SLES for SAP - How To Engage SAP and SUSE to address Product Issues.
If necessary, all documented SUSE Linux Enterprise High Availability scenarios can run the SAP workload while the High Availability cluster is temporarily disabled.
1.3 Supported SUSE software versions #
This document applies to SUSE Linux Enterprise Server for SAP applications 16 and 15.
The general SUSE software lifecycle applies for the described scenarios. See the SUSE lifecycle page for details:
https://www.suse.com/lifecycle/#suse-linux-enterprise-server-for-sap-applications-16
https://www.suse.com/lifecycle/#suse-linux-enterprise-server-for-sap-applications-15
2 Overview of HA solutions for SAP HANA system replication #
2.1 Overview of SAP HANA system replication #
SAP HANA system replication (HSR) provides the ability to copy and continuously synchronize an SAP HANA database to a secondary location in the same or another data center. SAP HANA system replication is implemented between two different SAP HANA systems with the same number of active nodes. After system replication is set up between the two systems, it replicates all the data from the primary SAP HANA system to the secondary SAP HANA system (initial copy). After this, any logged changes in the primary system are also sent to the secondary system.
If the primary SAP HANA system fails, the system administrator must perform a manual takeover. Takeover can be performed using SAP HANA Cockpit or the command line. Manual failover requires continuous monitoring and could lead to higher recovery time. To automate the failover process, SUSE Linux Enterprise High Availability can be used. Using High Availability for the takeover process helps customers achieve service-level agreements for SAP HANA downtime by enabling faster recovery without any manual intervention.
Multiple SAP HANA High Availability scenarios are supported based on SAP HANA system replication. For variations, contact SUSE to discuss defining a PoC for a scenario that is not mentioned in the documentation.
You can use SAP HANA Fast Restart on RAM-tmpfs and SAP HANA on persistent memory if they are transparent to the High Availability cluster. On SLES for SAP 16, virtual persistent memory (vPMEM) is still supported, but Physical PMEM (Intel Optane) is not supported.
SAP HANA Native Storage Extension (NSE) is supported in High Availability solutions for automated SAP HANA system replication in both Scale-up and Scale-out. This feature does not change the SAP HANA topology or interfaces to the High Availability cluster. However, unlike SAP HANA NSE, the HANA Extension Nodes do change the topology and are therefore not currently supported by SUSE Linux Enterprise High Availability. Refer to the SAP documentation for details of SAP HANA NSE and its functional restrictions.
2.2 Resource agents for automated SAP HANA system replication #
To provide a streamlined High Availability solution, SUSE is evolving its SAP HANA clustering infrastructure
away from legacy, decade-old code bases. The traditional framework required administrators to
manage two distinct resource agents: SAPHanaSR for scale-up topologies
and SAPHanaSR-ScaleOut for scale-out topologies. This architectural
division is being consolidated into SAPHanaSR-angi (Advanced Next
Generation Interface), a unified, single code base engineered to sustain reliable High Availability for
SAP HANA over the next decade.
This evolution drastically reduces operational complexity by introducing an identical software
package and highly similar configuration models regardless of the underlying scale-up or
scale-out environment. Although the classic resource agents will remain supported for the
entire lifetime of SLES for SAP 15, SAPHanaSR-angi is also
available in SLES for SAP 15 SP4+. This is the recommended choice for all new deployments,
and will completely replace the classic resource agents as the default standard in
SLES for SAP 16.
Along with optimizations like faster takeover capabilities, SAPHanaSR-angi
also supports a live, in-place upgrade from the classic resource agents, without requiring any
SAP HANA downtime.
| OS release | HANA scale-up | HANA scale-out |
|---|---|---|
| SLES for SAP 16 | SAPHanaSR-angi only | SAPHanaSR-angi only |
| SLES for SAP 15 |
|
|
2.3 Notation formula #
This table shows the notation formula used in the following sections to describe the different configurations for SAP HANA system replication.
| Notation | Definition |
|---|---|
| [ ] | Cluster running |
| { } | Cluster DR passive |
| A B C D | Master nameserver node |
| a b c d | Worker node |
| _ | Standby node |
| x | XSA node |
| => | Sync, syncmem replication |
| -> | Async replication |
| ' | Primary IP address |
| " | Secondary IP address |
2.4 Common configurations for automated SAP HANA system replication #
Below is a summary of the most common and newly supported configurations for
SAPHanaSR-angi. For the complete support matrix for all
supported topologies, see Section 3, “Support matrix for automated SAP HANA system replication”.
SAPHanaSR-angi configuration variants
SAPHanaSR-angi introduces two configuration variants that allow
administrators to choose the failover behavior that best aligns with their operational and
availability requirements. While both variants provide High Availability for SAP HANA, they differ in how
they respond to failures and balance recovery speed against service stability.
Progressive variant: Optimized for rapid recovery by proactively fencing the affected site when critical SAP HANA or file system failures are detected, enabling fast and reliable failover. This is the recommended option for most new deployments, particularly in cloud and performance-optimized environments.
Conservative variant: Prioritizes service stability by attempting to recover SAP HANA locally before fencing cluster nodes, reducing the likelihood of unnecessary fencing. This variant is best suited for traditional on-premises environments where maximizing local recovery is preferred over the fastest possible failover.
- Scale-up, performance-optimized [A' => B], including read-enabled on the secondary site [A' => B"]
- Figure 2: Scale-up, performance-optimized #
In the performance-optimized scenario, an SAP HANA RDBMS site A is synchronizing with an SAP HANA RDBMS site B on a second node. As the SAP HANA RDBMS on the second node is configured to preload the tables, the takeover time is typically very short.
Read access can be allowed on the secondary site. To support this read-enabled scenario, a second virtual IP address is added to the cluster and bound to the secondary role of the system replication.
- SAP HANA XSA stand-alone [xB <= A'x']
- Figure 3: SAP HANA XSA stand-alone #
SAP HANA XSA stand-alone is supported in the cluster by deploying XSA worker nodes alongside the SAP HANA master/worker nodes. Dedicated IP addresses are assigned to the primary XSA worker as well as the primary HANA master/worker node to ensure consistent service access. SAP HANA system replication is enabled between the two HANA master/worker nodes, while a shared NFS file system maintains the XSA work directory across both sites to support seamless failover. The SUSE Linux Enterprise High Availability solution for SAP XSA stand-alone is based on the High Availability architecture for SAP HANA scale-out ERP, with the
SAPHanaSR-angiProgressive variant. - DR region with passive cluster (Technology Preview) {D <= C} <- [A' => B]
- Figure 4: DR region with passive cluster #
This deployment consists of a production region protected by a High Availability cluster using the
SAPHanaSR-angiscale-up performance-optimized with Progressive variant. A separate disaster recovery (DR) region is equipped with a passive High Availability cluster to support recovery operations. In the event of a disaster, failover to the DR region is performed through a manual DR takeover process. There is no automated cluster takeover between the production and DR sites.
3 Support matrix for automated SAP HANA system replication #
3.1 Automated SAP HANA system replication in HANA scale-up #
| SAP HANA scale-up configuration | Status |
|---|---|
| Performance-optimized | Supported |
| Performance-optimized, second site read-enabled | Supported |
| Performance-optimized, Multi-Target SR, third site NOT managed by the cluster | Supported |
| Performance-optimized, Multi-Target SR, third site in passive cluster (Tech Preview) | Supported, but undocumented |
| Performance-optimized, Multi-SID in one cluster (MCOS) | Supported, but undocumented |
| Performance-optimized, with S/4 ENSA2 in the same cluster | Supported, but undocumented |
| Performance-optimized, with S/4 ENSA1 in the same cluster (only on SLES for SAP 15) | Supported, but undocumented |
| Performance-optimized, with stand-alone S/4 Application Server in the same cluster | Supported, but undocumented |
| Cost-optimized | Supported, but undocumented |
| Cost-optimized, Multi-Target | Non-supported |
| Performance-optimized, Multi-Target SR, third site in the same cluster | Non-supported |
| Two performance-optimized clusters connected | Non-supported |
3.2 Automated SAP HANA system replication in HANA scale-out #
| SAP HANA scale-out configuration | Status |
|---|---|
| Performance-optimized, up to 12 nodes, NO standby (BW) | Supported |
| Performance-optimized, up to 4 nodes, second site read-enabled (ERP) | Supported |
| Performance-optimized, Multi-Target SR, third site NOT managed by the cluster | Supported |
| Performance-optimized, up to 30 nodes including standby (BW) | Supported, but undocumented |
| Performance-optimized, up to 4 nodes, with stand-alone XSA, NO standby | Supported, but undocumented |
| Performance-optimized, Multi-Target SR, third site in the same cluster | Non-supported |
| Performance-optimized, Multi-SID | Non-supported |
| Cost-optimized | Non-supported |
| Two performance-optimized clusters connected | Non-supported |
4 HANA database HA/DR provider hook scripts #
SUSE provides several hook scripts to enhance the integration between SAP HANA and the
SUSE Linux Enterprise High Availability cluster. This section describes the HA/DR provider hook scripts for the
SAPHanaSR-angi resource agent. The SUSE best practice configuration
guides explain how to use and configure these hooks.
| Script | Usage |
|---|---|
susHanaSR.py | Mandatory for data integrity in case of cluster sr_takeover |
| susTkOver.py | Protects from data inconsistency caused by manual sr_takeover |
| susChkSrv.py | Avoids downtime caused by local indexserver restart |
| susCostOpt.py | Used in scale-up cost-optimized to handle secondary site in case of cluster sr_takeover |
| HA/DR provider hook script | Scale-up cost-optimized | Scale-up performance-optimized | Scale-out performance-optimized |
|---|---|---|---|
| susHanaSR.py | Mandatory | Mandatory | Mandatory |
| susTkOver.py | Supported | Supported | Supported |
| susChkSrv.py | Non-supported | Supported | Supported |
| susCostOpt.py | Mandatory | Not Applicable | Not Applicable |
5 Upgrading to SAPHanaSR-angi #
Existing SAP HANA High Availability clusters can be upgraded from the legacy
SAPHanaSR or SAPHanaSR-ScaleOut
resource agents to SAPHanaSR-angi without requiring SAP HANA downtime.
The in-place upgrade replaces the legacy resource agents and provider scripts with the new
SAPHanaSR-angi components while preserving the existing cluster and
SAP HANA system replication configuration, minimizing service disruption and avoiding a full cluster rebuild.
The environment must meet the documented prerequisites and the upgrade must be carefully planned. SUSE recommends the following approach:
Validate the cluster configuration.
Back up the existing configuration.
Test the upgrade procedure in a non-production environment.
Use the upgrade guidance and automation scripts to generate a cluster-specific runbook before performing the production upgrade.
For more information, see https://www.suse.com/c/how-to-upgrade-to-saphanasr-angi/.
6 Documentation and configuration guides #
Refer to the official Web sites for up-to-date documentation and configuration guides:
- SUSE Best Practices
SUSE Best Practices: SAP applications on SUSE Linux 16: https://documentation.suse.com/sbp/sap-16/
SUSE Best Practices: SAP applications on SUSE Linux Enterprise 15: https://documentation.suse.com/sbp/sap-15/
- SAPHanaSR-angi
What is
SAPHanaSR-angi?: https://www.suse.com/c/what-is-saphanasr-angi/What are
SAPHanaSR-angiconfiguration variants?: https://www.suse.com/c/what-are-saphanasr-angi-configuration-variants/How to upgrade to
SAPHanaSR-angi: https://www.suse.com/c/how-to-upgrade-to-saphanasr-angi/SUSE HA for SAP HANA scale-up cost-optimized improved using ANGI: https://www.suse.com/c/suse-ha-for-sap-hana-scale-up-cost-optimized-improved/
Man pages for
SAPHanaSR-angi: https://manpages.opensuse.org/Leap-16.0/SAPHanaSR-angi/index.html (For reference only. For the latest information, view the man pages on your SLES for SAP system.)
- Public cloud providers
Microsoft Azure: https://azure.microsoft.com/en-us/solutions/sap/#documentation
Google Cloud: https://cloud.google.com/solutions/sap/
A GNU licenses #
This appendix contains the GNU Free Documentation License version 1.2.
GNU Free Documentation License #
Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc. 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
0. PREAMBLE #
The purpose of this License is to make a manual, textbook, or other functional and useful document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or non-commercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.
This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.
We have designed this License to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.
1. APPLICABILITY AND DEFINITIONS #
This License applies to any manual or other work, in any medium, that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The "Document", below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as "you". You accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law.
A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.
A "Secondary Section" is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.
The "Invariant Sections" are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none.
The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words.
A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup, or absence of markup, has been arranged to thwart or discourage subsequent modification by readers is not Transparent. An image format is not Transparent if used for any substantial amount of text. A copy that is not "Transparent" is called "Opaque".
Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML, PostScript or PDF designed for human modification. Examples of transparent image formats include PNG, XCF and JPG. Opaque formats include proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML, PostScript or PDF produced by some word processors for output purposes only.
The "Title Page" means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, "Title Page" means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text.
A section "Entitled XYZ" means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language. (Here XYZ stands for a specific section name mentioned below, such as "Acknowledgements", "Dedications", "Endorsements", or "History".) To "Preserve the Title" of such a section when you modify the Document means that it remains a section "Entitled XYZ" according to this definition.
The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document. These Warranty Disclaimers are considered to be included by reference in this License, but only as regards disclaiming warranties: any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License.
2. VERBATIM COPYING #
You may copy and distribute the Document in any medium, either commercially or non-commercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.
You may also lend copies, under the same conditions stated above, and you may publicly display copies.
3. COPYING IN QUANTITY #
If you publish printed copies (or copies in media that commonly have printed covers) of the Document, numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects.
If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages.
If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a computer-network location from which the general network-using public has access to download using public-standard network protocols a complete Transparent copy of the Document, free of added material. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.
It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document.
4. MODIFICATIONS #
You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:
Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission.
List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has fewer than five), unless they release you from this requirement.
State on the Title page the name of the publisher of the Modified Version, as the publisher.
Preserve all the copyright notices of the Document.
Add an appropriate copyright notice for your modifications adjacent to the other copyright notices.
Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below.
Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice.
Include an unaltered copy of this License.
Preserve the section Entitled "History", Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled "History" in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence.
Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the "History" section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission.
For any section Entitled "Acknowledgements" or "Dedications", Preserve the Title of the section, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein.
Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles.
Delete any section Entitled "Endorsements". Such a section may not be included in the Modified Version.
Do not retitle any existing section to be Entitled "Endorsements" or to conflict in title with any Invariant Section.
Preserve any Warranty Disclaimers.
If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles.
You may add a section Entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various parties--for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.
You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.
The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.
5. COMBINING DOCUMENTS #
You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers.
The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.
In the combination, you must combine any sections Entitled "History" in the various original documents, forming one section Entitled "History"; likewise combine any sections Entitled "Acknowledgements", and any sections Entitled "Dedications". You must delete all sections Entitled "Endorsements".
6. COLLECTIONS OF DOCUMENTS #
You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.
You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.
7. AGGREGATION WITH INDEPENDENT WORKS #
A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an "aggregate" if the copyright resulting from the compilation is not used to limit the legal rights of the compilation's users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document.
If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document's Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.
8. TRANSLATION #
Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail.
If a section in the Document is Entitled "Acknowledgements", "Dedications", or "History", the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.
9. TERMINATION #
You may not copy, modify, sublicense, or distribute the Document except as expressly provided for under this License. Any other attempt to copy, modify, sublicense or distribute the Document is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance.
10. FUTURE REVISIONS OF THIS LICENSE #
The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See https://www.gnu.org/copyleft/.
Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation.
ADDENDUM: How to use this License for your documents #
Copyright (c) YEAR YOUR NAME. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License”.
If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the “with...Texts.” line with this:
with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.
If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.


