How to track OSS?

ホーム＞要員育成情報＞How to track OSS?

SI Forum How to track OSS? (Japanese Version)

Everyone feels to get lonely out new culture, or new platform.
Linux/OSS is not an exception in this feeling. However, there will be the ropes of handling, or some know-how to make full use of fast-growing and ever-changing information.
We believe that such tips or know-how will be useful in understanding and safer or more effective use of OSS/Linux. Here is an easy-to-follow explanation about the common sense advice as a Linux/OSS engineer, in the form of a dialogue between Lucky who is an assumed expert of OSS/Linux and Will who is an assumed three-year experience of Windows engineer.

  1. CHAPTER-1: OSS IS REALLY USABLE!
    1. Information of OSS
    2. Merit of OSS
    3. Reduce of TCO
    4. Security of OSS
    5. Is publication of source code weak point?
    6. Intellectual property of OSS
    7. Distribution of our own making and points of concern:
  2. CHAPTER-2: SURE UTILIZATION AND
    1. Hardware used for OSS:
    2. Distribution of Linux
    3. Function of Linux Distribution
    4. OSS middleware and Commercial middleware
    5. Sizing information of Linux-OSS
    6. Operation management tool of Linux system and backup software
    7. Security of Linux system
    8. Development environment of Linux
    9. SI Agreement of Linux-OSS
  3. CHAPTER-3: HOW TO BUILD AN OSS-BASED SYSTEM
    1. Concept and terminology of Linux and Windows:
    2. Installation of Linux
    3. Copy of Linux distribution
    4. Reason for pay support service
    5. Hint for Linux support
    6. Request of commercial support
    7. Troubles of application development and/or system performance
  4. CHAPTER-4: OPEATION OF OSS
    1. How to solve troubles of Linux system:
    2. Maintenance activity of your customer's system
    3. Utilization of Errata
    4. Possible customization of Linux:
    5. Utilization of Update/SP
    6. Implementation of Version-up

CHAPTER-1: OSS IS REALLY USABLE!

Information of OSS:

Will: Lucky, I have three-year experience in making Windows systems. I have believed that MS (Microsoft) could well take good care of giving us flood of data by MSDN (Microsoft Developers Network), etc. But what about the case of Linux or OSS? How can we get access to such information?
Lucky: If you intend to become a professional engineer as a system integrator, you can't live long only depending on the information supplied by commercial vendors. In OSS world, all kinds of information are open to public and shared in the world. Only if you know how to take a proper step of OSS, you can skill up yourself much better than living within Windows world. You need to work your way to find useful information by yourself.

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Merit of OSS:

Will: But I think customers do not necessarily dare to select Linux or OSS. How can I explain to our customers when I recommend them to make their systems by OSS?
Lucky: Do you want to know the merit of OSS? OK, there are too much! You had better to point out only several merits depending on the circumstances of the customers. OSS has such merits that:
1. users are not locked in the particular products or vendors, which enables to maintain competition among products and services. You can expect big difference in cost-effectiveness in the long run;
("locked-in" means: if a certain system is adopted, then the following system necessarily result in the same one.)
2. all technologies including source code are shared worldwide, which is going to be a common sense, i.e., common basic technology among engineers including new graduates. This also means it is easier to secure engineers withouｔ bearing a heavy burden for additional education
3. It is also easier to secure mutual connectivity or portability between the systems installed Linux with same source code, or between OSS middlewares.
4. recent engineers mostly tend to utilize Linux or OSS environment to develop both hardware and software, which means new technology will be developed based on Linux/OSS platform from now on, just like the former situation of UNIX;
5. rapid growth of Linux and OSS in the world encourages corporate customers to consider their investment in using Linux/OSS as the first priority, particularly in the field of human resources, hardware, or software.

You can easily find out various information in the Web sites of such organizations as OSDL, Japan OSS Promotion Forum*1 , Linux distributors, or platform vendors, why they promote Linux/OSS platform in their own words and reasons. Also Japanese government proclaims their policy intending to promote Linux/OSS*2, aiming to eliminate locked-in situation in the particular products and to boost software industry regarding OSS as a spring board.
*1 http://www.ipa.go.jp/software/open/forum/
*2 http://www.kantei.go.jp/jp/singi/it2/kettei/050224/050224pac.html

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Reduce of TCO (Total Cost of Ownership):

Will: Have you forgotten the merit of reducing TCO? You don't think customers seem to be particularly interested in the direct cost rather than long-term advantages, do you?
Lucky: Of course, in a simple system such as Web server or mail server with comparatively small applications, an IA (Intel Architecture) server with Linux is much cheaper than a RISC server with UNIX, and it is even cheaper than the Windows server properly considering CALs (Client Access Licensing). But according to the importance by increase of business application software, the criterion shifts from TCO to ROI (Return On Investment), i.e., what services or jobs the system can do for the client. You can also refer to "the TCO guide of open source software" compiled by Japan OSS Promotion Forum*3*3, which describes how to maintain higher operating ratio of the system, or to utilize business applications as long as possible.
*3 http://www.ipa.go.jp/software/open/forum/business/download/oss_tcoguide.pdf

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Security of OSS:

Will: Is it true that Linux is stronger in security? I think it seems natural that crackers tend to attack Windows more, because they are used much more in the world. Does it sound reasonable that less attack to Linux does not necessarily mean that Linux is securer than Windows?
Lucky: By the way, guys who attack security of the system are usually called 'cracker', while people who contribute to OSS community are favorably called 'hacker.'
Even when limiting the discussion to computer vulnerability (virus infection and illegal entry), Regarding to security level, it is not so easy to compare such judgement that which platform is securer or not in terms of infection by virus or easiness of illegal entry. In 1990s when Microsoft products prevailed in the Internet world, there occurred various problems in the quality of products as well as various network functions which were enable as default, but these problems have been improved now. Also, business model of Microsoft may cause crackers in the world to attack Windows systems.
On the other hand, Linux community shows great enthusiasm for debugging of Linux; if any security bugs in Linux were found, systematic measures would be taken at once by the activities of worldwide engineers trying to find the best way to solve. To be modest, we could say that Linux would be less frequently attacked by crackers at the moment. It is quite sure in Linux that no virus exists misusing Outlook mailing system. Obviously, crackers may attack any weak points existing in the computer system functions such as in mailing system or file exchange.
Thus, less number of security holes do not necessarily means it is securer system. Security issues continue endlessly according to expansion of computer applications. We could not say that even Linux/OSS system would be absolutely safe.

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[Is publication of source code weak point?:]

Will: Conversely, is it plausible that openness of Linux code may help crackers can study security holes, which may cause more frequent security attack in Linux? Is there such risk as crackers might embed harmful code into Linux?
Lucky: There may be such a discussion as worrying about openness of source code might cause security risk. But compared to dependence on the black box tests in the proprietary software through crackers, the method of open approach by publicizing source code and getting worldwide engineers' reviews and tests in proving security is much quicker and effective in solving security bug problems.
Furthermore, the source code of Linux or any other OSS, nobody can revise source code freely, but only authorized specialists named source code maintainers are to review code strictly, and there is no way questionable code is embedded in OSS.
Regarding this issue, you can refer a good article in IBM System Journal: "Open-source versus proprietary software: Is one more reliable and secure than the other?"*4
*4 http://www.research.ibm.com/journal/sj/442/boulanger.pdf

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Intellectual property of OSS:

Will: think that OSS development community consists of various people who might infringe intellectual property such as copyright or patent right. What if corporate users or government were brought a lawsuit, their social credit might have fallen down?
Lucky: Such campaign seems to be propagated by the people who want to prevent diffusion of OSS, doesn't it? Regarding this issue, I would mention followings:
1. It is true that if OSS contains any infringement of intellectual property right, it may cause troubles to users, but the situation is same with the case of proprietary software. License holders usually resort legal action to the upstream vendors rather than to each downstream end-user, because the legal action will not be effective if they want to sue one by one. In US, it is widely known that SCO filed a suit against users (Daimler-Chrysler and AutoZone), but the reason of the suit was not the use of Linux itself, but the management of UNIX source code, or the usage of converting tool of UNIX-Linux and so forth. Even if there were infringement of intellectual property in OSS, it could highly unlikely that the end-users would be filed a suit.
2. Developers and source code maintainers of the development communities of famous OSS used worldwide keep a close watch on infringement of intellectual property right. Moreover various technical specialists contribute the communities and discuss the legal issues more frequently than ordinary corporations. You need not worry about legal issues about such well-known OSS not less than ordinary proprietary software.
3. If infringement of intellectual property right occurred, the well-known OSS widely used in the world could immediately respond by revising the code in question getting full support of technical specialists. Nowadays, owing to various corporations are involved in OSS, and if such situation happened, they would take collaborative actions with development community, trying to revise code quickly in proactive manners.
4. But even though, users of OSS need to understand that they cannot lay the responsibility of infringement of intellectual property right on OSS development community. It is the condition that users of certain OSS must approve such ways of development by the OSS community if and when they want to become users of said OSS. If the users could not approve it, they would have no means of using OSS. And if OSS or OSS community were exposed to the menace of such infringement of intellectual property right, users could be expected to support the stance of OSS community. Even if you suffered from any peculiar suit, which would be nothing of eclipse of your honor, but you could expect various supports from all over the world as long as you are a fair user of OSS. Linux Legal Defense Fund*5 of OSDL was established on the occasion that SCO had sued Linux users. Similar safety net will be prepared from now onward.

Regarding to the intellectual property right issues surrounding OSS, you can refer various information compiled by Japan OSS Promotion Forum: "Research report of legal risks related to business use of open source software." *6
*5 http://www.osdl.org/about_osdl/legal/lldf
*6 http://www.ipa.go.jp/software/open/forum/business/download/oss_risk.pdf

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Distribution of our own making and points of concern:

Will: I am making a remarkable tool using OSS related to my own project. But I am worrying about whether we should sell it to our customer. Someone advises me it may be too risky because of difficult rule called GPL.
Lucky: There is no problem as long as you use it in your office, but if you consider to give it or sell it commercially to the third party, you must consult your legal department about what to do, including warranty condition. Also you should familiarize yourself with the basic rules of GPL, etc. which would not be so difficult to understand as a aiming real professional engineer.
Regarding to the tool you mentioned, you should know the difference of license terms according to the particular OSS such as Tomcat, JBoss, PHP, or Eclipse. Generally speaking, commercial usages are allowed. But it is also responsible for you to check and comply with the license terms of particular OSS you used. You must be always sensitive about violation of rules which might cause social responsibility to the corporation you belong to.
In particular, GPL is referred to as a 'propagating' license (because the GPL of one product propagate a second and make it GPL.) as mentioned in the report of OSS Promotion Forum. This is important in the case of calling OS functions of Linux in C language program; the license terms of the called OS functions (=Library functions) are applicable to the whole tools.
FSF (Free Software Foundation) views that this propagating characteristic of GPL is applicable not only to static linkage, but also to dynamic linkage. This means we must be more explicit about all license terms of library functions to which the tool refers, by checking which is GPL (General Public License), or LGPL (Lesser GPL), or BSD (Berkley Software Distribution). You must be more careful about GPL library when you want to use them.
But most of the function libraries such as glibc are based on the licenses of LGPL or BSD, which does not require to publicize the source code. There are still other rules of LGPL or BSD, to which you must pay attention when you intend to transfer to the third party. I have checked so far the following category:
LGPL: glibc, gnome-libs, and mostly others,
BSD or similar to BSD: X11, tiff, etc.,
GPL or similar to GPL: Qt.

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CHAPTER-2: SURE UTILIZATION AND CONFIDENT PROPOSAL

Hardware used for OSS:

Will: Lucky, I am considering to propose Linux/OSS based system to my customer. How many choices are there of hardware? What is your recommendation for the hardware installed Linux?
Lucky: As Linux is basically usable of IA (Intel Architecture) server on which it is originally developed, the same hardware for Windows is also available. Some vendors chose RISC server or mainframe server with Linux. So, customers are guaranteed to use quite wide range of options of hardware just like those for Windows server, or even more than that. You can choose any hardware from worldwide vendors and you are free to change to other vendors at any time. The points of criterion of hardware are, I would say, price, performance, quality, and support. IA servers which many vendors supply are always in highly competitive situation. To use Linux means to make no-vender-lock-in.
SIers' Forum (SI-Forum) *7 of OSDL just published the list of Linux supporting status quo, but it is also necessary for you to check the hardware by yourselves.
*7 http://www.osdl.jp/modules/tinyd3?id=11

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Distribution of Linux:

Will: I found there are many Linux distributors. Can you recommend to me preferable distributors?
Lucky: There is a list of server models and Linux distribution, mentioning feasible combinations with yes/no matrix, which you can choose best matching of hardware and distributor. For business use, I would recommend to you such Linux distributions suitable for mission-critical systems as RHEL (Red Hat Enterprise Linux), SLES (SUSE Linux Enterprise Server), or ML (Miracle Linux). These distributors provide customers with cost effective fee-paying support services corresponding to their Linux distribution. The features of such distribution are:
For business use, I would recommend to you such Linux distributions suitable for mission-critical systems as RHEL (Red Hat Enterprise Linux), SLES (SUSE Linux Enterprise Server), or ML (Miracle Linux). These distributors provide customers with cost effective fee-paying support services corresponding to their Linux distribution. The features of such distribution are:
1. They are using more stable Linux kernel which Linux community published half or one year ago. They dare to avoid installing challengeable the latest version of Linux kernel.
2. Linux they commit has relatively long cyclic period version up with one or one and half year cycle, and the long support period continues 5-7 year.
3. Binary compatibility of applications is guaranteed within the same version.
4. Therefore, various worldwide commercial middlewares are guaranteed to be ported to such stable Linux distributions.

In my company, we usually select a certain Linux distribution which has variety of middlewares in order that our engineers can share technical information of the distribution, unless the client specifies other distribution.
Linux distributions which the community packaged like Debian or Fedora are cheaper in price but would be difficult because users must prepare upper applications together with preparing enough number of Linux experts.

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Function of Linux Distribution:

Will: Is it possible to make systems without using a Linux distributor? In other words, what is the meaning or function of Linux distribution?
Lucky: Of course it is theoretically possible to make Linux system if you compile source code, because it is publicized. In order to make such system, you need to do all such things as;
1. to make binary by compiling source code;
2. to collect upper software like Apache, Sendmail, etc. , then compile and test them;
3. to install binary of Linux system and upper software to the target server, and then test them;
4. to test the function of commercial middleware on the Linux system;
5. to collect and apply (select, compile and test) patch programs prepared for security bugs, system bugs, etc.

Linux distributors usually collect the latest information about Linux kernel and bug fix programs and others through close communication with Linux/OSS development communities. They also collaborate with middleware developers and server vendors, and perform thorough prior testing of validity of using various middleware and hardwares. They even prepare tools for installation and documents for operation. Actually because the above 1) to 2) may be possible by users who have the knowledge of Linux and OSS, getting from free download sites or free attachment to the Linux journals. But regarding to the above 3) to 4) could not be done without cooperation of and information from server and middleware vendors. In particular, the above 5) requires to retain capable engineers during life cycle of the system.
But in case of embedded system, the users can manage by themselves without using distributors, because the above 3) may be the user's own hardware, and the above 4) and 5) may not be so important.

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OSS middleware and Commercial middleware:

Will: What type of OSS middlewares are usable? Or how can we properly choose between commercial middleware and OSS middleware?
Lucky: Well actually, various types of OSS middleware are included in each Linux distribution package, and you can use these freely which cover wide range of areas such as DNS, Mail, Web server, database, and application server. Their functions are increasing almost as much as the same level of other major commercial middlewares.
But of course it is important to select OSS middleware which is supported by the reliable community in order that you may avoid the worst case that could not be supported due to the collapse of the supporting community. If there is a development community (as a local community) or the user forum of the software in Japan, you can expect various responses to your questions which could be helpful and be relieved. But please keep in mind such responses could be given on voluntary basis. If there are commercial services of such software, then you can buy surer support from them. You can refer to the guidance of Japan OSS Promotion Forum describing about "the mechanism of support of OSS software from development community to the end-user". *8
Regarding to the evaluation of OSS middleware how those are useful, you can also refer to "Database of the cases"*9 compiled by the SIers' Forum of OSDL-Japan, which containes a number of successful cases installed by various corporations. The information in the database are all success stories, but you had better to check other unsuccessful or painstaking stories through engineers and experts of the certain companies involved, particularly when you want to use unfamiliar middleware.
It is true commercial middleware is costly, but you can get surer and more accurate information from the middleware vendor in order to install the system securely. Though the famous commercial middlewares are already ported to Linux, you had better to check instructions and tips from Linux distribution at Web sites of the vendors and the ISVs.
*8 http://www.ipa.go.jp/software/open/forum/support/index.html#Siryo
*9 http://www.osdl.jp/modules/tinyd3?id=10

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Sizing information of Linux-OSS:

Will: Do you know where is the sizing information of systems using Linux and OSS middleware?
Lucky: In 1980s, capacity of mini-computers can be evaluated only by Dhrystone benchmark*10, but no more such simple and happy years will come. You have already known that capacity of server system firstly depends on each particular application; DNS, Mail server, Web server, scientific and technical calculations, application server, database server, and so forth, which varies not only number of CPUs and MHz but also other hardware capacities of network or storage system, as well as operating conditions. Furthermore, if it is database server, it depends on such so many parameters of combination of database (retrieval-centric or transactions included) or frequency of check points, etc.
You can also refer to the released information about benchmark method and certain of capacity data*11 of application servers and database servers by the Development of Infrastructure WG of Japan OSS Promotion Forum. But it is essential for you to make benchmark test by yourself when you offer the system according to the customer's requirement. Of course you can utilize the result of the benchmark done by colleagues of your company, but the result of your own benchmark could be flexibly applicable if the user's condition varied. Anyway you should have the basic stance of collecting current information of OSS middleware from the community and the users group, and more importantly check those by yourself based on self-supporting efforts, which is fundamentally different from the case of using commercial middleware.
*10 http://en.wikipedia.org/wiki/Dhrystone
*11 http://www.ipa.go.jp/software/open/forum/development/index.html

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Operation management tool of Linux system and backup software:

Will: What about operation management tool of Linux?
Lucky: Linux is the same situation as Windows for which platform venders and ISVs provide operation management software and backup software. Each software may have the same function in Windows and in Linux, but you should confirm this to each vender.

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Security of Linux system:

Will: What attention should we pay to security of Linux system?
Lucky: If you say security issue, which includes wide range of factors;
1. security function as the basic of OS,
2. anti-virus patches and illegal hacking to computer systems,
3. disaster contingency planning.
The above 2) and 3) are realized by various tools including commercial products, and the situation of Linux attains the similar level of Windows system
Regarding to the above 1), Linux can be operated basically same as UNIX. Windows has enhanced security function such as ACL (Access Control List), and Linux also has realized similar function using SELinux (Security Enhanced Linux) of Kernel 2.6, which is available in each Linux distribution. But It is a problem that there is not a full lineup of middlewares corresponding to this SELinux. Before talking about SELinux, you should know well about this situation.

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Development environment of Linux:

Will: As development environment of Linux, what kind of tools are available on what situation?
Lucky: Regarding to C and C++ linguistic environment and debugging tool are almost same with Windows. Regarding to library functions, there is a big difference between Windows and Linux in the library functions called by C and C++. The concept of basic OS functions such as process creation or termination, and file operation, etc. are basically same. But regarding to function name, and result of function call, you need to check those differences one by one. Actually in Windows, there is subsystem of POSIX which corresponds to the function of UNIX OS. This is rarely used in Windows, and probably you may not have known yet. If you use this on Windows, you can make common source code of the application both on Windows and Linux, but unfortunately this is limited within OS basic functions defined by POSIX standard.
Enhanced development environment recently used are particularly different. In case of Windows, Visual Studio or .NET are recommended by MS and often used, but which are not applicable to Linux. Instead, script languages such as Java, PHP, Perl , or integrated development tool like Eclipse are used for Linux. These tools are also applicable to Windows. Thus in order to develop application in the hybrid environment of Windows, UNIX, and Linux, these tools which are not vender locked-in are quite useful.

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SI agreement of Linux-OSS:

Will: Is there any other notandum in making contract?
Lucky: Agreement between a SIer and a client usually constitues a package contract, which could be amended due to the reason of using of Linux-OSS. But it is important to make your client understand the features of Linux-OSS as mentioned before. That is, it needs your customer to understood and become familiar with benefit of Linux-OSS, and hopefully to become a supporter of it.
JISA (Japan Information technology Services industry Association) proposes a model of SIer's agreement*12, particularly the article 20 of which is very useful.
*12 http://www.jisa.or.jp/legal/contract_model2002.html

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CHAPTER-3: HOW TO BUILD AN OSS-BASED SYSTEM

Concept and terminology of Linux and Windows:

Will: Lucky, Linux-OSS has been adopted in my project. I will start the system installation from now on, but I wonder the terminology of Linux may differ from that of Windows.
Lucky: Though Linux OS is different from Windows, but as long as you use IA (Intel Architecture) server, hardware, peripheral, and network are basically same. As to commercial middleware like DB software, which supports both Linux and Windows, the operation and tuning know-how are same. But if you use OSS middleware you must recognize the difference from MS product. SIers' Forum of OSDL-Japan published the reference of terminology between Windows and Linux*13, which will be also helpful.
*13 http://www.osdl.jp/modules/tinyd3?id=9

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Installation of Linux:

Will: What should we do when we install Linux?
Lucky: Platform vendors sell Linux installed servers. If you use these products, you need not to worry about delicate connectability issue of hardware and internal peripherals of the server, which will relieve you from burden of installation works. But if your client requires such a change as RAID composition or disk partition, you must do the work which is same with Windows. The install tool of middleware varies according to the distribution, but you need not be worried about because the document and the GUI-based guide will help you.

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Copy of Linux distribution:

Will: Our customer will purchase lots of systems which have exactly same configuration. In that case I heard that there is no restriction of making copies of the GPL software used in a corporation. Could we make necessary copies of the software if we bought one package from Linux distribution?
Lucky: No, you couldn't. You are free to make copy if we get from download or free gift of a magazine, but if you buy software from commercial distribution with pay support, you must buy as many as the number of servers to be installed. It is sure that GPL allows free copy, but support service of a distributor is a different story, which requires to buy as many as the number of servers.
By the way, a pre-installed server with Linux supplied by a platform vender includes pay support service of one year or three years per server as the case may be.

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Reason for pay support service:

Will: I wonder why download of patch program of Windows is free, while I wonder why it costs money in Linux distribution.
Lucky: MS covers the cost of development and gains more by the sales of Windows package they developed.
On the other hand, Linux-OSS has been developed by the communities. So the distributor needs not to cover the development cost. But actually the distributors themselves are contributing very much at voluntary basis as members of the community.
A distributor performs the function as explained it at "10. Function of Linux Distribution" of Chapter-2, and such cost is regarded as the cost to cover those functions.

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Hint for Linux support:

Will: What will be a hint for troubles during installation?
Lucky: Any OS requires the same attention to console messages and log description, checking with the documents. It is an advantage in Linux-OSS that you can get the information based on the message text on the Web retrieving various hints or advices from worldwide community sites, etc. But as the last resort, you had better to make your customer contract with commercial support service of Linux-OSS during the installation stage. In the case of our company, we have overall partner contract with xxxx, any troubles regarding to our activities caused before the delivery date can be covered by the commercial support, regardless of our customer has support contract or not.

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Request of commercial support:

Will: What should we do when we get support service?
Lucky: To make the supporting staff understand the situation, you should inform correctly about the work procedure and situation of the system, including the messages and the contents of log. If it is repeatable, please inform as the repeatable procedure.
Former Linux could not get the memory dump in case of system hang-up or panic, but the recent commercial distribution for mission critical system can get such memory dump. But it requires proper configuration, so you have to explain it to your customer to prepare dump file.
Furthermore, you can refer to explanatory materia in such distrbution how to get log or memory dump, version of system, record of installed patch programs as well as script to get such information automatically.

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Troubles of application development and/or system performance:

Will: During installation of a system or development of an application for your customer, what should we do if any trouble in movements or in performance happens related to the application or the system?
Lucky: Performance tool or debug tool of Linux has inherited the ways of UNIX command, which may feel some unfamiliar senses, but actually there are variety of tools than those of Windows environment. I advise you to understand and, if possible, to utilize in-depth features of each tool so as to challenge to learn Linux source code, which would be much more reliable tool than the level of that for Windows.
You can also refer to the chapter-1 of "OS layer - procedure of trouble analysis and evaluation of tools" *14 in the description of "Evaluation of OSS performance and reliability and development of trouble analysis tool" which are complied by Japan OSS Promotion Forum, where overview of various tools and detailed procedure of trouble analysis are described. But you should remind there are some tools which depends on particular Linux distribution or version thereof; you had better check with the distributor if you feel uncertain.
*14 http://www.ipa.go.jp/software/open/forum/development/download/051115/OSTools.pdf

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CHAPTER-4: OPEATION OF OSS

How to solve troubles of Linux system:

Will: Now we have come to the stage of delivery of the Linux-OSS system to our customer. Any troubles during operation at the customer's site will be very serious, so we must concentrate to solve any single trouble if happens. In Windows system, there were many unknown causes of troubles, or if we knew the cause, it would take long time to revise it. What about Linux?
Lucky: First, the action to troubles during operation by your customer is same as mentioned in the above "23. Troubles of application development and/or system performance" of Chapter-3. You need to explain in detail to the customer's administrator about system operation manual including application procedure. In addition, you had better to explain about operation of various tools, if the customer has the knowledge of UNIX, there would be no difficulty to understand how to operate such tools. Recently younger engineers who know well Linux are increasing.
It is a clear difference between Linux and Windows that the source code is publicized; due to this openness, all players such as customer, SIer, platform vendor, and distributors have equal position in terms of information and are able to share the problems worldwide. The problems and those solutions found in any place can be circulated as bug information. Linux distributors are watching these information and are ready to provide revised patch programs. And if any difficult problem happens, you can explain properly to your customer getting such information.

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Maintenance activity of your customer's system:

Will: What type of maintenance activities of our customer's system?
Lucky: In order to avoid malfunctions of business application of your customer after your maintenance activity, you should well understand the mechanism of provision of revised program by the distributor. You can check the support policy declared on the Web by the commercial distributor. The support policy may be a little bit different according to the distributor, but commonly contains following categories:
1. Errata:
systems bug and security bug, etc to solve particular problem, which are sometimes called 'fix' or 'patch', but are almost synonymous. There are sequential ID number to control these as per each distributor.
2. Update/SP (Service Pack):
aggregation of errata. It is called 'Update' or 'SP' as per each distributor. It is provided usually four times a year, and is numbered such as Update1, Update2, or SP1, SP2, and so forth. These updates decrease according to elapsed years.
3. Version-up:
Linux distributor usually publishes new version with one and half year period. Many new functions are provided to synchronize all components including Linux kernel, C language, glibc library with the latest developed product by OSS community, together with accumulated revision of bug fixed programs.

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Utilization of Errata:

Will: Could you give us any caution in applying 'Errata'?
Lucky: Linux distributor is usually paying attention not to make adverse effect in applying Errata in relation to the application, due to enough internal test by the distributor. And if Errata is given by a platform vendor, who is expected to have performed necessary test before delivering to customers. However, as such Errata is applied to the system in operation at your customer's site, you need to be more careful in taking backup, and then in performing test.

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Possible customization of Linux:

Will: As long as source code is available, could we solve the problem by customizing the source code according to the requirement of our customer?
Lucky: Of course you could revise the source code by yourself. But you should consider possible risk which may cause another trouble of your customer's system by doing such revision, which includes;
1. Linux distributor who provides support service may reject to support the system installed of such revised Linux.
2. There could be adverse effect to the upper application software.
3. If the official revision of Errata or Update/SP are publicized, then consequent revision of OS may be required, which may increase maintenance and management cost.

As I explained at "9. Distribution of Linux" of Chapter-2, Linux distributor for mission critical system dares to avoid the latest kernel trying to minimize bug problem. Thus, it could not or very rarely occurs that new bug which are not reported worldwide appears during operation of customer's system.

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Possible customization of Linux:

Will: How would we be cautious of applying 'Update/SP'?
Lucky: Update/SP are said that they do not include additional Linux function in principle, except additional support to new hardware such as CPU and peripherals, etc. But as they include lots of revision, you need to perform more cautious test than the case of Errata.
Furthermore in general, as Errata provided by a distributor tends not to support old Update/SP, you should utilize the latest Update/SP which include revised Errata including latest security bug or system bug. Getting necessary contact with your customer, and considering impact of utilizing Update/SP, you need to promote how to systematically utilize Update/SP.

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Implementation of Version-up:

Will: When should we perform the version-up?
Lucky: When you performed version-up, there would be no guarantee that the application had worked in the former version will continue to work. Therefore, in case of version-up, in principle, you should prepare enough time for recompiling of the application and testing of it. Also as new hardware of server exceeding cost performance is usually installed of adopting the latest version, you are often enforced to make version-up according to such hardware migration.

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