upgrade discussion

7/31/2019 Upgrade Discussion

http://slidepdf.com/reader/full/upgrade-discussion 1/4

System Administration Made Easy D –1

$SSHQGL['8SJUDGH'LVFXVVLRQ

&RQWHQWV

Upgrade Discussion ..............................................................................................D –2

Upgrade Issues ...................................................................................................... D–3

Other Considerations ............................................................................................ D–3



Appendix D: Upgrade Discussion

Upgrade Discussion

Release 4.6A/BD –2

8SJUDGH'LVFXVVLRQ

:KDW

An up grade is an up dating of your R/ 3 System.

:K\

The question of whether to up grade your system to a n ew release depend s on man y

complex factors. Most importan tly, the d ecision to up grade should be based on “business

need.” Some of these factors are ou tlined below:

< Desired functionality in new release

This can be found in the release note for the sp ecific release.

< Problem fixes and resolutions

< The need to be on a supp orted release

5HDVRQV1RWWR8SJUDGH

Some reasons not to u pgrade include the following:

< Cost—the following items could increase the cost of your u pgrade.

You need to:

Upgrade the database and operating system (if required )

Purchase and install additional hardw are (if required )

Test to find p roblems with the upgr ade

Upgrade the SAPgui on the users comp uters

Find the time to do all the above

< Disruption for u sers, especially if there is no functional enhancement for them .

< Diversion of resources (Company resources that could be ap plied to other tasks wou ld

be assigned to up grading the R/ 3 System.)

< Desire to be on the latest release (While desirable for a p ersonal resum e, this reason is

not a valid bu siness reason to upgrade you r system.)

:KHQWR8SJUDGH

In deciding to up grad e your system, ask yourself the following qu estions:

<

Have the reasons for up grading and not up grading been analyzed?< Has the “business need” criteria been met?

< If you installed an y Industr y Solution (IS), are IS pa tches available for the new

release?

If the pa tches are not available, you cannot up grad e.




Upgrade Issues

System Administration Made EasyD –3

8SJUDGH,VVXHV

An up grad e can be more complex than a new implementa tion because:

< There is “real data” on the system that is being upgraded .

If the u pgrad e fails, the company’s operations could be affected an d bu siness could stopThis failure wou ld requ ire you to recover the database (refer to the section on d isaster

recovery).

< The system is unavailable for users d uring a p ortion of the up grade process.

The technical downtime is 6–12 hours. In ad dition, many other tasks are p erformed

around the backup that could increase this “downtime” significantly. System dow ntime

could significantly impact the operations of the business du ring this period.

< Upgrade changes could requ ire changing configuration, testing, training, and

documentation.

< Changes r equire regression testing:

Do business processes function as th ey d id before?

Does custom code need to be changed du e to changes from the upgrade?

2WKHU&RQVLGHUDWLRQV

6RIWZDUH,VVXHV

The following software has to be comp atible with the R/ 3 release you plan to up grad e to:

< Database

< Opera ting system

< Third-party ap plications that compliment the R/ 3 System (for examp le, external tax

packages, job schedulers, system monitors, spool managers, etc.)

+DUGZDUH

< The upgrade requ ires free working space on disks to run.

The amoun t of space required differs with operating system and d atabase.

Some of the space is released after the u pgrade; other space is perman ently used.

< As each release adds fun ctionality, the requ ired d isk space, processing p ower and

mem ory required generally tends to increase.

A system configura tion that was adequ ate for one release may be inadequate for a later

release. This is especially ap parent w hen jum ping release levels; example upgrad ing

from 3.1H to 4.6B. The following table is compiled from SAP notes:




Other Considerations

Release 4.6A/BD –4

SAP Release CPU increase % Memory increase %

3.1H to 4.0B 30 30

4.0B to 4.5B 20 20

4.5B to 4.6A 10 30

3HUIRUPDQFH

Upgrade performan ce is difficult to pred ict. Performance is sensitive to a var iety of

variables, some of wh ich can have significant imp act. Therefore, an up grad e of the test

system should be d one to determ ine timing values for your configuration.

The following a re a few of the factors that affect the performan ce of an u pgrade:

< Database and op erating system

< Hardware

Processor (num ber of processors and speed of each)

Memory (amou nt available)

Drive array

– Performance factor (especially for writes)

– Configuration (minimize or eliminate d rive or chann el contention)

– Other I/ O hard ware (minimize or eliminate data channel contention)

< Data volume for changes to tables that contain data

upgrade discussion

Documents