Installation & Post-Installation

Post-7.2 docs call the main instance the 'primary application server' while older ones say 'central instance.' What actually is an SAP instance, and which service is allowed on only one instance in the whole system?

A SAPinst run fails and you need the cause fast. Among its many XML and log files, which one do you open first, and what's the more verbose companion when it isn't enough?

On Windows, a colleague proposes installing the SAP database or application server on a domain controller to reuse an existing box. Why must you refuse?

A trainer wants a system 'with realistic sample company data' to practice end-to-end business processes. Is that a flag you switch on in a sandbox, or a distinct SAP system?

Your HA design adds a failover cluster but the system still takes a monthly multi-hour patch outage. Which half of high availability have you actually addressed?

First logons after a fresh install or upgrade are painfully slow as each program seems to compile on demand. Which post-install job fixes this, and what's the cost of skipping it?

The install finished and the system runs, but you cannot release a transport. What landscape-level setup is still missing, and where is it done?

A fresh ABAP install ships with clients 000, 001, and 066. Which one do you copy production clients FROM, and which is a security item you should lock down or remove?

After an install or upgrade your PFCG roles misbehave because the authorization check-indicator defaults were never seeded into the customer tables. Which one-time transaction fills them?

A colleague claims the post-install installation check is only reachable as SICK. Is there an equivalent transaction, and do they check different things?

On a current system the docs say to install with SWPM, but the executable is still sapinst. What's going on, and which SWPM version do you pick for ABAP-on-HANA?

SAPinst asks whether to run the 'typical' or 'custom' installation variant. What's the concrete difference in what it will prompt you for?

During a NetWeaver install the database, the application instances, and the frontends all get set up. In what order does SAPinst build them, and why can't the primary application server come up first?

You're installing a brand-new SAP system into an existing landscape and the installer asks for a key you didn't provision. Why can installing another SAP system be blocked entirely if one component is missing from the landscape?

After the technical BASIS install is done, where does the functional team actually configure the system to the customer's business, and what governs the order of those steps?

Your landscape needs one authoritative registry of all systems for transport, monitoring and the like. Which component holds it, and what runtime does that component actually require?

You edited the instance profile on the OS filesystem, but the system still runs with the old values and RZ10 shows them too. What post-install step did you skip?

SLICENSE and USMM both sound like 'licensing.' Which one do you run for the SAP system measurement audit, and what does the other one do instead?

Right after install, users press F1 and get no online help. Which transaction wires the system to the documentation, and what file can silently override it on a single PC?

What is the minimum instance footprint for a working SAP system, and can it all legally sit on one host?

How do you catch a missing OS package or wrong kernel parameter before SAPinst fails halfway through, rather than after?

What single mandatory component distinguishes SAPinst's high-availability variant from a merely distributed install — and what would you lose by omitting it?

You finish a fresh install and the system runs fine. What clock just started, and what specifically must happen before it expires?

SAPinst hits an error and presents Retry / Stop / Continue / View Log. Which do you reach for first, and why doesn't SAPinst just abort?

What must be done on a brand-new SAP system before it's safe to hand over, where omitting any one item is the actual failure?

Must you run the SAPinst GUI on the server being installed? What in SAPinst's design makes the answer matter operationally?

After installation, transaction SICK comes back clean. What did it actually verify — and what does a clean SICK NOT promise about your system?

You need to add a new language to a system that also has support packages waiting. What's the ordering trap, and which two languages need no import at all?

A customer can give you a clean user count but cannot reliably estimate document volumes yet. Which Quick Sizer approach fits, and what's the cost of forcing the other?

A SAPinst run dies partway through the processing phase. Why is re-launching and re-entering all your parameters the wrong move, and what makes a clean resume possible?

A landscape plan puts DEV on Windows and PRD on UNIX to save hardware. Why is this not allowed, and what landscape difference IS supported?

Why does a clustered or standby SAP system need more than one license file, and where do you read off the value the key is bound to?

You need to de-install an old system and clone another. Do you go hunting for separate tools, or is SAPinst enough?

You've just imported a permanent license in SLICENSE during business hours. Do you need to plan downtime for it to take effect?

A team proposes MCOD to cut hardware cost by running several SAP systems together. What does MCOD actually buy you, and what's the catch that often kills the idea?

Before installing, where must you confirm that your exact OS-version + DB-version combination is supported, and what happens if you skip this check?

A stakeholder asks to roll out a 'supported' SAP language. Why can 'available' still mean an incompletely translated UI, and which languages avoid that gap entirely?

A junior admin insists each default user still ships with its own well-known fixed password from a table. What changed as of NetWeaver 7.0, and why doesn't that make the system safer by default?