OS & Application Server Layout

How does /usr/sap/trans fundamentally differ from every other SAP directory, and what parameter pins it down?

You see traffic on port 8042 hitting an SAP host. Which ICM service and which instance does that imply, and via what parameter is it set?

Where should the shared transport area physically live, and what is the trade-off that drives the choice?

You're documenting startup. On Windows, what handles launching instance processes, and what Linux process is conspicuously absent?

Under which account do SAP processes actually run on Windows vs Linux — and why is that a frequent wrong assumption?

A work process short-dumped on startup. Under the instance directory, do you open the dev traces in log/ or in work/ — and what does the other one hold?

Why should you avoid instance number 89 for SAP on Windows specifically?

Among dispatcher, gateway, and message server ports, which one is NOT keyed to the instance number — and how is it keyed instead?

On Windows there are two SAP shares, sapmnt and saploc. Which points to the global host and which to the local host — and why does getting it backwards matter?

On Linux/UNIX, if you kill the sapstart process after the instance is up, what happens to the running work processes — and why?

Coming from an older NetWeaver landscape, which platforms did S/4HANA 1809 drop support for?

An instance is fully down — no dispatcher, no work processes. Which kernel component can you still reach to start it and read its logs, and via what tool?

On Linux/UNIX, who owns the SAP system directories, and which separate user is tied to the SAP Host Agent?

On a Windows app server, which of the two SAP users must be a Local Administrator — and which must you keep OUT of that group?

A released transport produces a cofile and a datafile. Which one carries the changed objects, and which the phase/status metadata?

Why can SAP port numbers collide with non-SAP applications on the same server, and what does that change about how you assign instance numbers?

You need a file visible to ALL application servers vs one that stays local to a single app server — which top node, /sapmnt/SID or /usr/sap/SID?

After a kernel/release upgrade, what keeps each instance's LOCAL kernel copy in sync with central — and why isn't a manual full recopy needed?

On S/4HANA you find exe/nuc empty and exe/uc populated. Is that a broken install, and where do the actual binaries live?

Which Windows Server versions and editions does S/4HANA 2022 support?

Under /sapmnt/SID, which subdir holds the kernel executables and which holds shared runtime data like background job logs?

SAP installs two OS groups, sapsys and sapinst. Which is the everyday owner group and which exists only for installs?

When does a Windows SAP install REQUIRE a domain installation instead of a local one?

If you're opening firewall rules for monitoring, which SAP management ports are fixed per-host and which vary per instance?

On a HANA-based system, why is icmbnd typically the ONLY SAP kernel program running with root privilege?

If you edited a profile under /usr/sap/SID/SYS, where is the change really landing — and why?

In the transport area, where do import requests queue up, and what is the EPS directory used for instead?

Why does the SAP Host Agent directory carry no SID, and what does that tell you about how many you install per host?

Which operating systems can the S/4HANA application server run on — and what's the trap in 'it's Linux'?

On Windows, how does an instance learn its global vs local host, and which two Linux conveniences are simply missing?

Your S/4HANA runs on AWS as IaaS. SAP treats that the same as on-premise, so why should you as the admin treat it differently?

An admin migrating an old NetWeaver 7.52 system running on IBM i to the ABAP Platform is surprised the OS is no longer supported. Which platforms did SAP drop, and which remain?

An admin assumes an S/4HANA landscape is IPv4-only when planning network addressing. What does SAP actually support today, and how is the SAP HANA network split?