Linux Administration, Port Architecture & Instance Numbering
Master the Linux filesystem layout, core management CLI tools (HDB start/stop/info, sapcontrol, hdbsql), instance numbering formula (00-99), and complete network port matrix for SystemDB and tenant databases.
IntermediateLinux & OS~18 min studyHANA 2.0 (All SPS)
Core Learning Objectives
- 1.Decode the SAP HANA port calculation formula based on 2-digit Instance Number (NR).
- 2.Understand the filesystem hierarchy (/hana/shared, /hana/data, /hana/log, /usr/sap).
- 3.Execute database lifecycle commands safely from the Linux command line.
- 4.Use OS diagnostics (ss, lsof, df, free, top, journalctl) to triage service blockages.
Prerequisites:hana-architecture-services-overview
Definition & Architectural Rationale
Technical Definition:
SAP HANA uses a strictly standardized port numbering scheme derived mathematically from the two-digit system instance number (00 to 99), ensuring that multiple SAP instances can coexist on a single server without port collisions.
Why this component exists:
In enterprise datacenters with firewalls, load balancers, and multi-tier SAP application architectures, understanding exact network ports and listening interfaces is essential for establishing client connectivity, configuring HSR, and diagnosing firewalled connections.
Internal Working & Mechanics
1. The Port Calculation Formula:
Every port in SAP HANA follows the pattern: 3<NR><ServicePort> or 5<NR><ServicePort>.
Where <NR> is the two-digit instance number (e.g. 00, 01, 10, 42).
For Instance 00:
- 30001: hdbnameserver internal communication port
- 30002: hdbpreprocessor port
- 30003: hdbindexserver internal communication port
- 30010: hdbcompileserver port
- 30013: SystemDB SQL client listener port
- 30015: First Tenant Database SQL client listener port (Index Server)
- 30040+: Dynamic SQL ports assigned to additional tenant databases
- 50013: sapstartsrv HTTP SOAP port
- 50014: sapstartsrv HTTPS secure port
- 1128 / 1129: SAP Host Agent HTTP / HTTPS (host-level, instance independent)
For Instance 02 (NR = 02):
- SystemDB SQL port: 30213
- Tenant SQL port: 30215
- sapstartsrv HTTP: 50213
2. Filesystem Structure:
- /hana/shared/<SID>: Binaries (exe/), instance profile (SYS/profile), HDBLCM scripts, trace history.
- /hana/data/<SID>/mnt00001/: Persistent database blocks; subdivided by service (hdb00001 = nameserver, hdb00002 = first tenant indexserver).
- /hana/log/<SID>/mnt00001/: Active redo log segments (typically 512 MB to 1 GB each).
- /usr/sap/<SID>/HDB<NR>: Local instance directory containing symlinks to executables and instance trace directory.
Architecture Flow Diagram
Mermaid DiagramLinux Administration, Port Architecture & Instance Numbering
Architectural Flow: Port numbers are derived directly from the instance number (NR=00). SystemDB listens on 30013, default tenant on 30015, and sapstartsrv on 50013.
Linux Terminal Diagnostics & Operations
Core SAP HANA Instance Lifecycle Commands
user: <sid>adm
Provides foundational administration of the HANA instance at the operating system level.
hdbadm@host $ HDB version
HDB info
HDB start
HDB stop
Terminal Standard Output (stdout):
HDB version: version: 2.00.070.00.1679941421 branch: fa/hana2sp07 compile time: 2023-03-27 19:45:00 ... HDB stop: Stopping 5 processes... hdbindexserver stopped. hdbcompileserver stopped. hdbpreprocessor stopped. hdbnameserver stopped. hdbdaemon stopped.
Output Analysis: HDB version prints the revision and build timestamp. HDB stop gracefully signals child services to complete active transactions and flush redo logs.
Inspect Active HANA Listening Sockets via ss
user: root
Verifies whether SystemDB (3<NR>13) and Tenant (3<NR>15) SQL listener ports are successfully bound to listening sockets.
root@host # ss -tulnp | grep -E "3[0-9]{2}(13|15)"
Terminal Standard Output (stdout):
tcp LISTEN 0 128 0.0.0.0:30013 0.0.0.0:* users:(("hdbnameserver",pid=4812,fd=32))
tcp LISTEN 0 128 0.0.0.0:30015 0.0.0.0:* users:(("hdbindexserver",pid=4890,fd=45))Output Analysis: Both ports are in LISTEN state on 0.0.0.0 (all interfaces). If a port is missing, the corresponding service failed to start or is still replaying logs.
Inspect Filesystem Mounts and Free Space
user: any
Ensures data and log persistence volumes have adequate free space to prevent disk-full stalls.
$ df -hT /hana/data /hana/log /hana/shared /usr/sap
Terminal Standard Output (stdout):
Filesystem Type Size Used Avail Use% Mounted on /dev/mapper/vg_data-lv_data xfs 1.5T 620G 880G 42% /hana/data /dev/mapper/vg_log-lv_log xfs 512G 85G 427G 17% /hana/log /dev/mapper/vg_shared-lv_shared xfs 500G 110G 390G 22% /hana/shared /dev/mapper/vg_root-lv_usrsap xfs 80G 24G 56G 30% /usr/sap
Output Analysis: Persistence mounts are formatted with XFS filesystem with healthy utilization across all volumes.
Troubleshooting & Root Cause Analysis
Production Best Practices & Operational Risks
Mandatory Best Practices
- Always execute database maintenance commands as the <sid>adm user, never as root!
- Never edit instance profile files under /usr/sap/<SID>/SYS/profile manually while services are running; use SAP tooling or parameter configuration files.