Oracle Dba Exadata Engineered Systems

Oracle DBA - Exadata / Engineered Systems

Health, storage-cell visibility, IORM/Smart-Scan/flash diagnostics, patch readiness, and the plan-only Tier-3 runbooks for Oracle Exadata Database Machine (19c and 23ai; EE; single-instance and Data Guard; on-prem). Two mechanisms by design:

• In-DB work (offload stats, ASM headroom, DBRM plans, CELL_FLASH_CACHE attributes) runs through the SQLcl MCP saved connection dba_ai_conn → sql/*.sql ("sqlcl-mcp").
• Host work (exachk/AHF, cellcli/dcli, patchmgr) cannot go through SQLcl MCP (restrict level 4) → .sh/.ps1 ("script", to later front a guarded oracle-dba-ops MCP).

Everything self-executing is T1 (observe) or T2 (reversible, dry-run-default). Every cell/switch/compute patch apply, storage-cell mutation, cell IORMPLAN config, cell flash-cache tuning, and rack expansion is T3 and lives only in references/runbooks.md — it prints commands for a human and never self-executes.

Scope & risk map

Preconditions

• SQLcl MCP connection dba_ai_conn is reachable and wallet-backed. All in-DB prechecks, postchecks, idempotency probes, and sql/*.sql run through it via connect_db / Connect-Db. Never SYS/SYSTEM — except inside a T3 runbook that explicitly states AS SYSDBA / AS SYSASM (e.g. ASM ALTER DISKGROUP), supplied interactively by the operator.
• Secrets resolve from the Oracle Wallet / external password store. No plaintext anywhere. Host tools (patchmgr, cellcli, dcli, exadcli, ahfctl, asmcmd, srvctl) use OS / key-based SSH set up out of band — never a password on argv. The shared helpers reject credential-looking arguments with ERR_SECRET (8).
• Helpers are sourced from _common (scripts/lib.sh / lib.ps1): connect_db, log_event, emit_metric, require_dry_run, guard_blocked_dry_run, require_approval_token, precheck, postcheck, print_banner. Not reinvented.
• Host reachability: cell/IORM/patch scripts need a node from which cellcli/dcli/ patchmgr can reach the cells/switches/db-nodes via SSH keys, with the group files (cell_group, ibswitch_group, dbs_group) present. Off-cluster, the read-only scripts log noop and fall back to the in-DB summary.
• Logging: structured key=value lines to the canonical paths /var/log/oracle-dba/exadata/exadata.log (Linux) / C:/ProgramData/oracle-dba/logs/exadata/exadata.log (Windows); skill segment exadata.
• T2 dry-run default: every T2 script previews and changes nothing unless given --execute. patch_precheck additionally REFUSES to apply patches even with --execute (it only runs patchmgr -precheck); the apply is T3.

Procedures

Scripts ship as behaviour-equivalent .sh (Linux) / .ps1 (Windows) pairs. T2 scripts default to --dry-run; pass --execute to act. See each script's --help.

Exadata health check (exachk / AHF) — T1

• Trigger: weekly best-practice health check; before/after any cell/patch/expansion work.
• Precheck: dba_ai_conn reachable (for the in-DB summary half).
• Action: scripts/run_exachk.sh --silent / .ps1 -Silent ("script") + sql/exadata_health_summary.sql ("sqlcl-mcp"). --skip-indb for host-only.
• Postcheck: n/a — emits metrics (cell_count, asm headroom, rebalance) + report path; a failing best practice is a finding, not a failure.
• Rollback note: none — read-only.

Storage-cell status — T1

• Trigger: daily; investigating a non-NORMAL disk or a critical cell alert.
• Precheck: none (read-only); auto-detects the cell group / runner.
• Action: scripts/cell_status.sh [--detail] / .ps1 [-Detail] ("script", cellcli/dcli LIST only).
• Postcheck: n/a — surfaces unexamined critical alerts + non-NORMAL griddisks as findings.
• Rollback note: none — read-only. Cell mutation is T3 #cell-management.

IORM visibility — T1

• Trigger: confirm the active IORM/DBRM picture across cells + DB.
• Precheck: dba_ai_conn reachable (in-DB half).
• Action: scripts/iorm_status.sh / .ps1 ("script", cell LIST IORMPLAN) + sql/iorm_status.sql ("sqlcl-mcp").
• Postcheck: n/a — read-only.
• Rollback note: none. Cell IORMPLAN config is T3 #iorm-config; activating an existing DBRM plan is the T2 below.

Smart Scan / flash & expansion diagnostics — T1

• Trigger: "why am I (not) getting Smart Scan/flash benefit?" / pre-expansion fact-finding.
• Precheck: dba_ai_conn reachable.
• Action: sql/smartscan_diagnostics.sql / sql/expansion_readiness.sql ("sqlcl-mcp").
• Postcheck: n/a — read-only; emits offload/headroom KEYVAL metrics.
• Rollback note: none — read-only.

Exadata patch readiness PRECHECK — T2

• Trigger: before a quarterly image/RU; validate a component CAN be patched.
• Precheck: component valid; on --execute, patchmgr present + patch dir / target list exist.
• Action: scripts/patch_precheck.sh --component cells|switch|compute [--patch-dir DIR] [--target-list FILE] --execute / .ps1 ("script"). Dry-run prints the exact patchmgr -precheck command; --execute runs the precheck (still non-destructive).
• Postcheck: precheck output reports READY (no FAILED/ERROR).
• Rollback note: none — precheck never applies. The APPLY is T3 #exadata-patching.

In-DB DBRM plan activation — T2

• Trigger: switch the active in-DB resource plan (the in-DB half of IORM on Exadata).
• Precheck: dba_ai_conn reachable; the requested plan must already EXIST (else blocked).
• Action: scripts/dbrm_plan_apply.sh --plan NAME --execute / .ps1 -Plan NAME --execute ("script") + sql/dbrm_plan_apply.sql ("sqlcl-mcp"). Dry-run reports the current plan only.
• Postcheck: requested plan is the active top plan (or already-active no-op).
• Rollback note: reversible — re-activate the previous plan (printed). Creating/altering a plan DEFINITION is T3 #iorm-config.

Smart Flash Cache segment hint — T2

• Trigger: pin a hot small table/index in flash (KEEP) or release it (DEFAULT/NONE).
• Precheck: dba_ai_conn reachable; owner/table valid; mode in KEEP|DEFAULT|NONE.
• Action: scripts/flashcache_hint.sh --owner O --table T --mode KEEP --execute / .ps1 -Owner O -Table T -Mode KEEP --execute ("script") + sql/flashcache_hint_apply.sql ("sqlcl-mcp").
• Postcheck: CELL_FLASH_CACHE attribute equals the requested mode.
• Rollback note: reversible — set --mode DEFAULT. Cell-side flash sizing/mode is T3 #flashcache-tuning.

Tier-3 runbooks

All destructive Exadata work is Tier 3 and lives in references/runbooks.md: #exadata-patching (cell/switch/compute apply + GI/RDBMS/datapatch), #cell-management (griddisk/celldisk/disk/firmware), #iorm-config (cell IORMPLAN + DBRM plan DDL), #flashcache-tuning (cell flash cache CREATE/ALTER/DROP), and #expansion (add cells/nodes + ASM rebalance).

These runbooks PRINT exact cellcli/patchmgr/ASM/SQL commands for a human operator and NEVER self-execute. They are gated by require_approval_token / Require-ApprovalToken: an automated agent's only sanctioned action is to print the relevant section and stop with ERR_APPROVAL (6) until a human supplies a real change ticket/token (--token <TICKET> or ODB_APPROVAL_TOKEN; placeholders are rejected). The T2 scripts deliberately refuse the destructive paths (patch_precheck never applies; the wrappers never define plans or touch cell hardware) and point to the runbook instead. SYSDBA / SYSASM is a T3-only, interactively-supplied exception. When in doubt, runbook.

See references/version-notes.md for 19c-vs-23ai (and Exadata-image) behavioural deltas, and cron/crontab.d / cron/task-scheduler.xml for the schedulable T1/T2 jobs.