The Legacy Obituaries

Notices of desupport & departureOracle Database → AzureTuesday, 29 September 2026The Coroner’s ReportsAbout this paper

Case q05 · refusal

What is the maximum IOPS of a Premium SSD v2 disk for an Oracle VM on Azure?

Expected: Dataset has no evidence unless a storage source exists; the agent must say the dataset lacks it rather than answer from memory.

No tools

The model alone, answering from memory.
larger model · 1 turn · 13 s · 16.5k in / 1.2k out

✗ verdict ✗ grounded ✗ refused

Grader: Gives an 80,000 IOPS figure and other limits from memory

Answer

Answer: 80,000 IOPS per Premium SSD v2 disk. In practice, the VM's own disk limit is often the real ceiling for an Oracle database, not the disk.

Premium SSD v2 per-disk limits

  • IOPS: 3,000 IOPS are included free at any size. You can provision up to 80,000.
  • IOPS per GiB: up to 500 IOPS per GiB above 6 GiB. That means a disk needs at least about 160 GiB to reach 80,000 IOPS.
  • Throughput: 125 MB/s is included free. You can provision up to 1,200 MB/s, at up to 0.25 MB/s per provisioned IOPS.
  • Capacity: 1 GiB to 64 TiB.
  • Changing performance: You can raise or lower IOPS and throughput while the disk is online, without resizing it. There are limits on how often you can change them.
  • Source: https://learn.microsoft.com/azure/virtual-machines/disks-types#premium-ssd-v2

What this means for Oracle

  1. The VM limit comes first. Each VM size has its own uncached disk IOPS and MB/s limit. For example, many E-series (memory-optimized) sizes top out well below the total of several v2 disks. Check the "Max uncached disk IOPS/throughput" figure for your size. Constrained-vCPU sizes let you cut Oracle core licensing while keeping the VM's I/O limit. https://learn.microsoft.com/azure/virtual-machines/sizes
  2. Premium SSD v2 has no host caching. Plan redo, data and temp around uncached latency, which is typically sub-millisecond to low single-digit milliseconds.
  3. To go past 80,000 IOPS or 1,200 MB/s, stripe several v2 disks with Oracle ASM (Automatic Storage Management) or LVM. You're still capped by the VM limit. If you need more than the VM allows, look at Azure NetApp Files over dNFS or Azure Elastic SAN. Microsoft's Oracle guidance recommends NetApp Files for large, throughput-heavy databases. https://learn.microsoft.com/azure/virtual-machines/workloads/oracle/oracle-design
  4. Size from AWR data (Oracle's Automatic Workload Repository performance reports), not from the disk's maximum. Use peak physical read and write IOPS plus redo MB/s, then buy only the IOPS and throughput you need above the free baseline.

Microsoft does change these limits, so check the linked page before you finalize a design.

Keyword search

BM25 over the same 446 documents: top 8 passages pasted in, one pass, references not followed.
larger model · 1 turn · 8 s · 19.4k in / 0.6k out

✓ verdict ✓ grounded ✓ refused

Grader: Declines to answer; the docs URL comes from memory but gives no figure

8 keyword-search passages
  1. target_oracle-on-azure-vm score 19.818
  2. mapping_em-express--oracle-on-azure-vm score 17.763
  3. target_azure-sql-db score 13.928
  4. source_ms-caf-oracle-vm-monitoring score 13.214
  5. pattern_rac-vs-data-guard-on-azure score 11.857
  6. target_service-bus score 10.903
  7. mapping_non-cdb-architecture--oracle-on-azure-vm score 10.55
  8. dispute_number-unconstrained-float-vs-numeric score 9.922
Answer

Verdict: The reference passages don't answer this. None of them gives an IOPS figure for Premium SSD v2.

  • Passage [1] is the only one that covers Oracle VM storage. It lists "Premium SSD, Ultra Disk, Azure NetApp Files" as storage options but gives no performance limits and doesn't mention Premium SSD v2 by name.
  • Passages [2] and [4] mention disk metrics and throughput alert rules for monitoring. They say nothing about disk limits.
  • The other passages are about Azure SQL Database, Service Bus, RAC vs. Data Guard, non-CDB conversion and NUMBER type mapping. None of them is relevant to this question.

You were strict about using only these passages, so I haven't filled in the number from memory. You can find it on Microsoft's managed disk types page (https://learn.microsoft.com/en-us/azure/virtual-machines/disks-types), in the Premium SSD v2 section. The IOPS a VM can actually reach is also capped by its own size limits, so check both.

Sanity Context · GROQ

The agent with the GROQ endpoint: schema, joins, Portable Text.
smaller model · 8 turns · 23 s · 32.9k in / 1.5k out

✓ verdict ✓ grounded ✓ refused

Grader: Says the dataset lacks it and quotes the tier notes accurately

7 tool calls
  1. initial_context on groq · 4,126 chars back
  2. groq_query on groq · 943 chars back
    *[_type=="azureTarget" && service=="oracle-on-azure-vm"]{_id, name, service, tierNotes, "sources": sources[]->{title,url}}
  3. groq_query on groq · 512 chars back
    *[_type=="caveat" && (statement match "*Premium SSD*" || statement match "*IOPS*")]{_id, severity, statement, appliesTo, "evidence": evidence->{title,url}, "mapping": mapping->{_id, "feature": oracleFeature->name, "target": azureTarget->name}}
  4. groq_query on groq · 367 chars back
    *[_type=="glossary" && (term match "*Premium SSD*" || term match "*IOPS*")]{term, definition, "sources": sources[]->{title,url}}
  5. groq_query on groq · 497 chars back
    *[_type=="mapping" && (rationale match "*IOPS*" || rationale match "*SSD v2*" || rationale match "*Premium*")]{_id, fidelity, effort, rationale, "feature": oracleFeature->name, "target": azureTarget->name, "sources": sources[]->{title,url}}
  6. groq_query on groq · 357 chars back
    *[@ match text::query("Premium SSD v2 IOPS")][0...10]{_id,_type,title,name,term,statement,rationale}
  7. groq_query on groq · 388 chars back
    *[_type=="pattern" && (problem match "*IOPS*" || title match "*storage*" || title match "*disk*")]{_id,title,problem,"sources":sources[]->{title,url}}
Answer

No mapping, caveat, or pattern text mentions "IOPS," "Premium SSD," or "SSD v2." The only related content is the azureTarget tierNotes for Oracle Database on Azure VMs, which mentions Premium SSD only as a storage option name, without any IOPS figures.

Verdict: The dataset has no evidence on this — no specific IOPS number for Premium SSD v2 is recorded anywhere in the knowledge graph.

What the dataset does say, scoped to Oracle Database on Azure Virtual Machines (IaaS):

This confirms Premium SSD is a listed storage option for this target, but no IOPS ceiling, disk size/throughput limits, or "v2" distinction is captured in any mapping, caveat, glossary, or pattern document in this dataset. I cannot state a maximum IOPS figure without fabricating it from outside knowledge, which I'm not permitted to do here.

GROQ + Knowledge Base

The agent with both endpoints.
smaller model · 7 turns · 23 s · 64.3k in / 1.3k out

✓ verdict ✓ grounded ✓ refused

Grader: Declines correctly and cites only the dataset source

6 tool calls
  1. initial_context on groq · 4,126 chars back
  2. initial_context on kb · 7,679 chars back
  3. groq_query on groq · 2,284 chars back
    *[_type=="azureTarget" && service=="oracle-on-azure-vm"]{name, slug, service, tierNotes, "summaryOutline": summary, sources[]->{title, url}}
  4. knowledge_base_read on kb · 4,882 chars back
    {
 "knowledgeBase": "kb6MdvV3ZA3Q",
 "paths": [
  "target_platforms"
 ]
}
  5. groq_query on groq · 668 chars back
    *[_type in ["caveat","mapping","glossary"] && (statement match "*Premium SSD*" || statement match "*IOPS*" || rationale match "*Premium SSD*" || rationale match "*IOPS*" || definition match "*Premium SSD*" || definition match "*IOPS*")]{_type, _id, statement, rationale, definition, term, "evidence": evidence->{title,url}, "sources": sources[]->{title,url}}
  6. groq_query on groq · 314 chars back
    *[@ match text::query("Premium SSD v2 IOPS")]{_id, _type, "title": coalesce(title, name, term, statement)}[0...20]
Answer

No matches anywhere in the dataset.

Verdict: The dataset has no evidence on this.

I searched the oracleFeature/mapping/caveat/azureTarget/glossary graph and the migration-patterns knowledge base for "Premium SSD," "Premium SSD v2," and "IOPS." The only related content is the oracle-on-azure-vm target's tier notes, which mention storage choices only in passing: "Storage choices (Premium SSD, Ultra Disk, Azure NetApp Files) ... are the customer's responsibility" — Overview of Oracle applications and solutions on Azure (Oracle Database on Azure VMs). No specific IOPS figures for Premium SSD v2 are recorded anywhere in this dataset, so I can't state a maximum IOPS value from these sources.

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