Database and transactional storage

Design the storage path around every committed transaction

Database performance depends on more than headline throughput. Predictable write latency, correct flush behaviour, stable storage, recovery points and a tested failover path determine whether a transactional service remains both fast and trustworthy.

A commit crosses the complete I/O path
DATABASE TRANSACTION
LOG / WALsmall, latency-sensitive writes
DATA FILESmixed reads, writes and checkpoints
HOST → FABRIC → STORAGE
 
ACKNOWLEDGE ONLY AFTER THE REQUIRED DURABILITY BOUNDARY
Latency is an end-to-end propertyHost, queueing, network, controller, media and protection policy all contribute.
Averages conceal disruptive pausesTail latency during checkpoints or rebuilds can matter more than a peak benchmark.
Durability depends on correct acknowledgementA completed write must have crossed the boundary promised to the database.
Availability is not historical recoveryFailover can continue serving a damaged database unless usable recovery points also exist.
Database I/O

One database produces several storage workloads

Sizing only for capacity or aggregate bandwidth overlooks the operations that govern transaction time and recovery behaviour.

TRANSACTION LOG

Frequent durability points

Write-ahead and redo logs commonly issue small sequential writes whose completion can sit directly in the transaction path.

DATA AND INDEXES

Mixed, concurrent access

Reads, page updates, background flushing and index maintenance compete for queues and cache resources.

TEMPORARY WORK

Bursts from sorts and joins

Temporary data, spills and maintenance tasks can create short periods of high throughput and queue depth.

CHECKPOINTS

Background work becomes visible

Dirty-page flushing, snapshots, rebuilds or backup activity can change latency even when the application workload has not changed.

Important: a database benchmark should reproduce transaction mix, concurrency, working set, protection policy and failure-state operation. A short sequential test does not represent this behaviour.

Design priorities

Protect correctness before optimising speed

01

Stable writes

Flushes, write ordering and protected caches must preserve the durability model expected by the database and operating system.

02

Predictable latency

Review normal operation, peak periods, degraded mode, rebuilds, snapshots and backup windows—not only the fastest result.

03

Path resilience

Multipathing, redundant network links and correctly configured host time-outs reduce the chance that one path event stops the service.

04

Recoverable history

Application-consistent backup, retained recovery points and restore testing remain necessary even when storage is highly available.

Workload profiles

Different database services stress different parts of the system

The application owner and storage designer should describe the workload before selecting a transport or platform.

PROFILE 1

Online transaction processing

Latency-led

  • Many concurrent, relatively small operations
  • Commit latency and tail latency can affect user response time
  • Logs and data may need different service levels
PROFILE 2

Analytics and reporting

Throughput-led

  • Large scans and parallel reads can consume bandwidth
  • Temporary work areas may create bursty writes
  • Capacity growth and data movement matter alongside latency
PROFILE 3

Consolidated database VMs

Mixed demand

  • Several databases share host, fabric and storage queues
  • Noisy neighbours can make latency less predictable
  • Virtualisation HA and storage HA solve different failure layers
PROFILE 4

Distributed and scale-out data services

Failure-domain led

  • The application and storage may both replicate data
  • Placement policy changes capacity and write amplification
  • Quorum, recovery traffic and degraded mode require testing
Data access model

Block, file and object storage serve different database roles

B

Block storage

The host receives a volume and the operating system controls its filesystem. This is the conventional choice for many transactional databases and clustered database designs.

Common roles

  • Data and index volumes
  • Transaction or redo logs
  • Database volumes inside virtual machines
F

File storage

The database accesses files through a shared filesystem protocol. Suitability depends on the database vendor, operating system, locking semantics and the supported deployment design.

Common roles

  • Supported database shares
  • Exports, imports and shared content
  • Backup repositories
O

Object storage

Applications address objects through an API rather than a mounted database volume. It is normally a complementary tier, not a direct replacement for transactional block I/O.

Common roles

  • Database backup and archive
  • Data-lake and analytics content
  • Application objects and unstructured data

Do not select by protocol name alone: confirm that the database, operating system, clustering method and backup tooling support the complete configuration.

Block access choices

Choose the fabric by operational fit and latency objective

Every shared-storage protocol can be implemented well or poorly. The complete path and supported host configuration determine the result.

Access methodInfrastructurePerformance characterOperational advantagePoints to validate
Local NVMePCIe-attached media in the database hostVery low local latencyShort I/O path and no storage fabricHost failure boundaries, shared access, migration and external recovery
NVMe over RDMARoCE/RoCEv2 or InfiniBand fabricLow overhead and low latency potentialExtends NVMe block access across a fabricQualified adapters, switches, fabric configuration, multipathing and operations skills
NVMe over TCPStandard routed Ethernet/IP networkEfficient NVMe access over TCPFamiliar IP operations and broad network reachCPU load, congestion, path design, host support and workload latency
Fibre ChannelDedicated FC fabric with HBAs and switchesMature and predictable when correctly designedEstablished SAN isolation, zoning and multipath practicesSpecialist infrastructure, port capacity, interoperability and lifecycle cost
iSCSIEthernet/IP network and standard SCSI initiatorsMature general-purpose block accessBroad compatibility and familiar administrationNetwork separation, queueing, multipathing, time-outs and peak workload behaviour
File protocolShared file service over EthernetDepends strongly on client and workloadFile-level administration and shared namespacesExplicit database support, locking, cache semantics and application design

NVMe over TCP and NVMe over RDMA use the NVMe over Fabrics architecture but make different infrastructure trade-offs. RDMA can reduce transport overhead; TCP usually fits more easily into established IP operations. Measure with the intended database workload.

Service-level separation

Separate I/O classes logically—even when they share hardware

Logs, data, temporary work and backups do not always need separate storage systems. They do need identifiable policies, capacity limits and monitoring so that one activity does not unexpectedly consume the service level required by another.

  • Protect the transaction-log path from uncontrolled queueing.
  • Allow space for checkpoints, maintenance and rebuild traffic.
  • Keep backup traffic from dominating the production path.
  • Monitor latency percentiles and saturation, not only bandwidth.

Four I/O lanes, four operating questions

Isolation may use volumes, namespaces, pools, quality-of-service controls or separate paths according to the platform.

LOG / WAL
How quickly and safely is a durable write acknowledged?
DATA
Can foreground reads coexist with checkpoints?
TEMP
What happens during a spill or maintenance burst?
BACKUP
Can protection run without destabilising production?
Reference architectures

Match the platform to the database failure boundary

These euroNAS examples illustrate different implementation models. They are not a substitute for validating the database vendor’s supported configuration.

ARCHITECTURE 1

Dedicated high-performance storage

Standalone

Database host or cluster
euroNAS Premium

A focused storage system for database environments whose availability design is handled at the host, application or recovery layer. It can also be deployed as a Virtual Storage Appliance where that architecture is appropriate.

  • Block access using the protocol selected for the hosts
  • Snapshots and scheduled replication for storage recovery points
  • No automatic storage-controller failover within one standalone server

Explore euroNAS Premium →

ARCHITECTURE 2

Two-node database storage availability

Automatic failover

Multipathed database hosts
euroNAS HA Cluster

A two-node storage design with automatic service failover, implemented as a synchronous Mirror between servers or with dual controllers and shared storage.

  • Designed for local storage-service continuity
  • Multipathing protects host access across available paths
  • Snapshots and scheduled replication remain separate recovery controls

Explore HA Cluster →

ARCHITECTURE 3

Distributed scale-out database storage

No fixed two-node limit

Database clients or VM cluster
eEKAS Ceph block storage

Distributed block storage across multiple nodes can suit capacity growth, infrastructure fault tolerance and larger consolidated environments.

  • Protection across defined Ceph failure domains
  • Scale capacity and performance by adding qualified nodes
  • Validate latency, recovery traffic and application-level replication together

Explore eEKAS →

ARCHITECTURE 4

Databases as protected virtual machines

Virtualisation platform

Database VMs
eEVOS compute, storage and recovery

eEVOS runs database workloads as virtual machines and can use mirrored, shared or Ceph storage according to the cluster design. External shared storage can also be connected.

  • Virtual-machine HA and live migration
  • Internal or external storage options
  • Integrated Backup & Disaster Recovery, including Instant Backup & Recovery

Explore eEVOS →

Availability and recovery

Protect the service at more than one layer

Database clustering, storage failover, replication and backup are complementary controls with different recovery outcomes.

PATH RESILIENCE

Keep access available

Redundant links and multipathing protect against an adapter, cable, switch port or storage path failure.

SERVICE FAILOVER

Continue after a node fails

Application clustering, virtualisation HA or storage failover can restart or continue the service at different layers.

REPLICATION

Cross a larger boundary

Synchronous and asynchronous copies address different distance, data-loss and performance objectives.

BACKUP & DR

Return to a usable state

Retained recovery points and tested procedures protect against deletion, corruption, security incidents and site loss.

Application consistency matters: coordinate database flushes, snapshots, replication and backup with the database’s supported recovery model. A storage-consistent copy is not automatically an application-consistent recovery point.

Implementation examples

euroNAS platforms address different database designs

Selection should follow workload, host support, failure boundaries and operational skills—not a single protocol or feature.

PlatformPrimary database roleStorage modelAvailability contributionDesign consideration
euroNAS PremiumDedicated or virtual storage appliance for a focused database environmentStandalone block and file storageHost multipathing where configured, plus storage recovery pointsApplication or external recovery design must cover complete server loss
euroNAS HA ClusterShared database storage requiring automatic local storage failoverTwo-node synchronous Mirror or dual-controller shared storageAutomatic storage-service failover and multipathed host accessSize performance for normal and failover operation; retain separate backups
eEKASDistributed block storage for larger consolidated or scale-out environmentsCeph across multiple storage nodes and failure domainsDistributed redundancy, recovery and scale without a fixed two-node boundaryTest database latency together with Ceph protection and degraded-mode recovery
eEVOSDatabase virtual machines on an integrated virtualisation platformMirrored, external shared or Ceph storage according to deploymentVM HA, live migration and storage architecture chosen for the clusterCoordinate database-native protection with integrated VM Backup & Disaster Recovery
FOCUSED STORAGE

euroNAS Premium

Standalone storage for database hosts or virtualised environments.

Premium details →

LOCAL STORAGE HA

HA Cluster

Automatic two-node storage failover with a synchronous Mirror or shared-storage design, plus scheduled asynchronous replication for additional recovery protection.

HA Cluster details →

DISTRIBUTED STORAGE

eEKAS

Ceph block storage across nodes and defined failure domains.

eEKAS details →

DATABASE VMS

eEVOS

Virtualisation, storage and VM Backup & Disaster Recovery in one platform.

eEVOS details →

Before choosing the architecture

Ask questions the benchmark cannot answer

01 · TRANSACTION PROFILE

What are the read/write mix, concurrency, block sizes, log behaviour and latency objectives?

02 · FAILURE STATE

What performance remains acceptable during path loss, failover, rebuild or distributed recovery?

03 · DURABILITY

Which flush, cache-protection, write-ordering and stable-media guarantees does the database require?

04 · HOST SUPPORT

Which operating systems, multipath drivers, hypervisors and database cluster modes are qualified?

05 · RECOVERY OBJECTIVE

Which RPO and RTO apply to deletion, corruption, node loss and a complete site outage?

06 · GROWTH

Will capacity, transaction rate, node count or retention grow—and which component reaches its limit first?

Primary references

Independent technical guidance

Database and transport requirements evolve. Validate the final design against the current database, operating-system and storage documentation.

Microsoft: SQL Server I/O requirements

Write ordering, stable media, dependent-write consistency and torn-I/O considerations.

Open Microsoft guidance →

MySQL: InnoDB redo log

The role of redo logging in crash recovery and the relationship between log capacity and background flushing.

Open MySQL documentation →

Architecture discussion

Bring the database workload—not only the capacity figure

We can review transaction characteristics, latency objectives, host compatibility, availability, recovery and growth for a business database or virtualisation design.

Discuss your database architecture

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