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Stanislav Hubacek ef3c2f75b1 18.6.2026

2026-06-18 16:25:33 +02:00

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💾 Storage infrastructure

Storage types

Type	Description	Latency	Use case
DAS (Direct Attached)	Disks directly in server	<0.1 ms	OS, cache, local data
SAN (Storage Area Network)	Block devices over network	<1 ms	Databases, VM datastores
NAS (Network Attached Storage)	File access (NFS, SMB)	1-3 ms	Shared files, home dirs
Object storage	REST API, flat namespace	10-100 ms	Backups, media, big data

Protocols

Protocol	Type	Speed	Note
Fibre Channel	SAN	8/16/32/64 Gbps	Low latency, dedicated network
iSCSI	SAN (IP)	1/10/25 GbE	Cheaper, over ethernet
NVMe-oF	SAN (NVMe)	25/50/100 GbE	Lowest latency, emerging
NFS	NAS	1/10/25 GbE	Universal, simple
SMB/CIFS	NAS	1/10/25 GbE	Windows native
S3 API	Object	—	Standard for object storage

RAID

RAID	Min. disks	Capacity	Protection	Read speed	Write speed	Use case
0	2	100 %	None	N × (striping)	N ×	Temp data, cache (risky)
1	2	50 %	1 disk	N × (mirror)	1 ×	OS disk, critical data
5	3	67-94 %	1 disk	N-1 ×	N-1 × (parity write penalty)	Universal file/VM storage
6	4	50-88 %	2 disks	N-2 ×	N-2 × (double parity)	Large capacities, important data
10	4	50 %	1/mirror	N ×	N/2 ×	Databases, VM, high-performance
50	6	67-94 %	1/stripe	N-1 ×	N-1 ×	Large capacity + performance
60	8	50-88 %	2/stripe	N-2 ×	N-2 ×	Enterprise

Stripe size

Small stripe (16-64 KB) — better IOPS, worse throughput (databases, OLTP)
Large stripe (128-1024 KB) — better throughput, worse IOPS (video, media, backup)
Write hole on RAID 5/6: metadata inconsistency during power loss while writing parity (prevention: non-volatile cache, battery-backed RAID controller)

Software-Defined Storage (SDS)

Tool	Type	Use case
Ceph	Object/Block/File (RADOS)	Universal SDS, OpenStack, Kubernetes
MinIO	Object (S3 API)	High-performance S3, AI/ML data lake
GlusterFS	Distributed File	Shared filesystem, POSIX
Longhorn	Block (Kubernetes)	K8s PVC, microservices
Linstor	Block (DRBD + LVM)	Linux SDS, Kubernetes
VMware vSAN	Block (HCI)	VMware ecosystem
StarWind	Block (HCI)	Hyper-V / VMware

Ceph

Architecture:

RADOS (Reliable Autonomic Distributed Object Store)
    ├── Monitors (MON) — cluster map, quorum (3/5)
    ├── Managers (MGR) — dashboard, balancer, orchestrator
    ├── OSDs (Object Storage Daemons) — data + replication
    └── MDS (Metadata Server) — CephFS only

CRUSH map (Controlled Replication Under Scalable Hashing):

Algorithm for calculating data placement (no central index)
Layers: Root → Datacenter → Rack → Host → OSD
Failure domain: replication across racks / hosts
ceph osd crush rule create-replicated replicated_rule default host

Access interfaces:

Interface	Type	Use case
RBD (RADOS Block Device)	Block	VM images, Kubernetes PVC (csi-rbd)
RGW (RADOS Gateway)	Object (S3/Swift API)	S3-compatible storage, backup
CephFS	File (POSIX)	Shared filesystem, home dirs
NFS-Ganesha	File (NFS)	NFS export over CephFS

Erasure coding:

K+M (data + parity chunks), e.g. 8+3 (8 data, 3 parity)
More space-efficient than 3× replication (1.375× vs 3×)
Higher CPU overhead, lower IOPS
Recommended for cold data (RGW) instead of replication

Enterprise storage vendors

Hitachi VSP (Virtual Storage Platform)

Model	Architecture	Max capacity	IOPS / Latency	Protocols	Use case
VSP 5200/5600	Active-active, scale-up/out, 2–12 controllers	69.3 PB raw, 287 PBe	33M IOPS, 39 µs	FC-NVMe 32Gb, FC 16/32Gb, FICON 16Gb, iSCSI 10Gb	Mission-critical, mainframe, enterprise consolidation
VSP E590/E790/E1090	Symmetric active-active, up to 65 nodes/130 controllers	10.62 PB raw (E1090)	8.4M IOPS, <41 µs	FC 32Gb, iSCSI 25Gb, FC-NVMe 32Gb	Midrange enterprise, hybrid workloads

Key features: SVOS common across entire portfolio, AI-driven data reduction 4:1 guarantee, Global-Active Device metro clustering, 8 nines availability (HW), 100% data availability guarantee.

Huawei OceanStor Dorado

Model	Architecture	Max capacity	IOPS / Latency	Protocols	Use case
Dorado 8000/18000 V6	SmartMatrix full-mesh, up to 32 controllers	32 TB cache, 6400 SSD	40M IOPS, 0.05 ms	FC 32/64Gb, FC-NVMe, iSCSI, NFS, SMB, NVMe/RoCE, S3	Mission-critical, finance, govt, carrier
Dorado 8000/18000 V7 (2025)	SmartMatrix 4.0, up to 64/128 controllers	500 PB+	>100M IOPS, 0.03 ms	FC, RoCE, NVMe/TCP, NFS, SMB, S3	AI workloads, converged block/file/object

Key features: SmartMatrix survives 7/8 controllers, FlashEver (3-gen online HW upgrade in 10 years), RAID-TP (triple SSD failure), DPU-based SmartNIC, ML-based I/O prefetch, 100% ransomware detection (Tolly), #1 SPC-1 benchmark.

Dell PowerStore & PowerMax

Model	Architecture	Max capacity	IOPS / Latency	Protocols	Use case
PowerStore 1500/5500/9500 (Gen 3)	Active-active dual-node, PCIe Gen5, DDR5, RDMA 200GbE	1.2 PB raw, 5.8 PBe	3× IOPS vs Gen2	FC 32/64Gb, iSCSI, NVMe/FC, NVMe/TCP, NFSv4, SMB3	Midrange-to-high-end, VMware, containerized
PowerMax 2500/8500	Scale-out NVMe, Dynamic Fabric, up to 16 nodes	8.8 PBe (2500), 18 PBe (8500)	6 nines availability	FC 64Gb, FICON, NVMe/FC, NVMe/TCP, iSCSI, NFS, SMB	Mission-critical, mainframe, OLTP, cyber vault

Key features: PowerStore 6:1 DRR guarantee, unified block/file/vVols out of box, Cyber Detect AI anomaly; PowerMax 5:1 DRR, Secure Snapshots 65M, SRDF/Metro, Flexible RAID up to 92% efficient, FIPS 140-3.

HPE Alletra

Model	Architecture	Max capacity	IOPS / Latency	Protocols	Use case
Alletra 5000	Active-active hybrid flash, dual controller	1.2 PB raw	99.9999% guarantee	FC, iSCSI	Mixed primary + secondary, cost-efficient hybrid
Alletra 6000	Active-active all-NVMe, dual controller	~368 TB usable	<100 µs	FC, iSCSI	Business-critical DB, VDI, VMware
Alletra 9000	Active-active all-NVMe, multi-node scale-out	2–4 PB+ usable	~2–3M IOPS, <150 µs	FC, iSCSI, NVMe/FC	Mission-critical ERP, AI, consolidation
Alletra Storage MP	Disaggregated modular, block + file + object	5.8 PB block, 11.8 PB object	100% availability guarantee	FC, iSCSI, NVMe/FC, NFS, SMB, S3	Multi-protocol consolidation, AI/analytics

Key features: Triple Parity RAID (5000), InfoSight AI Ops, HPE GreenLake as-a-service, non-disruptive controller upgrades (MP), 100% data availability guarantee.

Infinidat

Model	Architecture	Max capacity	IOPS / Latency	Protocols	Use case
InfiniBox SSA G4	Triple-active controller, AMD EPYC PCIe 5.0, DDR5	1.97 PB usable / 5.9 PBe	2.24M IOPS, 35 µs	FC 32Gb, 25/100GbE, NVMe-oF/TCP, iSCSI, NFS, SMB, S3	Mission-critical Oracle/SQL, multi-site DR
InfiniBox G4 Hybrid	Triple-active hybrid (HDD + flash cache)	10.9 PB raw / 32.8 PBe	2.24M IOPS, 64 GB/s	FC, Ethernet, NVMe-oF, iSCSI, NFS, SMB, S3	Backup, massive unstructured data

Key features: Only 3-way active on the market, Neural Cache (ML-driven), InfiniRAID, Immutable snapshots, 100% availability + 1-min snapshot recovery guarantee, everything included in base price (no extra licensing).

Pure Storage FlashArray

Model	Architecture	Max capacity	IOPS / Latency	Protocols	Use case
FlashArray//X (X20–X90 R5)	Active-active, NVMe DirectFlash	1.2 PB raw / 4.4 PBe	250 µs, 5:1 DRR	FC, NVMe/FC, NVMe/RoCE, NVMe/TCP, iSCSI, NFS, SMB	Mission-critical DB, VMware, enterprise
FlashArray//C (C50–C90 R5)	Active-active, QLC DirectFlash	4.2 PB raw / 16.3 PBe	5:1 DRR	FC, NVMe-oF, iSCSI, NFS, SMB	Capacity-optimized, backup, file
FlashArray//XL (XL190)	Active-active, 40 DirectFlash modules	1.9 PB raw / 9.4 PBe	>4M IOPS, <100 µs, 45 GB/s	FC 64Gb, 100GbE RoCE, NVMe/FC, NVMe/TCP, NFS, SMB	Largest DB consolidation, OLTP

Key features: DirectFlash (no FTL layer), 99.9999% availability, Evergreen (never forklift upgrade), Purity OS unified across entire portfolio, ActiveCluster/ActiveDR, Pure1 AIOps.

Lenovo ThinkSystem

Model	Architecture	Max capacity	IOPS / Latency	Protocols	Use case
DM Series (DM3200F/5200F/7200F)	Active-active, all-NVMe, NetApp ONTAP	1.8 PB raw / 6.8 PBe	Up to 120 NVMe SSD	FC 64Gb, iSCSI, NVMe/FC, NFS, SMB, S3	Unified block/file, AI/ML, VMware
DG Series (DG5200/7200)	Active-active, all-QLC, ONTAP	7.4 PB raw / 27 PBe	QLC economics	FC, NVMe/FC, NVMe/TCP, iSCSI, NFS, SMB, S3	Capacity-optimized, backup, archive
DE Series (DE4000F–DE6600F)	Active-active, SAS/NVMe hybrid	1.84 PB raw	2M IOPS, <100 µs, 44 GB/s	FC 32Gb, iSCSI 25Gb, NVMe/FC, SAS, NVMe/RoCE	HPC, analytics, video surveillance

Key features: DM/DG use ONTAP (SnapMirror, SnapVault, FabricPool, RAID-DP/RAID-TEC); cluster scale-out up to 12 HA pairs; DE series best price/performance in portfolio.

Synology

Model	Architecture	Max capacity	Protocols	Use case
UC3200/UC3400	Active-active dual-controller, SAS backend	576 TB raw	iSCSI, FC 16Gb, 10/25GbE	SMB/midmarket SAN, VMware, HA
DS/RS Series (RS3626xs+, RS6426xs+)	Single-controller / HA pair, Btrfs	864 TB raw, 1 PB volume	SMB, NFS, iSCSI, FC (HBA)	SME all-in-one NAS/SAN, backup, surveillance

Key features: DSM UC for SAN, Synology HA, Snapshot Replication (16K snapshots), VMware VAAI/ODX/ALUA, Surveillance Station, low TCO.

Vendor comparison — overview

Vendor	Flagship	Max IOPS	Max capacity	Latency	Availability guarantee	Main differentiator
Hitachi	VSP 5600	33M	287 PBe	39 µs	8 nines (HW)	Mainframe + open; 65-node cluster
Huawei	Dorado 18000 V7	>100M	500 PB+	0.03 ms	99.99999%	SmartMatrix; #1 SPC-1
Dell	PowerMax 8500	—	18 PBe	—	6 nines	SRDF/Metro; mainframe
HPE	Alletra 9000/MP	~3M	11.8 PBe	<150 µs	100% data guarantee	InfoSight AIOps; GreenLake
Infinidat	InfiniBox SSA G4	2.24M	32.8 PBe	35 µs	100% availability	3-way active; Neural Cache
Pure	FlashArray//XL	>4M	16.3 PBe	<100 µs	99.9999%	DirectFlash; Evergreen
Lenovo	DM7200F	—	27 PBe	—	—	ONTAP ecosystem; broad portfolio
Synology	UC3400	690K	576 TB	—	—	Lowest price for active-active SAN

Storage selection by use case

Use case	Recommendation	Rationale
Mainframe + open hybrid	Hitachi VSP / Dell PowerMax	Only ones with FICON + FC simultaneously
AI/ML training	Huawei Dorado V7 / Pure //XL	Highest IOPS, lowest latency
Enterprise DB (Oracle, SQL Server)	Infinidat / Pure //X	Low latency, consistent performance
Virtualization (VMware, Hyper-V)	Dell PowerStore / HPE Alletra 6000	VAAI, vVols, InfoSight
SMB / SME	Synology / Lenovo DE	Low TCO, simple management
Object storage / backup	Pure //C / Lenovo DG / Infinidat Hybrid	QLC economics, high capacity
Multi-protocol consolidation	HPE Alletra MP / Huawei Dorado	Block + file + object in one platform

Decision diagram — storage platform selection

flowchart TD
    Start(["Storage requirement"]) --> PROTO{"Access type"}
    PROTO -->|"Block (SAN)"| BLOCK
    PROTO -->|"File (NAS)"| FILE
    PROTO -->|"Object"| OBJECT

    BLOCK --> BPERF{"Performance tier"}
    BPERF -->|"Tier 0/1<br/>< 100 µs, > 1M IOPS"| BT1["Infinidat / Pure //XL<br/>Huawei Dorado V7<br/>FC-NVMe, NVMe-oF"]
    BPERF -->|"Tier 2<br/>100-500 µs"| BT2["Dell PowerStore / HPE Alletra 6000<br/>Hitachi VSP / Lenovo DM<br/>FC 32G, iSCSI 25GbE"]
    BPERF -->|"Tier 3<br/>SME / low-cost"| BT3["Synology UC3400<br/>Lenovo DE / Dell PowerVault<br/>iSCSI, SAS"]

    BLOCK --> BECOS{"Ecosystem"}
    BECOS -->|"Mainframe"| BMF["Hitachi VSP / Dell PowerMax<br/>FICON + FC simultaneously"]
    BECOS -->|"VMware"| BVM["Dell PowerStore / HPE Alletra<br/>VAAI, vVols, InfoSight"]
    BECOS -->|"Oracle / SQL Server"| BDB["Infinidat / Pure //X<br/>Lowest latency"]

    FILE --> FSIZE{"Scaling"}
    FSIZE -->|"Enterprise"| FE["HPE Alletra MP (file)<br/>Lenovo DM / Dell PowerScale<br/>NFS, SMB, multi-protocol"]
    FSIZE -->|"SMB"| FS["Synology DS/RS<br/>Lenovo DE / TrueNAS<br/>Btrfs, NFS, SMB, low TCO"]

    OBJECT --> OUSE{"Use case"}
    OUSE -->|"Backup / archive"| OB["Pure //C / Infinidat Hybrid<br/>Lenovo DG<br/>QLC, erasure coding, low cost/TB"]
    OUSE -->|"AI/ML data lake"| OM["MinIO / Pure //C<br/>High throughput S3<br/>NVMe direct, erasure coding"]
    OUSE -->|"Kubernetes PVC"| OK["Ceph RBD / Longhorn / Linstor<br/>SDS on K8s<br/>CSI, replication, snapshots"]

OpenStack Storage

OpenStack offers three main storage services:

Service	Type	Description
Cinder	Block storage	Persistent volumes for instances (iSCSI, NFS, Ceph RBD)
Swift	Object storage	RESTful object store (S3-compatible via middleware)
Manila	File storage	Shared file systems (NFS, CIFS) as a managed service

Cinder (Block Storage)

Multi-backend support: LVM, Ceph RBD, NFS, iSCSI, Fibre Channel
Snapshoting, cloning, encryption at rest
Cinder scheduler for volume distribution across backends
QoS specs for IOPS/bandwidth limits

Swift (Object Storage)

Alternative to S3 for on-prem object storage
Ring-based data distribution (consistent hashing)
Multi-region replication (syncopy)
Stateless REST API (RESTful, no single point of failure)

Manila (Shared File Systems)

Managed NFS/CIFS for sharing between instances
Backends: NetApp, Dell EMC, CephFS, GlusterFS
Access rules (IP-based, cert-based, user-based)
Use case: HPC cluster home directories, NAS for legacy apps

Container storage (OpenStack + Ceph)

Ceph is the most common storage backend for OpenStack: Cinder (RBD), Swift (RGW), Manila (CephFS), Glance (RBD images).

Big Data storage

HDFS cluster

HDFS is the primary storage for the Hadoop ecosystem (on-prem). Typical configuration:

Parameter	Value	Note
Disk per DataNode	8–24 × HDD (14–22 TB) + 2× NVMe (metadata, cache)	Balance capacity / performance
Replication factor	3×	Rack-aware
Network	2× 25/100 GbE (data) + 1× 1 GbE (management)	Data + replication traffic
RAM	64–256 GB (OS cache + metadata)	HDFS cache + OS buffer cache
CPU	16–32 cores	HDFS overhead is low
NameNode HA	Active + Standby + JN (JournalNode)	Quorum-based HA
Use case	Sequential read/write, large files, Spark YARN

Model cluster — 1 PB usable:

10× DataNode (12× 18 TB HDD, 2× 1.9 TB NVMe)
2× NameNode (HA, 256 GB RAM)
3× JournalNode (small VMs)
Replication 3× → raw ~ 2.2 PB
Network: 25 GbE for data, 100 GbE for shuffle-heavy Spark

Object storage as Data Lake (S3/GCS/MinIO)

For new projects (Spark on K8s, Iceberg/Delta, lakehouse), object storage is preferred over HDFS:

Platform	Advantages	Limits
MinIO (on-prem)	S3 API, erasure coding, NVMe direct, high throughput	Single tenant (per cluster)
Pure //C (on-prem)	QLC NVMe, dedupe, S3 + NFS	Higher $/TB
AWS S3 (cloud)	Unlimited capacity, Iceberg/Delta support	Egress fees
Azure ADLS (cloud)	Hierarchical namespace, HNS, POSIX-like ACLs	Vendor lock
GCP GCS (cloud)	Uniform + fine-grained ACLs, object versioning	Region restrictions

Comparison: HDFS vs Object Storage for Big Data

Criteria	HDFS	Object Storage (S3/MinIO)
Architecture	Master/worker (NameNode SPOF)	Distributed, no SPOF (erasure coding)
Consistency	Strong (single writer per file)	Eventual (S3) / Strong (MinIO)
Throughput	High (rack-aware, locality)	High (network-bound)
Scaling	Horizontal (DataNode)	Horizontal (stateless)
Cost	Low (HDD)	Medium (S3 API)
Metadata	NameNode (1M blocks ~ 1 GB RAM)	Object-level (flat namespace)
Spark integration	Native (locality-optimized)	S3A connector, Hadoop Compatible
2026 trend	Legacy, declining	Standard for new projects

For more information about Big Data see BIG-DATA.en.md.

Sources

Links, books and standards: sources/infrastructure/sources.en.md

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