knowledge-base/STORAGE.md

# 💾 Storage infrastruktura

## Typy úložišť

| Typ | Popis | Latence | Use case |
|-----|-------|---------|----------|
| **DAS** (Direct Attached) | Disky přímo v serveru | <0.1 ms | OS, cache, lokální data |
| **SAN** (Storage Area Network) | Bloková zařízení po síti | <1 ms | Databáze, VM datastory |
| **NAS** (Network Attached Storage) | Souborový přístup (NFS, SMB) | 1-3 ms | Sdílené soubory, home dirs |
| **Object storage** | REST API, flat namespace | 10-100 ms | Zálohy, media, big data |

## Protokoly

| Protokol | Typ | Rychlost | Poznámka |
|----------|-----|----------|----------|
| **Fibre Channel** | SAN | 8/16/32/64 Gbps | Nízká latence, dedikovaná síť |
| **iSCSI** | SAN (IP) | 1/10/25 GbE | Levnější, po ethernetu |
| **NVMe-oF** | SAN (NVMe) | 25/50/100 GbE | Nejnižší latence, emerging |
| **NFS** | NAS | 1/10/25 GbE | Univerzální, jednoduchý |
| **SMB/CIFS** | NAS | 1/10/25 GbE | Windows native |
| **S3 API** | Object | — | Standard pro object storage |

## RAID

| RAID | Min. disků | Kapacita | Ochrana | Rychlost čtení | Rychlost zápisu | Use case |
|------|-----------|----------|---------|---------------|----------------|----------|
| **0** | 2 | 100 % | Žádná | N × (striping) | N × | Temp data, cache (risky) |
| **1** | 2 | 50 % | 1 disk | N × (mirror) | 1 × | OS disk, kritická data |
| **5** | 3 | 67-94 % | 1 disk | N-1 × | N-1 × (parity write penalty) | Univerzální file/VM storage |
| **6** | 4 | 50-88 % | 2 disky | N-2 × | N-2 × (double parity) | Velké kapacity, důležitá data |
| **10** | 4 | 50 % | 1/mirror | N × | N/2 × | Databáze, 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

- Malý stripe (16-64 KB) — lepší IOPS, horší throughput (databáze, OLTP)
- Velký stripe (128-1024 KB) — lepší throughput, horší IOPS (video, media, backup)
- Write hole u RAID 5/6: při výpadku během zápisu parity je metadata nekonzistentní (prevence: non-volatile cache, battery-backed RAID controller)

## Software-Defined Storage (SDS)

| Nástroj | Typ | Use case |
|---------|-----|----------|
| **Ceph** | Object/Block/File (RADOS) | Univerzální 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, mikroservisy |
| **Linstor** | Block (DRBD + LVM) | Linux SDS, Kubernetes |
| **VMware vSAN** | Block (HCI) | VMware ecosystem |
| **StarWind** | Block (HCI) | Hyper-V / VMware |

### Ceph

**Architektura**:

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

**CRUSH map** (Controlled Replication Under Scalable Hashing):

- Algoritmus pro výpočet umístění dat (žádný centrální index)
- Vrstvy: Root → Datacenter → Rack → Host → OSD
- Failure domain: replikace napříč racky / hosty
- `ceph osd crush rule create-replicated replicated_rule default host`

**Přístupová rozhraní**:

| Rozhraní | Typ | Use case |
|----------|-----|----------|
| **RBD** (RADOS Block Device) | Block | VM images, Kubernetes PVC (csi-rbd) |
| **RGW** (RADOS Gateway) | Object (S3/Swift API) | S3-kompatibilní storage, backup |
| **CephFS** | File (POSIX) | Shared filesystem, home dirs |
| **NFS-Ganesha** | File (NFS) | NFS export přes CephFS |

**Erasure coding**:

- K+M (data + parity chunks), např. 8+3 (8 data, 3 parity)
- Prostorově efektivnější než 3× replikace (1.375× vs 3×)
- Vyšší CPU režie, nižší IOPS
- Doporučeno pro cold data (RGW) místo replikace

## Výrobci enterprise storage

### Hitachi VSP (Virtual Storage Platform)

| Model | Architektura | Max kapacita | IOPS / Latence | Protokoly | Use case |
|-------|-------------|--------------|----------------|-----------|----------|
| **VSP 5200/5600** | Active-active, scale-up/out, 2–12 controllerů | 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, až 65 nodů/130 controllerů | 10.62 PB raw (E1090) | 8.4M IOPS, <41 µs | FC 32Gb, iSCSI 25Gb, FC-NVMe 32Gb | Midrange enterprise, hybrid workloads |

**Klíčové vlastnosti**: SVOS společný pro celé portfolio, AI-driven data reduction 4:1 garance, Global-Active Device metro clustering, 8 nines availability (HW), 100% data availability guarantee.

---

### Huawei OceanStor Dorado

| Model | Architektura | Max kapacita | IOPS / Latence | Protokoly | Use case |
|-------|-------------|--------------|----------------|-----------|----------|
| **Dorado 8000/18000 V6** | SmartMatrix full-mesh, až 32 controllerů | 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, až 64/128 controllerů | 500 PB+ | >100M IOPS, 0.03 ms | FC, RoCE, NVMe/TCP, NFS, SMB, S3 | AI workloads, converged block/file/object |

**Klíčové vlastnosti**: SmartMatrix přežije 7/8 controllerů, FlashEver (3-gen online HW upgrade za 10 let), 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 | Architektura | Max kapacita | IOPS / Latence | Protokoly | 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 oproti 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, až 16 nodů | 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 |

**Klíčové vlastnosti**: PowerStore 6:1 DRR garance, unified block/file/vVols out of box, Cyber Detect AI anomaly; PowerMax 5:1 DRR, Secure Snapshots 65M, SRDF/Metro, Flexible RAID až 92% efficient, FIPS 140-3.

---

### HPE Alletra

| Model | Architektura | Max kapacita | IOPS / Latence | Protokoly | Use case |
|-------|-------------|--------------|----------------|-----------|----------|
| **Alletra 5000** | Active-active hybrid flash, dual controller | 1.2 PB raw | 99.9999% garance | 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 garance | FC, iSCSI, NVMe/FC, NFS, SMB, S3 | Multi-protocol consolidation, AI/analytics |

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

---

### Infinidat

| Model | Architektura | Max kapacita | IOPS / Latence | Protokoly | 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 |

**Klíčové vlastnosti**: 3-way active jediný na trhu, Neural Cache (ML-driven), InfiniRAID, Immutable snapshots, 100% availability + 1-min snapshot recovery garance, vše v základní ceně (žádný extra licensing).

---

### Pure Storage FlashArray

| Model | Architektura | Max kapacita | IOPS / Latence | Protokoly | 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 modulů | 1.9 PB raw / 9.4 PBe | >4M IOPS, <100 µs, 45 GB/s | FC 64Gb, 100GbE RoCE, NVMe/FC, NVMe/TCP, NFS, SMB | Největší DB konsolidace, OLTP |

**Klíčové vlastnosti**: DirectFlash (bez FTL vrstvy), 99.9999% availability, Evergreen (nikdy forklift upgrade), Purity OS jednotný napříč celým portfoliem, ActiveCluster/ActiveDR, Pure1 AIOps.

---

### Lenovo ThinkSystem

| Model | Architektura | Max kapacita | IOPS / Latence | Protokoly | Use case |
|-------|-------------|--------------|----------------|-----------|----------|
| **DM Series** (DM3200F/5200F/7200F) | Active-active, all-NVMe, NetApp ONTAP | 1.8 PB raw / 6.8 PBe | Až 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 ekonomie | 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 |

**Klíčové vlastnosti**: DM/DG využívají ONTAP (SnapMirror, SnapVault, FabricPool, RAID-DP/RAID-TEC); cluster scale-out až 12 HA párů; DE série nejlepší poměr cena/výkon v portfoliu.

---

### Synology

| Model | Architektura | Max kapacita | Protokoly | 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 |

**Klíčové vlastnosti**: DSM UC pro SAN, Synology HA, Snapshot Replication (16K snapshots), VMware VAAI/ODX/ALUA, Surveillance Station, nízké TCO.

---

### Srovnání vendorů — přehled

| Vendor | Flagship | Max IOPS | Max kapacita | Latence | Garance availability | Hlavní diferentiátor |
|--------|----------|----------|-------------|---------|---------------------|----------------------|
| **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; široké portfolio |
| **Synology** | UC3400 | 690K | 576 TB | — | — | Nejnižší cena za active-active SAN |

---

### Výběr storage dle use case

| Use case | Doporučení | Zdůvodnění |
|----------|-----------|-------------|
| **Mainframe + open hybrid** | Hitachi VSP / Dell PowerMax | Jediní s FICON + FC současně |
| **AI/ML trénování** | Huawei Dorado V7 / Pure //XL | Nejvyšší IOPS, nejnižší latence |
| **Enterprise DB (Oracle, SQL Server)** | Infinidat / Pure //X | Nízká latence, konzistentní výkon |
| **Virtualizace (VMware, Hyper-V)** | Dell PowerStore / HPE Alletra 6000 | VAAI, vVols, InfoSight |
| **SMB / SME** | Synology / Lenovo DE | Nízké TCO, jednoduchá správa |
| **Object storage / backup** | Pure //C / Lenovo DG / Infinidat Hybrid | QLC ekonomie, vysoká kapacita |
| **Multi-protocol konsolidace** | HPE Alletra MP / Huawei Dorado | Block + file + object v jedné platformě |

## Decision diagram — výběr storage platformy

```mermaid
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 současně"]
    BECOS -->|"VMware"| BVM["Dell PowerStore / HPE Alletra<br/>VAAI, vVols, InfoSight"]
    BECOS -->|"Oracle / SQL Server"| BDB["Infinidat / Pure //X<br/>Nejnižší latence"]

    FILE --> FSIZE{"Škálování"}
    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, nízké TCO"]

    OBJECT --> OUSE{"Use case"}
    OUSE -->|"Backup / archive"| OB["Pure //C / Infinidat Hybrid<br/>Lenovo DG<br/>QLC, erasure coding, nízká cena/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 na K8s<br/>CSI, replication, snapshots"]
```

## OpenStack Storage

OpenStack nabízí tři hlavní storage služby:

| Služba | Typ | Popis |
|--------|-----|-------|
| **Cinder** | Block storage | Persistent volumes pro instance (iSCSI, NFS, Ceph RBD) |
| **Swift** | Object storage | RESTful object store (S3-kompatibilní via middleware) |
| **Manila** | File storage | Shared file systems (NFS, CIFS) jako managed service |

### Cinder (Block Storage)

- Podpora multi-backend: LVM, Ceph RBD, NFS, iSCSI, Fibre Channel
- Snapshoting, cloning, encryption at rest
- Cinder scheduler pro distribuci volume napříč backendy
- QoS specs pro omezení IOPS/bandwidth

### Swift (Object Storage)

- Alternativa k S3 pro on-prem object storage
- Ring-based data distribution (consistent hashing)
- Multi-region replikace (syncopy)
- Stateless REST API (RESTful, no single point of failure)

### Manila (Shared File Systems)

- Managed NFS/CIFS pro sdílení mezi instancemi
- Backendy: NetApp, Dell EMC, CephFS, GlusterFS
- Access rules (IP-based, cert-based, user-based)
- Use case: HPC cluster home directories, NAS pro legacy apps

### Kontejnerový storage (OpenStack + Ceph)

Ceph je nejčastější storage backend pro OpenStack: Cinder (RBD), Swift (RGW), Manila (CephFS), Glance (RBD images).

## Big Data storage

### HDFS cluster

HDFS je primární storage pro Hadoop ekosystém (on-prem). Typická konfigurace:

| Parametr | Hodnota | Poznámka |
|----------|---------|----------|
| **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 je nízký |
| **NameNode HA** | Active + Standby + JN (JournalNode) | Quorum-based HA |
| **Use case** | Secvenční čtení/zápis, velké soubory, Spark YARN |

**Modelový cluster — 1 PB usable:**

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

### Object storage jako Data Lake (S3/GCS/MinIO)

Pro nové projekty (Spark on K8s, Iceberg/Delta, lakehouse) se preferuje object storage před HDFS:

| Platforma | Výhody | Limity |
|-----------|--------|--------|
| **MinIO** (on-prem) | S3 API, erasure coding, NVMe direct, high throughput | Single tenant (per cluster) |
| **Pure //C** (on-prem) | QLC NVMe, dedupe, S3 + NFS | Vyšší cena/TB |
| **AWS S3** (cloud) | Neomezená kapacita, 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 |

### Srovnání: HDFS vs Object Storage pro Big Data

| Kritérium | HDFS | Object Storage (S3/MinIO) |
|-----------|------|-------------------------|
| **Architektura** | Master/worker (NameNode SPOF) | Distributed, no SPOF (erasure coding) |
| **Konzistence** | Strong (jediný writer per file) | Eventual (S3) / Strong (MinIO) |
| **Propustnost** | Vysoká (rack-aware, locality) | Vysoká (network-bound) |
| **Škálování** | Horizontální (DataNode) | Horizontální (stateless) |
| **Cena** | Nízká (HDD) | Střední (S3 API) |
| **Metadata** | NameNode (1 mil. bloků ~ 1 GB RAM) | Object-level (flat namespace) |
| **Spark integration** | Native (locality optimalizace) | S3A connector, Hadoop Compatible |
| **2026 trend** | Legacy, klesající | Standard pro nové projekty |

Podrobnější informace o Big Data viz [BIG-DATA.md](BIG-DATA.md).

## Zdroje

Odkazy, knihy a standardy: [sources/infrastructure/sources.md](sources/infrastructure/sources.md)

### Doporučená literatura

| Kniha | Autoři | ISBN | Popis |
|-------|--------|------|-------|
| Storage Systems | Ganger, Gibson | 978-1680837540 | Učebnice pokrývající návrh, implementaci a provoz úložných systémů — od charakteristik jednotlivých zařízení přes OS, databáze a networking až po distribuce v serverech a large-scale systémech. Nezbytný zdroj pro architekty storage infrastruktury. |

*Poslední revize: 2026-06-03*