---
id: wiki-2026-0508-storage-area-networks
title: Storage Area Networks
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [SAN, Storage Area Network, Fibre Channel SAN]
duplicate_of: none
source_trust_level: A
confidence_score: 0.85
verification_status: applied
tags: [infrastructure, storage, san, fibre-channel, nvme-of]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: bash
  framework: linux-storage
---

# Storage Area Networks (SAN)

## 매 한 줄
> **"매 dedicated network 의 block-level storage — 매 servers 의 shared disk pool 의 access (LUN as local disk)"**. Fibre Channel (FC), iSCSI, NVMe-oF (over Fabrics) 의 protocol. 매 NAS (file-level) 와 대비. 2026 현재 매 NVMe/TCP, NVMe/RoCEv2 가 매 mainstream — 매 sub-100µs latency.

## 매 핵심

### 매 protocols
- **Fibre Channel (FC)**: 매 traditional, 32/64 Gbps, 매 dedicated hardware (HBA, FC switch).
- **iSCSI**: 매 SCSI over TCP/IP — 매 commodity ethernet, 매 cheap.
- **FCoE**: 매 FC over Ethernet — 매 declining.
- **NVMe-oF**: 매 NVMe command set, 매 sub-100µs.
  - *NVMe/FC*: NVMe over Fibre Channel.
  - *NVMe/RoCEv2*: NVMe over RDMA (lossless ethernet).
  - *NVMe/TCP*: NVMe over standard TCP — 매 mainstream 2026.

### 매 components
- **Initiator**: 매 server (HBA / NIC).
- **Target**: 매 storage array (LUN exposure).
- **Fabric**: 매 FC switch / Ethernet switch.
- **LUN (Logical Unit Number)**: 매 carved-out volume.
- **Zoning** (FC) / **VLAN+CHAP** (iSCSI): 매 access control.
- **Multipath I/O (MPIO)**: 매 redundant paths, 매 failover.

### 매 SAN vs NAS vs DAS
- **DAS**: 매 directly attached (USB, SATA) — 매 single server.
- **NAS**: 매 file-level (NFS, SMB) — 매 shared filesystem.
- **SAN**: 매 block-level — 매 OS 의 disk 의 보임.

### 매 응용
1. Enterprise virtualization (VMware vSphere VMFS).
2. Database (Oracle ASM, SQL Server cluster).
3. AI training (NVMe-oF flash array — Pure FlashBlade, NetApp).

## 💻 패턴

### Linux iSCSI initiator (open-iscsi)
```bash
sudo apt install open-iscsi
sudo iscsiadm -m discovery -t sendtargets -p 10.0.0.10:3260
sudo iscsiadm -m node --targetname iqn.2026-05.com.acme:lun0 \
    -p 10.0.0.10 --login
lsblk  # /dev/sdb appears as block device
```

### NVMe/TCP attach (Linux 6.x)
```bash
modprobe nvme-tcp
nvme discover -t tcp -a 10.0.0.20 -s 4420
nvme connect -t tcp -n nqn.2026-05.com.acme:nvme-subsys1 \
    -a 10.0.0.20 -s 4420
nvme list  # /dev/nvme1n1
```

### Multipath configuration (DM-Multipath)
```bash
# /etc/multipath.conf
defaults {
    user_friendly_names yes
    find_multipaths yes
    path_grouping_policy multibus
    failback immediate
}
# Apply
sudo multipath -r
multipath -ll
```

### LVM on SAN LUN
```bash
sudo pvcreate /dev/mapper/mpatha
sudo vgcreate vg_san /dev/mapper/mpatha
sudo lvcreate -L 500G -n lv_db vg_san
sudo mkfs.xfs /dev/vg_san/lv_db
```

### CHAP authentication (iSCSI)
```bash
# /etc/iscsi/iscsid.conf
node.session.auth.authmethod = CHAP
node.session.auth.username = iqn.2026-05.com.acme:initiator
node.session.auth.password = <secret>
```

### FC zoning (Brocade-like CLI)
```
zonecreate "zone_db1", "10:00:00:00:c9:aa:bb:cc; 50:06:01:6a:11:22:33:44"
cfgadd "cfg_prod", "zone_db1"
cfgenable "cfg_prod"
```

### Performance test (fio)
```bash
fio --name=san-test --filename=/dev/mapper/mpatha \
    --rw=randread --bs=4k --iodepth=64 --numjobs=8 \
    --runtime=60 --time_based --direct=1 --group_reporting
```

## 매 결정 기준
| 상황 | Approach |
|---|---|
| Ultra-low latency, AI/HPC | NVMe-oF (RoCEv2 or TCP) |
| Enterprise mixed workload | iSCSI 25/100 GbE |
| Legacy VMware / Oracle | Fibre Channel (32/64 Gbps) |
| Cloud-native | Object storage (S3) + EBS — 매 SAN 의 X |
| Small dev/test | NFS/SMB NAS or DAS |

**기본값**: 매 새 deployment → NVMe/TCP on 25/100 GbE. 매 FC 의 decline.

## 🔗 Graph
- 응용: [[Virtualization]]

## 🤖 LLM 활용
**언제**: enterprise on-prem block storage, low-latency shared storage 의 multiple servers.
**언제 X**: 매 cloud-native (use EBS/Persistent Disk), 매 single-server workload (DAS), 매 file sharing (NAS).

## ❌ 안티패턴
- **No multipath**: 매 single switch failure → outage.
- **iSCSI on shared VLAN**: 매 contention. 매 dedicated VLAN/network 의 사용.
- **No zoning**: 매 LUN 의 모든 host 의 visible — 매 corruption risk.
- **FC for greenfield**: 매 NVMe/TCP 의 cheaper, 매 faster.

## 🧪 검증 / 중복
- Verified (SNIA standards; Linux NVMe-oF docs; vendor docs Pure/NetApp 2025).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — SAN protocols incl. NVMe-oF mainstream patterns |
