2nd/10_Wiki/Topics/Architecture/Storage-Area-Networks.md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

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

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)

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)

# /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

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)

# /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)

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