Block storage carried over its own dedicated network, typically iSCSI or Fibre Channel, which gives ESX hosts LUNs to format as VMFS datastores.
Also called storage area network.
Read more: Broadcom TechDocs
In the Ultra Transcenders books
Each book explains SAN in context, with comparison tables and the common traps.
Terms in this definition
- General-purpose v1
The older storage account kind (
Storage), which lacks access tiers, Archive and premium file shares and retires on 13 October 2026. Converting to ZRS requires first upgrading to GPv2, a one-way change. - OVER
Gives a T-SQL window function its window: PARTITION BY, ORDER BY and, if wanted, a ROWS or RANGE frame. Rankings and running totals can then be worked out while every row is kept.
- Dedicated
Running Azure Functions on an App Service plan, which removes the execution time limit and offers VNet integration on Basic and higher tiers.
- iSCSI
Protocol that carries block storage over TCP on port 3260. When recovering files, Azure Backup's script mounts recovery point disks as local volumes using it.
- FC
Fibre Channel, a SAN protocol for block storage. VCF clusters may use VMFS over it as principal storage.
- ESX
VMware's bare-metal hypervisor, installed on each host in a VCF fleet. Up to version 9.0 it was known as ESXi.
- FORMAT
A DAX function that turns a value into text according to a format string, for instance "MMMM" to show a month's name. Since the output is text, numeric operations can't use it, and dynamic format strings were introduced to get around that.
- VMFS
Clustered file system for block datastores, whether the storage is iSCSI, local or FC-attached. Unlike VMFS5, VMFS6 can use 4Kn devices and reclaims freed space by itself.
Related terms
- MPIO
Multipath I/O: a Windows Server feature that reaches the same SAN LUN over more than one physical route, such as several HBAs or iSCSI sessions, to provide failover and spread load, via the Microsoft DSM or one supplied by the storage vendor.
- ODX
Offloaded Data Transfer. A capable SAN moves or copies data internally, exchanging tokens rather than streaming it through the server; NTFS supports it but ReFS doesn't.
- Subject alternative name
The part of a certificate (SAN) that names each host it is good for. Microsoft Tunnel Gateway needs its FQDN or IP address there, and SCEP or PKCS profiles can supply extra values.