Small Computer System Interface, a standard for connecting disks. Hyper-V lets you hot-add or remove virtual SCSI disks on a running VM, and generation 2 VMs start up from them.
Also called Small Computer System Interface.
In the Ultra Transcenders books
Each book explains SCSI in context, with comparison tables and the common traps.
Terms in this definition
- Standard deployment type
A Foundry deployment type billed per token that keeps processing of prompts and responses inside the Azure geography of the resource, meeting data residency needs at lower volumes.
- Hyper-V
The hypervisor built into Windows. The VMs for the Azure Extended Network appliance require the Hyper-V role, using nested virtualisation, and an external virtual switch for each NIC.
- Virtual machines
Infrastructure-as-a-service compute giving complete control of the operating system, making it a fit for lift-and-shift moves and for software relying on OS-level pieces like COM.
Related terms
- NMP
Handles failover and path choice for SCSI storage through two kinds of submodule, SATP and PSP, and is VMware's default multipathing module. For NVMe devices, HPP is used instead.
- Protocol endpoint
With vVols, ESX hosts do not talk to each virtual volume directly; I/O passes through a logical proxy on the storage array, presented as a mount point for NFS or as a proxy LUN for SCSI transports.
- RDM
Lets a VM use a physical LUN directly, through a mapping file stored on VMFS. Physical compatibility mode passes SCSI commands straight to the device, at the cost of VM snapshot support.
- Space reclamation
Handing blocks that are no longer in use, after files are deleted on the datastore or inside a guest, back to the storage array using SCSI UNMAP. VMFS6 does it automatically; earlier VMFS versions relied on running an esxcli command by hand.
- UEFI
The modern firmware standard that took over from BIOS. Because Hyper-V generation 2 machines use it, they can start up from a virtual SCSI disk and have Secure Boot switched on.