Troubleshooting iSCSI
ESXi systems include iSCSI technology to access remote storage using an IP network. You can use the vSphere Client, commands in the esxcli iscsi namespace, or the vicfg-iscsi command to configure both hardware and software iSCSI storage for your ESXi system.
Command Chart
VMware Link (Pages 53 onwards)
Storage Modules
The VMkernel is a high-performance operating system that runs directly on the ESXi host. The VMkernel manages most of the physical resources on the hardware, including memory, physical processors, storage, and networking controllers
To manage storage, VMkernel has a storage subsystem that supports several Host Bus Adapters (HBAs) including parallel SCSI, SAS, Fibre Channel, FCoE, and iSCSI. These HBAs connect a wide variety of active-active, active-passive, and ALUA storage arrays that are certified for use with the VMkernel.
The primary file system that the VMkernel uses is the VMware Virtual Machine File System (VMFS). VMFS is a cluster file system designed and optimized to support large files such as virtual disks and swap files. The VMkernel also supports the storage of virtual disks on NFS file systems.
The storage I/O path provides virtual machines with access to storage devices through device emulation. This device emulation allows a virtual machine to access files on a VMFS or NFS file system as if they were SCSI devices. The VMkernel provides storage virtualization functions such as the scheduling of I/O requests from multiple virtual machines and multipathing.
In addition, VMkernel offers several Storage APIs that enable storage partners to integrate and optimize their products for vSphere.
The following graphic illustrates the basics of the VMkernel core, with special attention to the storage stack. Storage‐related modules reside between the logical device I/O scheduler and the adapter I/O scheduler layerThe esxcli system module namespace allows you to view load and enable VMKernel modules.
To get an overview use this command:
Valid Commands
Note: With the release of 5.0, the majority of the legacy esxcfg-*/vicfg-* commands have been migrated over to esxcli. At some point, hopefully not in the distant future, esxcli will be parity complete and the esxcfg-*/vicfg-* commands will be completely deprecated and removed including the esxupdate/vihostupdate utilities.
What to use When
Examples
DCUI
You can also either connect to the console screen to look at Network Settings or connect via Putty/vMA/vCLI and type DCUI to get the following screen
ESXCLI and VICFG
Retrieving Network Port Information
Setting Virtual Switch Attributes
Listing, Creating and Deleting Standard Switches
Managing a VMKernel Port
Listing, Adding and Removing Port Groups
Configuring a PortGroup with a VLAN ID
Linking and Unlinking Uplink Adapters
Configure DNS and Routing
Managing uplinks in Distributed switches
Command Line reference
Command Line Interface – Getting Started
vCLI Poster of example commands
