6.5.1
Table Of Contents
- vSphere Storage
- Contents
- About vSphere Storage
- Updated Information
- Introduction to Storage
- Getting Started with a Traditional Storage Model
- Overview of Using ESXi with a SAN
- Using ESXi with Fibre Channel SAN
- Configuring Fibre Channel Storage
- Configuring Fibre Channel over Ethernet
- Booting ESXi from Fibre Channel SAN
- Booting ESXi with Software FCoE
- Best Practices for Fibre Channel Storage
- Using ESXi with iSCSI SAN
- Configuring iSCSI Adapters and Storage
- ESXi iSCSI SAN Requirements
- ESXi iSCSI SAN Restrictions
- Setting LUN Allocations for iSCSI
- Network Configuration and Authentication
- Set Up Independent Hardware iSCSI Adapters
- About Dependent Hardware iSCSI Adapters
- About the Software iSCSI Adapter
- Modify General Properties for iSCSI Adapters
- Setting Up iSCSI Network
- Using Jumbo Frames with iSCSI
- Configuring Discovery Addresses for iSCSI Adapters
- Configuring CHAP Parameters for iSCSI Adapters
- Configuring Advanced Parameters for iSCSI
- iSCSI Session Management
- Booting from iSCSI SAN
- Best Practices for iSCSI Storage
- Managing Storage Devices
- Storage Device Characteristics
- Understanding Storage Device Naming
- Storage Rescan Operations
- Identifying Device Connectivity Problems
- Edit Configuration File Parameters
- Enable or Disable the Locator LED on Storage Devices
- Erase Storage Devices
- Working with Flash Devices
- About VMware vSphere Flash Read Cache
- Working with Datastores
- Types of Datastores
- Understanding VMFS Datastores
- Understanding Network File System Datastores
- Creating Datastores
- Managing Duplicate VMFS Datastores
- Increasing VMFS Datastore Capacity
- Administrative Operations for Datastores
- Set Up Dynamic Disk Mirroring
- Collecting Diagnostic Information for ESXi Hosts on a Storage Device
- Checking Metadata Consistency with VOMA
- Configuring VMFS Pointer Block Cache
- Understanding Multipathing and Failover
- Raw Device Mapping
- Software-Defined Storage and Storage Policy Based Management
- About Storage Policy Based Management
- Virtual Machine Storage Policies
- Working with Virtual Machine Storage Policies
- Populating the VM Storage Policies Interface
- Default Storage Policies
- Creating and Managing VM Storage Policies
- Storage Policies and Virtual Machines
- Assign Storage Policies to Virtual Machines
- Change Storage Policy Assignment for Virtual Machine Files and Disks
- Monitor Storage Compliance for Virtual Machines
- Check Compliance for a VM Storage Policy
- Find Compatible Storage Resource for Noncompliant Virtual Machine
- Reapply Virtual Machine Storage Policy
- Using Storage Providers
- Working with Virtual Volumes
- About Virtual Volumes
- Virtual Volumes Concepts
- Virtual Volumes and Storage Protocols
- Virtual Volumes Architecture
- Virtual Volumes and VMware Certificate Authority
- Snapshots and Virtual Volumes
- Before You Enable Virtual Volumes
- Configure Virtual Volumes
- Provision Virtual Machines on Virtual Volumes Datastores
- Virtual Volumes and Replication
- Best Practices for Working with vSphere Virtual Volumes
- Filtering Virtual Machine I/O
- Storage Hardware Acceleration
- Hardware Acceleration Benefits
- Hardware Acceleration Requirements
- Hardware Acceleration Support Status
- Hardware Acceleration for Block Storage Devices
- Hardware Acceleration on NAS Devices
- Hardware Acceleration Considerations
- Thin Provisioning and Space Reclamation
- Using vmkfstools
- vmkfstools Command Syntax
- The vmkfstools Command Options
- -v Suboption
- File System Options
- Virtual Disk Options
- Supported Disk Formats
- Creating a Virtual Disk
- Initializing a Virtual Disk
- Inflating a Thin Virtual Disk
- Converting a Zeroedthick Virtual Disk to an Eagerzeroedthick Disk
- Removing Zeroed Blocks
- Deleting a Virtual Disk
- Renaming a Virtual Disk
- Cloning or Converting a Virtual Disk or RDM
- Extending a Virtual Disk
- Upgrading Virtual Disks
- Creating a Virtual Compatibility Mode Raw Device Mapping
- Creating a Physical Compatibility Mode Raw Device Mapping
- Listing Attributes of an RDM
- Displaying Virtual Disk Geometry
- Checking and Repairing Virtual Disks
- Checking Disk Chain for Consistency
- Storage Device Options
Enabling header and data digests does require additional processing for both the initiator and the target
and can affect throughput and CPU use performance.
Note Systems that use the Intel Nehalem processors offload the iSCSI digest calculations, as a result,
reducing the impact on performance.
For information on enabling header and data digests, see Configuring Advanced Parameters for iSCSI.
How Virtual Machines Access Data on an iSCSI SAN
ESXi stores a virtual machine's disk files within a VMFS datastore that resides on a SAN storage device.
When virtual machine guest operating systems send SCSI commands to their virtual disks, the SCSI
virtualization layer translates these commands to VMFS file operations.
When a virtual machine interacts with its virtual disk stored on a SAN, the following process takes place:
1 When the guest operating system in a virtual machine reads or writes to SCSI disk, it sends SCSI
commands to the virtual disk.
2 Device drivers in the virtual machine’s operating system communicate with the virtual SCSI
controllers.
3 The virtual SCSI controller forwards the commands to the VMkernel.
4 The VMkernel performs the following tasks.
a Locates an appropriate virtual disk file in the VMFS volume.
b Maps the requests for the blocks on the virtual disk to blocks on the appropriate physical device.
c Sends the modified I/O request from the device driver in the VMkernel to the iSCSI initiator
(hardware or software).
5 If the iSCSI initiator is a hardware iSCSI adapter, both independent or dependent, the adapter
performs the following tasks.
a Encapsulates I/O requests into iSCSI Protocol Data Units (PDUs).
b Encapsulates iSCSI PDUs into TCP/IP packets.
c Sends IP packets over Ethernet to the iSCSI storage system.
6 If the iSCSI initiator is a software iSCSI adapter, the following takes place.
a The iSCSI initiator encapsulates I/O requests into iSCSI PDUs.
b The initiator sends iSCSI PDUs through TCP/IP connections.
c The VMkernel TCP/IP stack relays TCP/IP packets to a physical NIC.
d The physical NIC sends IP packets over Ethernet to the iSCSI storage system.
7 Ethernet switches and routers on the network carry the request to the appropriate storage device.
vSphere Storage
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