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
Typically, you use VMFS datastores for most virtual disk storage. On certain occasions, you might use
raw LUNs or logical disks located in a SAN.
For example, you might use raw LUNs with RDMs in the following situations:
n
When SAN snapshot or other layered applications run in the virtual machine. The RDM enables
backup offloading systems by using features inherent to the SAN.
n
In any MSCS clustering scenario that spans physical hosts, such as virtual-to-virtual clusters and
physical-to-virtual clusters. In this case, cluster data and quorum disks are configured as RDMs rather
than as virtual disks on a shared VMFS.
Think of an RDM as a symbolic link from a VMFS volume to a raw LUN. The mapping makes LUNs
appear as files in a VMFS volume. The RDM, not the raw LUN, is referenced in the virtual machine
configuration. The RDM contains a reference to the raw LUN.
Two compatibility modes are available for RDMs:
n
In the virtual compatibility mode, the RDM acts like a virtual disk file. The RDM can use snapshots.
n
In the physical compatibility mode, the RDM offers direct access to the SCSI device for those
applications that require lower-level control.
Beneļ¬ts of Raw Device Mapping
An RDM provides a number of benefits, but it should not be used in every situation. In general, virtual disk
files are preferable to RDMs for manageability. However, when you need raw devices, you must use the
RDM.
RDM offers several benefits.
User-Friendly
Persistent Names
Provides a user-friendly name for a mapped device. When you use an
RDM, you do not need to refer to the device by its device name. You refer
to it by the name of the mapping file, for example:
/vmfs/volumes/myVolume/myVMDirectory/myRawDisk.vmdk
Dynamic Name
Resolution
Stores unique identification information for each mapped device. VMFS
associates each RDM with its current SCSI device, regardless of changes
in the physical configuration of the server because of adapter hardware
changes, path changes, device relocation, and so on.
Distributed File Locking Makes it possible to use VMFS distributed locking for raw SCSI devices.
Distributed locking on an RDM makes it safe to use a shared raw LUN
without losing data when two virtual machines on different servers try to
access the same LUN.
File Permissions Makes file permissions possible. The permissions of the mapping file are
enforced at file-open time to protect the mapped volume.
vSphere Storage
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