6.0.1
Table Of Contents
- vSphere Storage
- Contents
- About vSphere Storage
- Updated Information
- Introduction to Storage
- 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
- Dependent Hardware iSCSI Considerations
- Configure 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 Refresh and Rescan Operations
- Identifying Device Connectivity Problems
- Edit Configuration File Parameters
- Enable or Disable the Locator LED on Storage Devices
- Working with Flash Devices
- About VMware vSphere Flash Read Cache
- Working with Datastores
- Understanding VMFS Datastores
- Understanding Network File System Datastores
- Creating Datastores
- Managing Duplicate VMFS Datastores
- Upgrading 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
- Working with Virtual Volumes
- Virtual Machine Storage Policies
- Upgrading Legacy Storage Profiles
- Understanding Virtual Machine Storage Policies
- Working with Virtual Machine Storage Policies
- Creating and Managing VM Storage Policies
- Storage Policies and Virtual Machines
- Default Storage Policies
- 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
- Filtering Virtual Machine I/O
- VMkernel and Storage
- 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
- Storage Thick and Thin Provisioning
- Using Storage Providers
- Using vmkfstools
- vmkfstools Command Syntax
- vmkfstools Options
- -v Suboption
- File System Options
- Virtual Disk Options
- Supported Disk Formats
- Creating a Virtual Disk
- Example for Creating a Virtual Disk
- Initializing a Virtual Disk
- Inflating a Thin Virtual Disk
- Removing Zeroed Blocks
- Converting a Zeroedthick Virtual Disk to an Eagerzeroedthick Disk
- Deleting a Virtual Disk
- Renaming a Virtual Disk
- Cloning or Converting a Virtual Disk or RDM
- Example for Cloning or Converting a Virtual Disk
- Migrate Virtual Machines Between DifferentVMware Products
- Extending a Virtual Disk
- Upgrading Virtual Disks
- Creating a Virtual Compatibility Mode Raw Device Mapping
- Example for Creating a Virtual Compatibility Mode RDM
- 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
- Index
Storage Thick and Thin Provisioning 24
vSphere supports two models of storage provisioning, thick provisioning and thin provisioning.
Thick provisioning
It is a traditional model of storage provisioning. With thick provisioning,
large amount of storage space is provided in advance in anticipation of
future storage needs. However, the space might remain unused causing
underutilization of storage capacity.
Thin provisioning
This method contrast with thick provisioning and helps you eliminate
storage underutilization problems by allocating storage space in a exible
on-demand manner. With ESXi, you can use two models of thin
provisioning, array-level and virtual disk-level.
This chapter includes the following topics:
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“Storage Over-Subscription,” on page 269
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“Virtual Disk Thin Provisioning,” on page 269
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“Array Thin Provisioning and VMFS Datastores,” on page 273
Storage Over-Subscription
Thin provisioning allows you to report more virtual storage space than there is real physical capacity. This
discrepancy can lead to storage over-subscription, also called over-provisioning.
When you use thin provisioning, you should monitor actual storage usage to avoid conditions when you
run out of physical storage space.
Virtual Disk Thin Provisioning
When you create a virtual machine, a certain amount of storage space on a datastore is provisioned to
virtual disk les.
By default, ESXi oers a traditional storage provisioning method for virtual machines. With this method,
you rst estimate how much storage the virtual machine will need for its entire life cycle. You then provision
a xed amount of storage space to its virtual disk in advance, for example, 40GB, and have the entire
provisioned space commied to the virtual disk. A virtual disk that immediately occupies the entire
provisioned space is a thick disk.
ESXi supports thin provisioning for virtual disks. With the disk-level thin provisioning feature, you can
create virtual disks in a thin format. For a thin virtual disk, ESXi provisions the entire space required for the
disk’s current and future activities, for example 40GB. However, the thin disk uses only as much storage
space as the disk needs for its initial operations. In this example, the thin-provisioned disk occupies only
20GB of storage. As the disk requires more space, it can grow into its entire 40GB provisioned space.
VMware, Inc.
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