6.7
Table Of Contents
- vSphere Storage
- Contents
- About vSphere Storage
- 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 Recommendations and Restrictions
- Configuring iSCSI Parameters for Adapters
- Set Up Independent Hardware iSCSI Adapters
- Configure Dependent Hardware iSCSI Adapters
- Configure the Software iSCSI Adapter
- Configure iSER Adapters
- Modify General Properties for iSCSI or iSER Adapters
- Setting Up Network for iSCSI and iSER
- 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
- 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
- Upgrading 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
- Failovers with Fibre Channel
- Host-Based Failover with iSCSI
- Array-Based Failover with iSCSI
- Path Failover and Virtual Machines
- Pluggable Storage Architecture and Path Management
- Viewing and Managing Paths
- Using Claim Rules
- Scheduling Queues for Virtual Machine I/Os
- Raw Device Mapping
- Storage Policy Based Management
- Virtual Machine Storage Policies
- Workflow for Virtual Machine Storage Policies
- Populating the VM Storage Policies Interface
- About Rules and Rule Sets
- Creating and Managing VM Storage Policies
- About Storage Policy Components
- Storage Policies and Virtual Machines
- Default Storage Policies
- 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
- Troubleshooting 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
Sparse disks use the copy-on-write mechanism, in which the virtual disk contains no data, until the data is
copied there by a write operation. This optimization saves storage space.
Depending on the type of your datastore, delta disks use different sparse formats.
Snapshot Formats VMFS5 VMFS6
VMFSsparse For virtual disks smaller than 2 TB. N/A
SEsparse For virtual disks larger than 2 TB. For all disks.
VMFSsparse VMFS5 uses the VMFSsparse format for virtual disks smaller than 2 TB.
VMFSsparse is implemented on top of VMFS. The VMFSsparse layer
processes I/Os issued to a snapshot VM. Technically, VMFSsparse is a
redo-log that starts empty, immediately after a VM snapshot is taken. The
redo-log expands to the size of its base vmdk, when the entire vmdk is
rewritten with new data after the VM snapshotting. This redo-log is a file in
the VMFS datastore. Upon snapshot creation, the base vmdk attached to
the VM is changed to the newly created sparse vmdk.
SEsparse SEsparse is a default format for all delta disks on the VMFS6 datastores.
On VMFS5, SEsparse is used for virtual disks of the size 2 TB and larger.
SEsparse is a format similar to VMFSsparse with some enhancements.
This format is space efficient and supports the space reclamation
technique. With space reclamation, blocks that the guest OS deletes are
marked. The system sends commands to the SEsparse layer in the
hypervisor to unmap those blocks. The unmapping helps to reclaim space
allocated by SEsparse once the guest operating system has deleted that
data. For more information about space reclamation, see Storage Space
Reclamation.
Snapshot Migration
You can migrate VMs with snapshots across different datastores. The following considerations apply:
n
If you migrate a VM with the VMFSsparse snapshot to VMFS6, the snapshot format changes to
SEsparse.
n
When a VM with a vmdk of the size smaller than 2 TB is migrated to VMFS5, the snapshot format
changes to VMFSsparse.
n
You cannot mix VMFSsparse redo-logs with SEsparse redo-logs in the same hierarchy.
Upgrading VMFS Datastores
ESXi uses different approaches to VMFS5 and VMFS3 upgrades.
vSphere Storage
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