- What's New
- Function Overview
- Service Overview
- Getting Started
-
User Guide
- Permissions Management
- Purchasing and Using an EVS Disk
- Attaching an Existing EVS Disk
- Viewing EVS Disk Details
- Changing the EVS Disk Type (OBT)
- Expanding EVS Disk Capacity
- Detaching and Deleting an EVS Disk
- Managing EVS Recycle Bin
-
Managing EVS Snapshots
- EVS Snapshot Overview
-
Using EVS Snapshots
- Creating an EVS Snapshot
- Rolling Back Disk Data from a Snapshot
- Creating a Disk from a Snapshot
- Enabling or Disabling Instant Snapshot Restore (for Snapshots in Commercial Use)
- Checking the EVS Snapshot Storage Usage (for Snapshots in Commercial Use)
- Checking EVS Snapshot Details
- Deleting an EVS Snapshot
- Managing Encrypted EVS Disks
- Managing Shared EVS Disks
- Managing EVS Disk Backups
- Managing EVS Transfers
- Managing EVS Tags
- Managing EVS Quotas
- Cloud Eye Monitoring
- Recording EVS Operations Using CTS
- Best Practices
-
API Reference
- Before You Start
- API Overview
- Calling APIs
- Getting Started
- API Version Query
-
API
-
Disk Management
- Creating EVS Disks
- Updating an EVS Disk
- Querying Details About All EVS Disks
- Querying Details About an EVS Disk
- Expanding Capacity of an EVS Disk
- Deleting an EVS Disk
- Creating EVS Disks (Deprecated)
- Querying EVS Disks (Deprecated)
- Expanding Capacity of an EVS Disk (Deprecated)
- Unsubscribing from Yearly/Monthly EVS Disks
- Querying Details About All EVS Disks (Deprecated)
- Querying Details About an EVS Disk (Deprecated)
- Modifying QoS of an EVS Disk
- Snapshot Management
- Tag Management
- Task Management
-
Disk Management
-
Cinder API
-
Disk Management
- Creating EVS Disks
- Deleting an EVS Disk
- Updating an EVS Disk
- Querying EVS Disk Types
- Querying Details About an EVS Disk Type
- Querying EVS Disks
- Querying Details About an EVS Disk
- Querying Details About All EVS Disks
- Querying Extension APIs
- Expanding Capacity of an EVS Disk
- Setting Bootable Flag for an EVS Disk
- Setting Read-Only Flag for an EVS Disk
- Exporting EVS Disk Data as an Image
- Attaching an EVS Disk (Deprecated)
- Detaching an EVS Disk (Deprecated)
- Reserving an EVS Disk (Deprecated)
- Canceling Reservation of an EVS Disk (Deprecated)
- Snapshot Management
- Quota Management
- Disk Transfer Management
- Disk Metadata Management
- Snapshot Metadata Management
- API Version Query
- AZ Query
-
Disk Management
-
Out-of-Date APIs
- API
-
Cinder API
-
Disk Management
- Querying Details About an EVS Disk (Deprecated)
- Creating EVS Disks
- Querying Details About All EVS Disks
- Deleting an EVS Disk
- Updating an EVS Disk
- Querying EVS Disk Types
- Querying Details About an EVS Disk Type
- Querying EVS Disks
- Querying Details About an EVS Disk
- Querying Extension APIs
- Expanding Capacity of an EVS Disk
- Setting Bootable Flag for an EVS Disk
- Exporting EVS Disk Data as an Image
- Setting Read-Only Flag for an EVS Disk
- Snapshot Management
- Quota Management
- Disk Metadata Management
- Snapshot Metadata Management
- Querying AZs
-
Disk Management
- Permissions and Supported Actions
- Appendix
- Change History
- SDK Reference
-
FAQs
- Summary
-
General
- How Do I Start Using a Newly Purchased Disk?
- Can EVS Disks Be Used Directly for Storage?
- Can EVS Disks Be Used Alone?
- How Can I View My Disk Details?
- How Do I Change the Name of My Disk?
- Can I Change the AZ of My Disk?
- Can I Change the Disk Type, Device Type, or Sharing Attribute of My Disk?
- What Should I Do If an Error Occurs on My EVS Disk?
- How Can I Obtain ECS NIC Information?
- Why Do Some of My EVS Disks Not Have WWN Information?
- How Can I Migrate Data from an EVS Disk?
- What Are the Differences Between System Disks and Data Disks?
- Will I Lose My Disk Data If I Reinstall ECS OS, Change the OS, or Change the ECS Specifications?
- How Can I Export the Original Data After I Changed My Server OS from Windows to CentOS?
- What Are the Differences Between MBR and GPT Partition Styles?
- What Does the "reserveVolume" Trace Mean in CTS?
- How Can I Download My EVS Disk Data to a Local PC?
- How Can I Upload Files to My EVS Disk?
-
Billing
- How Can I Stop Being Billed for My Disk?
- Will I Be Billed If I Have Purchased an EVS Disk But Not Used It?
- How Can I Delete or Unsubscribe from a Yearly/Monthly Disk?
- Can I Recover My Disk Data If the Disk Is Unsubscribed from, Deleted by Mistake, or Released After the Retention Period Ends?
- Will My EVS Disk Be Unsubscribed or Deleted When I Unsubscribe from or Delete Its Server?
- Will I Be Billed for the Disks in the Recycle Bin?
-
Attachment
- Why Can't I View the Attached Data Disk on the Server?
- Why Can't I Attach My Disk to a Server?
- Can I Attach a Disk to Multiple Servers?
- Can I Attach a Disk to a Server in a Different AZ?
- How Can I Add a Data Disk to an Existing Server?
- Can I Attach a Yearly/Monthly Disk to Another Server?
- Can I Attach Different Types of Disks to the Same Server?
- Can I Switch Between System Disks and Data Disks?
- What Should I Do If a Linux EVS Disk Is Attached to a Windows Server?
- Can I Attach an EVS Disk Purchased with a Yearly/Monthly Server to Another Yearly/Monthly Server?
- Can I Change the Function of a System Disk or Data Disk Purchased Along with a Server?
- How Do I Obtain My Disk Device Name in the ECS OS Using the Device Identifier Provided on the Console?
- How Can I View Data on My Disk If Its Yearly/Monthly Server Has Expired?
-
Capacity Expansion
- Can I Reduce or Temporarily Expand the Disk Capacity?
- What Are the Differences Between Expanding Capacity by Expanding an EVS Disk and Creating a New EVS Disk?
- Will My Disk Data Be Lost After I Expand the Disk Capacity?
- Can I Use Backups or Snapshots Created Before Capacity Expansion to Restore Data on Expanded Disks?
- Do I Need to Restart the Server After Expanding the Disk Capacity?
- Do I Need to Detach an EVS Disk Before Expanding Its Capacity?
- What Should I Do If My Disk Capacity Exceeds 2 TiB After Expansion?
- How Can I Allocate Newly Added Space to a New Partition?
- How Can I Allocate Newly Added Space to an Existing Partition?
- Why Did My Disk Capacity Remain Unchanged on the Server After Capacity Expansion?
- Why Can't I Expand Capacity for My Disk?
- How Do I Extend the File System of an Unpartitioned Data Disk in Linux?
- How Do I Extend the Root Partition of a Quickly Provisioned BMS?
- How Do I View the Disk Partition Style in Linux?
- Detachment
- Deletion
-
Capacity
- What Is the Maximum Capacity Supported for the System and Data Disks?
- What Should I Do If My Disk Starts to Run Out of Space?
- How Do I Clean Up My Disk Space on a Windows Server?
- What Can I Do If the Capacity of My Disk Reaches the Maximum But I Still Need More Space?
- What Should I Do If I Use fdisk to Initialize a Disk Larger Than 2 TiB and Then the Space in Excess of 2 TiB Cannot Be Displayed?
- How Can I View My Disk Usage?
- How Can I Monitor My Disk Usages?
- Can I Transfer the Data Disk Capacity to a System Disk?
- Why the Space of My New Disk Is Full After I Uploaded Only 500 MB of Files to the Disk?
-
Snapshot
- What Are the Typical Causes of a Snapshot Creation Failure?
- Does EVS Support Automatic Snapshot Creation?
- Can I Create Snapshots for Multiple Disks at a Time?
- How Is a Snapshot Created for My Disk?
- Why Can't I Roll Back My Disk Data from a Snapshot?
- Can I Roll Back Data from a Snapshot After Reinstalling the OS or Formatting a Disk?
- How Is the Snapshot Size Calculated?
- Do Snapshots Take Space on the Disk?
- Can I Perform Multiple Rollback Operations for a Snapshot?
- Can I Replicate Snapshots to Other Regions or Accounts?
- Why Can't I Find My Snapshot?
- Can I Use a Snapshot to Create a Disk and Roll Back Disk Data at Almost the Same Time?
-
Performance
- How Do I Test My Disk Performance?
- Why Does My Disk Performance Test Using Fio Have Incorrect Results?
- How Can I Handle a Slowdown in Disk Read/Write Speed or Increased I/Os?
- How Can I Improve My Disk Performance?
- Why My Disk's Read IOPS Can't Reach the Theoretical Maximum IOPS When the Disk I/O Usage Is Almost 100%?
- Sharing
- Backup
- Videos
- Glossary
-
More Documents
-
User Guide
- Overview
-
Getting Started
- Basic Operation Procedure
- Create an EVS Disk
- Attach an EVS Disk
-
Initialize an EVS Data Disk
- Introduction to Data Disk Initialization Scenarios and Partition Styles
- Initializing a Windows Data Disk (Windows Server 2008)
- Initializing a Windows Data Disk (Windows Server 2019)
- Initializing a Linux Data Disk (fdisk)
- Initializing a Linux Data Disk (parted)
- Initializing a Windows Data Disk Larger Than 2 TiB (Windows Server 2008)
- Initializing a Windows Data Disk Larger Than 2 TiB (Windows Server 2012)
- Initializing a Linux Data Disk Larger Than 2 TiB (parted)
- Permissions Management
- Disk Capacity Expansion
- Detaching an EVS Disk
- Deleting EVS Disks
- Managing Shared EVS Disks
- Managing EVS Backups
- Managing EVS Snapshots
- Managing EVS Transfers
- Managing a Tag
- Viewing EVS Monitoring Data
- Auditing
-
FAQ
-
General
- How Do I Start Using a Newly Purchased Disk?
- Can EVS Disks Be Used Directly for Storage?
- Can EVS Disks Be Used Alone?
- How Can I View My Disk Details?
- Can I Change the AZ of My Disk?
- What Are the Differences Between System Disks and Data Disks?
- How Can I Download My EVS Disk Data to a Local PC?
- How Can I Export the Original Data After I Changed My Server OS from Windows to CentOS?
- What Are the Differences Between MBR and GPT Partition Styles?
-
Capacity Expansion
- Can I Reduce or Temporarily Expand the Disk Capacity?
- What Are the Differences Between Expanding Capacity by Expanding an EVS Disk and Creating a New EVS Disk?
- Will My Disk Data Be Lost After I Expand the Disk Capacity?
- Do I Need to Restart the Server After Expanding the Disk Capacity?
- Do I Need to Detach an EVS Disk Before Expanding Its Capacity?
- What Should I Do If My Disk Capacity Exceeds 2 TiB After Expansion?
- Why Did My Disk Capacity Remain Unchanged on the Server After Capacity Expansion?
- How Do I Extend the File System of an Unpartitioned Data Disk in Linux?
-
Attachment
- Why Can't I View the Attached Data Disk on the Server?
- Can I Attach a Disk to Multiple Servers?
- Can I Attach a Disk to a Server in Another AZ?
- How Can I Add a Data Disk to an Existing Server?
- Can I Attach Different Types of Disks to the Same Server?
- What Should I Do If a Linux EVS Disk Is Attached to a Windows Server?
- Detachment
- Capacity
- Sharing
-
General
- Appendix
- Change History
-
API Reference (ME-Abu Dhabi Region)
- Before You Start
- API Overview
- Calling APIs
- Getting Started
- API Version Query
- API v2
-
OpenStack Cinder API v2
-
EVS Disk
- Creating EVS Disks
- Deleting an EVS Disk
- Updating an EVS Disk
- Querying EVS Disks
- Querying Details About All Disks
- Querying Details About a Disk
- Querying EVS Disk Types
- Querying Details About an EVS Disk Type
- Querying Details of Tenant Quotas
- Adding Metadata of an EVS Disk
- Querying Metadata of an EVS Disk
- Updating Metadata of an EVS Disk
- Querying One Piece of Metadata for an EVS Disk
- Updating One Piece of Metadata for an EVS Disk
- Deleting One Piece of Metadata for an EVS Disk
- Querying Extension APIs
- Querying All AZs
-
EVS Disk Actions
- Expanding Capacity of an EVS Disk
- Setting Bootable Flag for an EVS Disk
- Setting Read-Only Flag for an EVS Disk
- Exporting EVS Disk Data as an Image
- Attaching an EVS Disk (Deprecated)
- Detaching an EVS Disk (Deprecated)
- Reserving an EVS Disk (Deprecated)
- Canceling Reservation of an EVS Disk (Deprecated)
-
EVS Snapshot
- Creating an EVS Snapshot
- Deleting an EVS Snapshot
- Updating an EVS Snapshot
- Querying EVS Snapshots
- Querying Details About EVS Snapshots
- Querying Details About an EVS Snapshot
- Adding Metadata of an EVS Snapshot
- Querying Metadata of an EVS Snapshot
- Updating One Piece of Metadata for an EVS Snapshot
- Updating Metadata of an EVS Snapshot
- Querying One Piece of Metadata for an EVS Snapshot
- Deleting One Piece of Metadata for an EVS Snapshot
- EVS Disk Transfer
-
EVS Disk
- Out-of-Date APIs
- Appendix
- Change History
-
User Guide (Paris Region)
- Overview
-
Getting Started
- Process Overview
- Create an EVS Disk
- Attach an EVS Disk
-
Initialize an EVS Data Disk
- Introduction to Data Disk Initialization Scenarios and Partition Styles
- Initializing a Windows Data Disk (Windows Server 2008)
- Initializing a Windows Data Disk (Windows Server 2019)
- Initializing a Linux Data Disk (fdisk)
- Initializing a Linux Data Disk (parted)
- Initializing a Windows Data Disk Larger Than 2 TiB (Windows Server 2008)
- Initializing a Windows Data Disk Larger Than 2 TiB (Windows Server 2012)
- Initializing a Linux Data Disk Larger Than 2 TiB (parted)
- Permissions Management
- Creating and Using an EVS Disk
- Disk Capacity Expansion
- Detaching an EVS Disk
- Attaching an Existing Disk
- Deleting EVS Disks
- Viewing EVS Disk Details
- Managing Encrypted EVS Disks
- Managing Shared EVS Disks
- Managing EVS Backups
- Managing a Tag
- Changing EVS Disk Name
- Viewing EVS Monitoring Data
- Viewing EVS Monitoring Data (Agent Installed and Simplified Monitoring Metrics Used)
- Auditing
- Managing Quotas
-
FAQ
- Summary
-
General
- How Do I Start Using a Newly Created Disk?
- Can EVS Disks Be Used Directly for Storage?
- Can EVS Disks Be Used Alone?
- How Can I View My Disk Details?
- Can I Change the AZ of My Disk?
- Can I Change the Disk Type, Device Type, or Sharing Attribute of My Disk?
- What Should I Do If an Error Occurs on My EVS Disk?
- How Can I Obtain ECS NIC Information?
- Why Do Some of My EVS Disks Not Have WWN Information?
- How Can I Migrate Data from an EVS Disk?
- What Are the Differences Between System Disks and Data Disks?
- Will I Lose My Disk Data If I Reinstall ECS OS, Change the OS, or Change the ECS Specifications?
- How Can I Download My EVS Disk Data to a Local PC?
- How Can I Export the Original Data After I Changed My Server OS from Windows to CentOS?
- What Are the Differences Between MBR and GPT Partition Styles?
- What Does the "reserveVolume" Trace Mean in CTS?
- How Can I Upload Files to My EVS Disk?
- Billing
-
Capacity Expansion
- Can I Reduce or Temporarily Expand the Disk Capacity?
- What Are the Differences Between Expanding Capacity by Expanding an EVS Disk and Creating a New EVS Disk?
- Will My Disk Data Be Lost After I Expand the Disk Capacity?
- Can I Use Backups Created Before Capacity Expansion to Restore Data on Expanded Disks?
- Do I Need to Restart the Server After Expanding the Disk Capacity?
- Do I Need to Detach an EVS Disk Before Expanding Its Capacity?
- What Should I Do If My Disk Capacity Exceeds 2 TiB After Expansion?
- How Can I Allocate Newly Added Space to a New Partition?
- How Can I Allocate Newly Added Space to an Existing Partition?
- Why Did My Disk Capacity Remain Unchanged on the Server After Capacity Expansion?
- Why Can't I Expand Capacity for My Disk?
- How Do I Extend the File System of an Unpartitioned Data Disk in Linux?
- How Do I Extend the Root Partition of a Quickly Provisioned BMS?
- How Do I View the Disk Partition Style in Linux?
-
Attachment
- Why Can't I View the Attached Data Disk on the Server?
- Why Can't I Attach My Disk to a Server?
- Can I Attach a Disk to Multiple Servers?
- Can I Attach a Disk to a Server in Another AZ?
- How Can I Add a Data Disk to an Existing Server?
- Can I Attach Different Types of Disks to the Same Server?
- What Should I Do If a Linux EVS Disk Is Attached to a Windows Server?
- Can I Change the Function of a System Disk or Data Disk Created Along with a Server?
- How Do I Obtain My Disk Device Name in the ECS OS Using the Device Identifier Provided on the Console?
- Detachment
- Deletion
-
Capacity
- What Is the Maximum Capacity Supported for the System and Data Disks?
- What Should I Do If My Disk Starts to Run Out of Space?
- What Can I Do If the Capacity of My Disk Reaches the Maximum But I Still Need More Space?
- What Should I Do If I Use fdisk to Initialize a Disk Larger Than 2 TiB and Then the Space in Excess of 2 TiB Cannot Be Displayed?
- How Can I View My Disk Usage?
- How Can I Monitor My Disk Usages?
- Can I Transfer the Data Disk Capacity to a System Disk?
- Why the Space of My New Disk Is Full After I Uploaded Only 500 MB of Files to the Disk?
-
Performance
- How Can I Test My Disk Performance?
- Why Does My Disk Performance Test Using Fio Have Incorrect Results?
- How Can I Handle a Slowdown in Disk Read/Write Speed and Increased I/O?
- How Can I Improve My Disk Performance?
- Why My Disk's Read IOPS Can't Reach the Theoretical Maximum IOPS When the Disk I/O Usage Is Almost 100%?
- Sharing
- Backup
- Appendix
- Change History
-
API Reference (Paris Region)
- Before You Start
- API Overview
- Calling APIs
- Getting Started
-
APIs
- Disk Management
-
Tag Management
- Batch Deleting Tags of a Specified EVS Disk
- Batch Adding Tags for the Specified EVS Disk
- Obtaining All Tags of an EVS Resource Type
- Querying Tags of an EVS Disk
- Querying Details of EVS Disks by Tag
- Deleting the Tag of an EVS Resource by Key
- Querying the Number of EVS Disks by Tag
- Adding or Updating Tags for an EVS Resource (Deprecated)
- Batch Deleting Tags for an EVS Resource (Deprecated)
- Obtaining Tags of a Specified EVS Resource (Deprecated)
- Querying Tags of an EVS Resource by Key (Deprecated)
- Resetting Tags of an EVS Resource (Deprecated)
- Updating Tags of an EVS Resource by Key (Deprecated)
- Querying EVS Resources by Tag (Deprecated)
- Task Management
- EVS Replication Pair (Deprecated)
-
Replication Consistency Group (Deprecated)
- Creating a Replication Consistency Group (Deprecated)
- Deleting a Replication Consistency Group (Deprecated)
- Querying All Replication Consistency Groups (Deprecated)
- Querying Details About a Replication Consistency Group (Deprecated)
- Updating a Replication Consistency Group (Deprecated)
- Performing a Failover for a Replication Consistency Group (Deprecated)
- Synchronizing a Replication Consistency Group (Deprecated)
- Performing a Primary/Secondary Switchover for a Replication Consistency Group (Deprecated)
- Pausing a Replication Consistency Group (Deprecated)
- Reprotecting a Replication Consistency Group (Deprecated)
- Expanding EVS Disks in a Replication Consistency Group (Deprecated)
- EVS Replication Quota (Deprecated)
-
OpenStack Cinder APIs
-
Disk Management
- Creating EVS Disks
- Deleting an EVS Disk
- Updating an EVS Disk
- Querying EVS Disk Types
- Querying EVS Disks
- Querying Details About All Disks
- Querying Details About a Disk
- Querying Details About an EVS Disk Type
- Querying Extension APIs
- Expanding Capacity of an EVS Disk
- Setting Bootable Flag for an EVS Disk
- Setting Read-Only Flag for an EVS Disk
- Exporting EVS Disk Data as an Image
- Attaching an EVS Disk (Deprecated)
- Detaching an EVS Disk (Deprecated)
- Reserving an EVS Disk (Deprecated)
- Canceling Reservation of an EVS Disk (Deprecated)
- Quota Management
- AZ Query
- Disk Metadata Management
- API Version Query
-
Disk Management
-
Out-of-Date APIs
-
OpenStack Cinder API
-
EVS Disk
- Creating EVS Disks
- Deleting an EVS Disk
- Updating an EVS Disk
- Querying EVS Disks
- Querying Details About All Disks
- Querying Details About a Disk
- Querying EVS Disk Types
- Querying Details About an EVS Disk Type
- Querying Details of Tenant Quotas
- Adding Metadata of an EVS Disk
- Querying Metadata of an EVS Disk
- Updating Metadata of an EVS Disk
- Querying One Piece of Metadata for an EVS Disk
- Updating One Piece of Metadata for an EVS Disk
- Deleting One Piece of Metadata for an EVS Disk
- Querying Extension APIs
- Querying All AZs
- Querying Summary Information of EVS Disks
- Querying Details About a Disk (Deprecated)
- EVS Disk Actions
-
EVS Snapshot
- Creating an EVS Snapshot
- Deleting an EVS Snapshot
- Updating an EVS Snapshot
- Querying EVS Snapshots
- Querying Details About EVS Snapshots
- Querying Details About an EVS Snapshot
- Adding Metadata of an EVS Snapshot
- Querying Metadata of an EVS Snapshot
- Updating One Piece of Metadata for an EVS Snapshot
- Updating Metadata of an EVS Snapshot
- Querying One Piece of Metadata for an EVS Snapshot
- Deleting One Piece of Metadata for an EVS Snapshot
- EVS Disk Transfer
-
EVS Disk
-
OpenStack Cinder API
- Appendix
- Change History
-
User Guide (Kuala Lumpur Region)
- Overview
-
Getting Started
- Process Overview
- Create an EVS Disk
- Attach an EVS Disk
-
Initialize an EVS Data Disk
- Introduction to Data Disk Initialization Scenarios and Partition Styles
- Initializing a Windows Data Disk (Windows Server 2008)
- Initializing a Windows Data Disk (Windows Server 2019)
- Initializing a Linux Data Disk (fdisk)
- Initializing a Linux Data Disk (parted)
- Initializing a Windows Data Disk Larger Than 2 TiB (Windows Server 2008)
- Initializing a Windows Data Disk Larger Than 2 TiB (Windows Server 2012)
- Initializing a Linux Data Disk Larger Than 2 TiB (parted)
- Permissions Management
- Creating and Using an EVS Disk
- Disk Capacity Expansion
- Detaching an EVS Disk
- Attaching an Existing Disk
- Deleting EVS Disks
- Viewing EVS Disk Details
- Managing Encrypted EVS Disks
- Managing Shared EVS Disks
- Managing EVS Backups
- Managing EVS Snapshots
- Managing EVS Transfers
- Managing a Tag
- Changing EVS Disk Name
- Viewing EVS Monitoring Data
- Viewing EVS Monitoring Data (Agent Installed and Simplified Monitoring Metrics Used)
- Auditing
- Managing Quotas
-
FAQ
- Summary
-
General
- How Do I Start Using a Newly Created Disk?
- Can EVS Disks Be Used Directly for Storage?
- Can EVS Disks Be Used Alone?
- How Can I View My Disk Details?
- Can I Change the AZ of My Disk?
- Can I Change the Disk Type, Device Type, or Sharing Attribute of My Disk?
- What Should I Do If an Error Occurs on My EVS Disk?
- How Can I Obtain ECS NIC Information?
- Why Do Some of My EVS Disks Not Have WWN Information?
- How Can I Migrate Data from an EVS Disk?
- What Are the Differences Between System Disks and Data Disks?
- How Can I Download My EVS Disk Data to a Local PC?
- How Can I Export the Original Data After I Changed My Server OS from Windows to CentOS?
- What Are the Differences Between MBR and GPT Partition Styles?
- What Does the "reserveVolume" Trace Mean in CTS?
- How Can I Upload Files to My EVS Disk?
-
Capacity Expansion
- Can I Reduce or Temporarily Expand the Disk Capacity?
- What Are the Differences Between Expanding Capacity by Expanding an EVS Disk and Creating a New EVS Disk?
- Will My Disk Data Be Lost After I Expand the Disk Capacity?
- Can I Use Backups or Snapshots Created Before Capacity Expansion to Restore Data on Expanded Disks?
- Do I Need to Restart the Server After Expanding the Disk Capacity?
- Do I Need to Detach an EVS Disk Before Expanding Its Capacity?
- What Should I Do If My Disk Capacity Exceeds 2 TiB After Expansion?
- How Can I Allocate Newly Added Space to a New Partition?
- How Can I Allocate Newly Added Space to an Existing Partition?
- Why Did My Disk Capacity Remain Unchanged on the Server After Capacity Expansion?
- Why Can't I Expand Capacity for My Disk?
- How Do I Extend the File System of an Unpartitioned Data Disk in Linux?
- How Do I Extend the Root Partition of a Quickly Provisioned BMS?
- How Do I View the Disk Partition Style in Linux?
-
Attachment
- Why Can't I View the Attached Data Disk on the Server?
- Why Can't I Attach My Disk to a ?
- Can I Attach a Disk to Multiple Servers?
- Can I Attach a Disk to a Server in Another AZ?
- How Can I Add a Data Disk to an Existing Server?
- Can I Attach Different Types of Disks to the Same Server?
- What Should I Do If a Linux EVS Disk Is Attached to a Windows Server?
- Can I Change the Function of a System Disk or Data Disk Created Along with a Server?
- How Do I Obtain My Disk Device Name in the ECS OS Using the Device Identifier Provided on the Console?
- Detachment
- Deletion
-
Capacity
- What Is the Maximum Capacity Supported for the System and Data Disks?
- What Should I Do If My Disk Starts to Run Out of Space?
- What Can I Do If the Capacity of My Disk Reaches the Maximum But I Still Need More Space?
- What Should I Do If I Use fdisk to Initialize a Disk Larger Than 2 TiB and Then the Space in Excess of 2 TiB Cannot Be Displayed?
- How Can I View My Disk Usage?
- How Can I Monitor My Disk Usages?
- Can I Transfer the Data Disk Capacity to a System Disk?
- Why the Space of My New Disk Is Full After I Uploaded Only 500 MB of Files to the Disk?
- Performance
- Sharing
-
Snapshot
- What Are the Typical Causes of a Snapshot Creation Failure?
- Does EVS Support Automatic Snapshot Creation?
- Can I Create Snapshots for Multiple Disks at a Time?
- How Is a Snapshot Created for My Disk?
- Why Can't I Roll Back My Disk Data from a Snapshot?
- Can I Roll Back the Data from a Snapshot After Reinstalling the OS or Formatting the Disk?
- How Is the Snapshot Size Calculated?
- Do Snapshots Take Space on the Disk?
- Can I Perform Multiple Rollback Operations for a Snapshot?
- Can I Replicate Snapshots to Other Regions or Accounts?
- Why Can't I Find My Snapshot?
- Can I Use a Snapshot to Create a Disk and Roll Back the Snapshot at Almost the Same Time?
- Backup
- Appendix
- Change History
-
API Reference (Kuala Lumpur Region)
- Before You Start
- API Overview
- Calling APIs
- Getting Started
- API Version Query
- APIs
-
OpenStack Cinder APIs
-
EVS Disk
- Creating EVS Disks
- Deleting an EVS Disk
- Updating an EVS Disk
- Querying EVS Disks
- Querying Details About All Disks
- Querying Details About a Disk
- Querying EVS Disk Types
- Querying Details About an EVS Disk Type
- Querying Details of Tenant Quotas
- Adding the Metadata for an EVS Disk
- Querying Metadata of an EVS Disk
- Updating the Metadata of an EVS Disk
- Querying One Piece of Metadata for an EVS Disk
- Updating One Piece of Metadata for an EVS Disk
- Deleting One Piece of Metadata for an EVS Disk
- Querying Extension APIs
- Querying All AZs
-
EVS Disk Actions
- Expanding Capacity of an EVS Disk
- Setting Bootable Flag for an EVS Disk
- Setting Read-Only Flag for an EVS Disk
- Exporting EVS Disk Data as an Image
- Attaching an EVS Disk (Deprecated)
- Detaching an EVS Disk (Deprecated)
- Reserving an EVS Disk (Deprecated)
- Canceling Reservation of an EVS Disk (Deprecated)
-
EVS Snapshot
- Creating an EVS Snapshot
- Deleting an EVS Snapshot
- Updating an EVS Snapshot
- Querying EVS Snapshots
- Querying Details About EVS Snapshots
- Querying Details About an EVS Snapshot
- Adding Metadata of an EVS Snapshot
- Querying Metadata of an EVS Snapshot
- Updating One Piece of Metadata for an EVS Snapshot
- Updating the Metadata of an EVS Snapshot
- Querying One Piece of Metadata for an EVS Snapshot
- Deleting One Piece of Metadata for an EVS Snapshot
- EVS Disk Transfer
-
EVS Disk
- Out-of-Date APIs
- Permissions Policies and Supported Actions
- Appendix
- Change History
-
User Guide (Ankara Region)
- Overview
-
Getting Started
- Process Overview
- Create an EVS Disk
- Attach an EVS Disk
-
Initialize an EVS Data Disk
- Introduction to Data Disk Initialization Scenarios and Partition Styles
- Initializing a Windows Data Disk (Windows Server 2008)
- Initializing a Windows Data Disk (Windows Server 2019)
- Initializing a Linux Data Disk (fdisk)
- Initializing a Linux Data Disk (parted)
- Initializing a Windows Data Disk Larger Than 2 TiB (Windows Server 2008)
- Initializing a Windows Data Disk Larger Than 2 TiB (Windows Server 2012)
- Initializing a Linux Data Disk Larger Than 2 TiB (parted)
- Disk Capacity Expansion
- Detaching an EVS Disk
- Deleting EVS Disks
- Permissions Management
- Managing Shared EVS Disks
- Managing EVS Backups
- Managing EVS Snapshots
- Managing EVS Transfers
- Viewing EVS Monitoring Data
- Managing Quotas
-
FAQ
-
General
- How Do I Start Using a Newly Disk?
- Can EVS Disks Be Used Directly for Storage?
- Can EVS Disks Be Used Alone?
- How Can I View My Disk Details?
- Can I Change the AZ of My Disk?
- What Are the Differences Between System Disks and Data Disks?
- How Can I Download My EVS Disk Data to a Local PC?
- How Can I Export the Original Data After I Changed My Server OS from Windows to CentOS?
- What Are the Differences Between MBR and GPT Partition Styles?
-
Attachment
- Why Can't I View the Attached Data Disk on the Server?
- Can I Attach a Disk to Multiple Servers?
- Can I Attach a Disk to a Server in Another AZ?
- How Can I Add a Data Disk to an Existing Server?
- Can I Attach Different Types of Disks to the Same Server?
- What Should I Do If a Linux EVS Disk Is Attached to a Windows Server?
- How Do I Obtain My Disk Device Name in the ECS OS Using the Device Identifier Provided on the Console?
-
Capacity Expansion
- Can I Reduce or Temporarily Expand the Disk Capacity?
- What Are the Differences Between Expanding Capacity by Expanding an EVS Disk and Creating a New EVS Disk?
- Will My Disk Data Be Lost After I Expand the Disk Capacity?
- Do I Need to Restart the Server After Expanding the Disk Capacity?
- Do I Need to Detach an EVS Disk Before Expanding Its Capacity?
- What Should I Do If My Disk Capacity Exceeds 2 TiB After Expansion?
- Why Did My Disk Capacity Remain Unchanged on the Server After Capacity Expansion?
- How Do I Extend the File System of an Unpartitioned Data Disk in Linux?
- How Do I View the Disk Partition Style in Linux?
- Detachment
-
Capacity
- What Is the Maximum Capacity Supported for the System and Data Disks?
- What Should I Do If My Disk Starts to Run Out of Space?
- What Should I Do If I Use fdisk to Initialize a Disk Larger Than 2 TiB and Then the Space in Excess of 2 TiB Cannot Be Displayed?
- How Can I View My Disk Usage?
- Why the Space of My New Disk Is Full After I Uploaded Only 500 MB of Files to the Disk?
-
Snapshot
- What Are the Typical Causes of a Snapshot Creation Failure?
- Does EVS Support Automatic Snapshot Creation?
- Can I Create Snapshots for Multiple Disks at a Time?
- How Is a Snapshot Created for My Disk?
- Why Can't I Roll Back My Disk Data from a Snapshot?
- Can I Roll Back the Data from a Snapshot After Reinstalling the OS or Formatting the Disk?
- How Is the Snapshot Size Calculated?
- Do Snapshots Take Space on the Disk?
- Can I Perform Multiple Rollback Operations for a Snapshot?
- Can I Replicate Snapshots to Other Regions or Accounts?
- Why Can't I Find My Snapshot?
- Can I Use a Snapshot to Create a Disk and Roll Back the Snapshot at Almost the Same Time?
- Sharing
-
General
- Appendix
- Change History
-
API Reference (Ankara Region)
- Before You Start
- API Overview
- Calling APIs
- Getting Started
- APIs
-
OpenStack Cinder APIs
-
Disk Management
- Creating EVS Disks
- Deleting an EVS Disk
- Updating an EVS Disk
- Querying EVS Disk Types
- Querying EVS Disks
- Querying Details About All Disks
- Querying Details About a Disk
- Querying Details About an EVS Disk Type
- Querying Extension APIs
- Expanding Capacity of an EVS Disk
- Setting Bootable Flag for an EVS Disk
- Setting Read-Only Flag for an EVS Disk
- Exporting EVS Disk Data as an Image
- Attaching an EVS Disk (Deprecated)
- Detaching an EVS Disk (Deprecated)
- Reserving an EVS Disk (Deprecated)
- Canceling Reservation of an EVS Disk (Deprecated)
- Quota Management
- AZ Query
- Disk Transfer Management
- Disk Metadata Management
- API Version Query
-
Disk Management
-
Out-of-Date APIs
- API
-
OpenStack Cinder API
-
EVS Disk
- Creating EVS Disks
- Deleting an EVS Disk
- Updating an EVS Disk
- Querying EVS Disks
- Querying Details About All Disks
- Querying Details About a Disk
- Querying EVS Disk Types
- Querying Details About an EVS Disk Type
- Querying Details of Tenant Quotas
- Adding Metadata of an EVS Disk
- Querying Metadata of an EVS Disk
- Updating Metadata of an EVS Disk
- Querying One Piece of Metadata for an EVS Disk
- Updating One Piece of Metadata for an EVS Disk
- Deleting One Piece of Metadata for an EVS Disk
- Querying Extension APIs
- Querying All AZs
- Querying Summary Information of EVS Disks
- Querying Details About a Disk (Deprecated)
- EVS Disk Actions
-
EVS Snapshot
- Creating an EVS Snapshot
- Deleting an EVS Snapshot
- Updating an EVS Snapshot
- Querying EVS Snapshots
- Querying Details About EVS Snapshots
- Querying Details About an EVS Snapshot
- Adding Metadata of an EVS Snapshot
- Querying Metadata of an EVS Snapshot
- Updating One Piece of Metadata for an EVS Snapshot
- Updating Metadata of an EVS Snapshot
- Querying One Piece of Metadata for an EVS Snapshot
- Deleting One Piece of Metadata for an EVS Snapshot
- EVS Disk Transfer
-
EVS Disk
- Appendix
- Change History
-
User Guide
- General Reference
Copied.
Disk Snapshot
What Is EVS Disk Snapshot?
A snapshot is a complete copy or image of the disk data taken at a specific time. Snapshot is a major DR approach, and you can use a snapshot to restore disk data to the time when the snapshot was created. You can create snapshots for disks on the console or via the API.
EVS disk snapshots are sometimes referred to as snapshots in this document.
You can create snapshots to rapidly save the disk data at specified time points. In addition, you can use snapshots to create new disks so that the created disks will contain the snapshot data in the beginning.
Legacy Snapshot Principles
- Disk v1 is created, which contains no data.
- Data d1 and d2 are written to disk v1. Data d1 and d2 are written to new spaces.
- Snapshot s1 is created for disk v1 modified in step 2. Data d1 and d2 are not saved as another copy elsewhere. Instead, a relationship between snapshot s1 and data d1 and d2 is established.
- Data d3 is written to disk v1, and data d2 is changed to d4. Data d3 and d4 are written to new spaces, and data d2 is not overwritten. The relationship between snapshot s1 and data d1 and d2 is still valid. Snapshot s1 can be used to restore data if needed.
- Snapshot s2 is created for disk v1 modified in step 4, and a relationship between snapshot s2 and data d1, d3, and d4 is established.
Figure 1 Snapshot Principles
Standard Snapshot Principles
Standard snapshots back up data by data block. They include full snapshots and incremental snapshots. The first snapshot created for an EVS disk is a full snapshot, which backs up all data blocks on the disk at the time of the snapshot. Subsequent snapshots are incremental snapshots, which back up only changed data blocks since the last snapshot.
Metadata files of full and incremental snapshots record information about all data blocks when the snapshots were created. So, you can use any snapshot to restore your disk data to the state when the snapshot was created.

Based on the source of data blocks, a snapshot's metadata file contains information about three types of data blocks: inherited data blocks (inherited from the last snapshot), modified data blocks (have modifications compared with the last snapshot), and new data blocks (new compared with the last snapshot).
A snapshot's data file stores only the changed data blocks (modified and new data blocks) compared with the last snapshot.
Let's use the preceding figure for illustration. Assume that data is written to an EVS disk at 09:30 and 10:30. Snapshot 1 is created at 09:00, snapshot 2 is created at 10:00, and snapshot 3 is created at 11:00.
- At 09:00, snapshot 1 is created for the disk. This is the first time that a snapshot is created for this disk, so snapshot 1 is a full snapshot and it contains all the data on the disk, including data blocks A, B, and C. The metadata file of snapshot 1 records information about the disk's full data blocks: A, B, and C.
- After snapshot 1 is created, data block A is changed to A1, data block B is changed to B1, and data block D is added. Then, snapshot 2 is created at 10:00. It is an incremental snapshot. Compared with snapshot 1, data blocks A1, B1, and D are changed data blocks. The metadata file of snapshot 2 records information about the disk's full data blocks: A1, B1, C, and D, among which data block C is inherited from snapshot 1.
- After snapshot 2 is created, data block A1 is changed to A2, data block C is changed to C1, and data block E is added. Then, snapshot 3 is created at 11:00. It is an incremental snapshot. Compared with snapshot 2, data blocks A2, C1, and E are changed data blocks. The metadata file of snapshot 3 records information about the disk's full data blocks: A2, B1, C1, D, and E, among which data blocks B1 and D are inherited from snapshot 2.
Calculating the Standard Snapshot Storage Usage
The total snapshot storage usage of an EVS disk is calculated by snapshot chain. A snapshot chain collects the storage space used by data blocks of all the snapshots of a disk.
- Snapshot chain's storage usage calculation after snapshots are added
Take the scenario in Figure 3 as an example. Assume that the size of a snapshot's data block is fixed at 2 MiB. The snapshot chain's storage usage is calculated as follows:
- After snapshot 1 is created, the snapshot chain of the disk contains only one snapshot. Snapshot chain's storage usage = Snapshot 1's storage usage = Size of data block A + Size of data block B + Size of data block C = 6 MiB
- After snapshot 2 is created, the snapshot chain of the disk contains two snapshots: snapshot 1 and snapshot 2. Snapshot chain's storage usage = Snapshot 1's storage usage + Snapshot 2' storage usage = 6 MiB + (Size of data block A1 + Size of data block B1 + Size of data block D) = 12 MiB
- After snapshot 3 is created, the snapshot chain of the disk contains three snapshots: snapshot 1, snapshot 2, and snapshot 3. Snapshot chain's storage usage = Snapshot 1's storage usage + Snapshot 2' storage usage + Snapshot 3's storage usage = 6 MiB + 6 MiB + (Size of data block A2 + Size of data block C1 + Size of data block E) = 18 MiB
- Snapshot chain's storage usage calculation after snapshots are deleted
When a snapshot is deleted, all data block information in this snapshot's metadata file is traversed, and the following deletion rules are applied:
- If a data block is inherited by the next snapshot, it will not be deleted.
- If a data block is not inherited by the next snapshot:
- For an inherited data block, if the previous snapshot that the data block is inherited from is not deleted, the data block will not be deleted. Otherwise, it will be deleted.
- For a modified data block, it will be deleted.
- For a new data block, it will be deleted.
Figure 4 Snapshot data block deletion rulesThe following example describes how to calculate a snapshot chain's storage usage after snapshots are deleted.
Take the scenario in Figure 5 as an example. Assume that snapshot 2 is deleted at 14:00 and snapshot 3 is deleted at 15:00. The snapshot chain's storage usage is calculated as follows:
- Before any snapshot is deleted, the snapshot chain's storage usage is 18 MiB (Snapshot 1's storage usage + Snapshot 2's storage usage + Snapshot 3's storage usage).
- When snapshot 2 is deleted at 14:00, information about all data blocks in the metadata file of snapshot 2 is traversed.
- Data block A1: It is not inherited by snapshot 3 and is modified from data block A of snapshot 1. So, data block A1 will be deleted.
- Data block B1: It is inherited by snapshot 3, so it will not be deleted.
- Data block C: It is not inherited by snapshot 3, but is inherited from snapshot 1 and snapshot 1 is not deleted. So, data block C will not be deleted.
- Data block D: It is inherited by snapshot 3. So, it will not be deleted.
After snapshot 2 is deleted, the snapshot chain's storage usage is 16 MiB (18 MiB – Size of data block A1).
- When snapshot 3 is deleted at 15:00, information about all data blocks in the metadata file of snapshot 3 is traversed.
- Data block A2: It is not inherited by the next snapshot and is modified from data block A1 of snapshot 2. So, data block A2 will be deleted.
- Data block B1: It is not inherited by the next snapshot, but is inherited from snapshot 2 and snapshot 2 has been deleted. So, data block B1 will be deleted.
- Data block C1: It is not inherited by the next snapshot and is modified from data block C of snapshot 2. So, data block C1 will be deleted.
- Data block D: It is not inherited by the next snapshot, but is inherited from snapshot 2 and snapshot 2 has been deleted. So, data block D will be deleted.
- Data block E: It is not inherited by the next snapshot and is newly added in snapshot 3. So, data block E will be deleted.
After snapshot 3 is deleted, the snapshot chain's storage usage is 6 MiB (16 MiB – Size of data block A2 – Size of data block B1 – Size of data block C1 – Size of data block D – Size of data block E).
Feedback
Was this page helpful?
Provide feedbackThank you very much for your feedback. We will continue working to improve the documentation.See the reply and handling status in My Cloud VOC.
For any further questions, feel free to contact us through the chatbot.
Chatbot