- What's New
- Function Overview
-
Service Overview
- EVS Infographics
- What Is EVS?
- Disk Types and Performance
- Device Types and Usage Instructions
- Shared EVS Disks and Usage Instructions
- EVS Encryption
- EVS Backup
- EVS Snapshot (OBT)
- Differences Between EVS Backups and EVS Snapshots
- EVS Three-Copy Redundancy
- Billing
- Permissions
- Constraints
- EVS and Other Services
- Basic Concepts
- Change History
- 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 Snapshots (OBT)
- 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
- Using LVM to Manage EVS Disks
- Handling Insufficient Disk Space on a Windows ECS
- RAID Array Creation with EVS Disks
-
Extending Disk Partitions and File Systems (Linux Kernel Earlier Than 3.6.0)
- Preparing for Extending Disk Partitions and File Systems (Linux Kernel Earlier Than 3.6.0)
- Extending System Disk Partitions and File Systems (Linux Kernel Earlier Than 3.6.0)
- Extending Data Disk Partitions and File Systems (Linux Kernel Earlier Than 3.6.0)
- Extending SCSI Data Disk Partitions and File Systems (Linux Kernel Earlier Than 3.6.0)
-
API Reference
- 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 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
- 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
-
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 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 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?
-
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 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 Disk Data at Almost the Same Time?
- Can I Modify Data in My EVS Snapshot?
-
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
Attaching an Existing Shared Disk
Scenarios
This section describes how to attach an existing shared disk to a server to be used as a data disk.
- Disk Sharing: Enabled
- Function: Data disk
- Status: In-use or Available
Notes and Constraints
If you simply attach a shared disk to multiple servers, files cannot be shared among them. Because there are no mutually agreed data read/write rules among them, read and write operations from them may interfere with each other, or unpredictable errors may occur. To share files between the servers, set up a shared file system or a clustered management system first.
- A shared disk can be attached to a maximum of 16 servers. These servers and the shared disk must be in the same AZ of a region.
- A shared, In-use disk can only be attached to servers when the maximum number of servers that the disk can be attached to has not been reached.
- A shared disk can only be attached to servers running the same type of OS (either Windows or Linux).
For example, if you attach a shared disk to multiple Windows servers and then detach it, the shared disk cannot be attached to Linux servers later. This is because Windows and Linux support different file systems. Improper operations may damage the original file system.
- A shared disk can only be used as a data disk. It cannot be used as a system disk.
- Cloud servers created from ISO images are only used for OS installation. They have limited functions and cannot have EVS disks attached.
- A server must be in the Running or Stopped state before disks can be attached to it.
- A frozen disk cannot be attached.
- A detached system disk purchased together with a yearly/monthly server can be re-attached to be used as a data disk for any server. If you want to use it again as a system disk, you must attach it to the original server.
- A detached system disk purchasedcreated together with a pay-per-use server can be re-attached to be used as a data disk for any server. If you want to use it again as a system disk, you must attach it to a server that uses the same image as the original server.
Procedure
- Log in to the console.
- Click
in the upper left corner and choose Storage > Elastic Volume Service.
The Elastic Volume Service page is displayed.
- In the disk list, locate the disk and click Attach.
- Shared disks support batch attachment, so you can attach a shared disk to multiple servers. In the Attach Disk dialog box, the left area shows the server list. After you select the target servers, they will be displayed in the right area.
- A shared disk can only be attached to servers when the disk status is Available or In-use.
- Select servers to attach the disk. Ensure that the disk and servers are in the same AZ. After you select servers, the system automatically inputs Data disk as the disk function.
One device name can be used for one disk only. If a device name has been used, it will no longer show up in the drop-down list and cannot be selected.
Figure 1 Attach Disk - Click OK to go back to the disk list page.
The status of the disk is Attaching, indicating that the disk is being attached to the server. When the disk status changes to In-use, the disk has been attached.
- (Optional) Mount the existing disk partition on a mount point if you are attaching the disk to Linux servers. The mount command is as follows:
mount Disk partition Mount point
Helpful Links
To find out why your disk cannot be attached, see Why Can't I Attach My Disk to a Server?
To check out more attachment FAQs, see Attachment.
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