Got it

HCIP-Cloud Computing | FusionCompute Disk Technologies

Latest reply: Aug 9, 2022 14:07:42 429 26 10 0 0

Hello, everyone!

In storage virtualization, user storage is presented as files. VM disks, snapshots, and VM configurations correspond to independent files. There are typical types of disk files:

  • Common

  • Thick provisioned lazy-zeroed

  • Thin provisioned

  • Differencing

Disk are classified as the following types in terms of data security:

  • Persistent

  • Non-persistent

Common Disks


The size of a common disk is the same as that of a virtual disk. The value 0 is entered for all file locations. Such disks occupy large amounts of space and have high provisioning times.

In the FusionSphere system, disks created in ordinary mode are common disks. When a common disk is created, the space required by the disk is allocated at the time of creation, and the remaining data on the physical device is zeroed out. Common disks deliver optimal performance and ensure data security. Therefore, these disks can be used to meet high I/O Operations Per Second(IOPS) requirements. However, it takes a long time to create common disks compared to other disk types.


common disks


Thick Provisioned Lazy-Zeroed Disks

The size of a thick provisioned lazy-zeroed disk is the same as that of a virtual disk. However, the value 0 is not entered. Such disks occupy relatively large amounts of space and are faster to provision than common disks.

In the FusionSphere system, disks created in thick provisioned lazy-zeroed mode are thick provisioned lazy-zeroed disks, helping improve storage utilization with faster creation times. When a disk is created in this mode, the space required for the virtual disk is allocated at the time of creation and the disk is not zeroed out during creation. The performance of disks created in thick provisioned lazy-zeroed mode is not as good as common disks. Therefore, the disks should be used to meet quick provisioning and low IOPS requirements


THICK


Thin Provisioned Disks

When a thin provisioned disk is created, size is set to 0. The thin provisioned disk contains small volumes of metadata and has a size of tens of KB. Thin provisioned disks are created in a short amount of time. As users write data, the size and occupied space of the thin provisioned disk increases.

In the FusionSphere system, disks created in thin provisioned mode are thin provisioned disks, improving storage utilization. Thin provisioning is used to save storage space. Disk space is not allocated when the disk is created but dynamically allocated when user |/O is written into disk files. Disk performance is lower than that of common disks. Therefore, thin provisioned disks should be used when users do not have specific storage requirements, or if the planned capacity is larger than the occupied capacity.


thin provisioned disks


Differencing Disks

A differencing disk is a virtual hard disk (VHD) that can be created only when a parent VHD exists. The differencing VHD stores only the differences with the parent VHD, including data added or deleted. A Differencing VHD is dependent on a parent VHD to be fully functional. If the parent VHD is modifiedd, all differencing VHDs related to it become invalid, and all data written to the differencing VHD is lost.

Differencing VHDs are used in the Fusionphere system's snapshots, non-persistent disk, and linked cloning functions, protecting the parent VHD form being modified and keeping track of modified disk blocks on VM disks.


differencing disks

When a read operation is performed on a differencing VHD, the system read data blocks in the differencing VHD first. If the required data does not exist, this data block will not be modified. The system then finds the parent VHD by the file locator in differencing VHD's header and reads data on the parent VHD. For a write operation, all data is written to the differencing VHD.

The structure of a differencing VHD is the same as that of a dynamic VHD. The header of a differencing VHD contains the pathname of the parent VHD. Modified blocks are stored in the differencing VHD, and the differencing VHD expands dynamically as data is written to it.


Persistent and Non-persistent Disks

A persistent disk stores data permanently. When an independent persistent disk is and is not contained in a snapshot, any change is immediately and created permanently written to the disk. Snapshot rollback does not roll the data back. The disks are used to store personal data such as a USB flash drive.

A non-persistent disk stores data temporarily. To protect data on a non-persistent disk, a differencing disk is created for the disk during VM startup. When the VM is running, data changes are written to the differencing disk. After the VM stops, the differencing disk is deleted to restore the non-persistent disk. Non-persistent disks are used for public computers and for restoring computer data to a previous state

That's all, thanks!

The post is synchronized to: StorageHCIP - Cloud Computing

  • x
  • convention:

Jackson.F
Created Jun 30, 2022 09:23:29

Thanks for your sharing!
View more
  • x
  • convention:

olive.zhao
olive.zhao Created Jun 30, 2022 09:23:43 (0) (0)
Thanks!  
vladislavzh
HCIE Created Jul 10, 2022 16:30:05

good post. thank you
View more
  • x
  • convention:

olive.zhao
olive.zhao Created Jul 28, 2022 01:24:04 (0) (0)
 
RachelGomez
Created Jul 11, 2022 05:02:02

HCIP-Cloud Computing Certification is a validation of an individual's skills HCIP-Cloud Computing Certification Exams Training Materials It is well known that Huawei HCIP-Cloud Computing certification training is experiencing a great demand in IT industry area.

Regards,
Rachel Gomez
View more
  • x
  • convention:

thisu
Created Jul 11, 2022 05:17:25

Good share
View more
  • x
  • convention:

olive.zhao
olive.zhao Created Jul 12, 2022 11:53:59 (0) (0)
Thanks!  
user_4794745
Created Jul 26, 2022 19:38:07

helpful
View more
  • x
  • convention:

olive.zhao
olive.zhao Created Jul 28, 2022 01:24:41 (0) (0)
Thanks!  
NTan33
Created Jul 27, 2022 01:52:58

Interesting to know.
View more
  • x
  • convention:

olive.zhao
olive.zhao Created Jul 28, 2022 01:24:51 (0) (0)
Thanks!  
user_4802799
Created Jul 28, 2022 07:20:27

nice sharing!
View more
  • x
  • convention:

wissal
MVE Created Aug 8, 2022 07:26:03

Very Interesting knowledge
View more
  • x
  • convention:

olive.zhao
olive.zhao Created Aug 9, 2022 01:31:09 (0) (0)
Thanks!  
thibay
Created Aug 8, 2022 14:36:08

Good one
View more
  • x
  • convention:

olive.zhao
olive.zhao Created Aug 9, 2022 01:30:58 (0) (0)
Thanks!  
12
Back to list

Comment

You need to log in to comment to the post Login | Register
Comment

Notice: To protect the legitimate rights and interests of you, the community, and third parties, do not release content that may bring legal risks to all parties, including but are not limited to the following:
  • Politically sensitive content
  • Content concerning pornography, gambling, and drug abuse
  • Content that may disclose or infringe upon others ' commercial secrets, intellectual properties, including trade marks, copyrights, and patents, and personal privacy
Do not share your account and password with others. All operations performed using your account will be regarded as your own actions and all consequences arising therefrom will be borne by you. For details, see " User Agreement."

My Followers

Login and enjoy all the member benefits

Login

Block
Are you sure to block this user?
Users on your blacklist cannot comment on your post,cannot mention you, cannot send you private messages.
Reminder
Please bind your phone number to obtain invitation bonus.
Information Protection Guide
Thanks for using Huawei Enterprise Support Community! We will help you learn how we collect, use, store and share your personal information and the rights you have in accordance with Privacy Policy and User Agreement.