Shulou(Shulou.com)06/02 Report--

Editor to share with you the scope and meaning of commercial users of snapshots, I believe that most people do not know much about it, so share this article for your reference, I hope you will learn a lot after reading this article. Let's learn about it!

Snapshot commercial FAQ

Commercialization time is related to scope

What is snapshot commercialization?

Snapshot service, as a means of data backup when customers use ECS instances, has been in the stage of free public testing since 2011.

In order to provide a better ECS snapshot service experience and optimize the cost of snapshot data storage, we plan to adjust the official charging time for the commercialization of snapshots, as shown below:

The official charging time has been postponed from June 1, 2017 to 10:00 on July 3, 2017, and will continue to be free of charge for snapshot service storage from now until 10:00 on July 3, 2017. however, you can still view snapshot bill details in the fee center.

Aliyun plans to adjust the charging standards and service flow of ECS snapshots. For more information, please see: Ariyun ECS Snapshot Service Price Adjustment announcement on July 3, 2017.

Transitional discount period after snapshot commercialization?

Considering that snapshot service has become a means of data backup for many users on ECS, in order to reduce the possible impact of commercial switching on you, the snapshot service price discount period is held from March 28 to July 3, 2017 at 10:00, during this period:

You are free of charge for the snapshot service, but you will still see the bill for the snapshot service in the expense center > consumption details.

What is the user range of snapshot commercialization?

The commercialization of the snapshot service only includes users of Aliyun's official website in China. Users using ECS CVM, such as International Station or Japan Station, will be notified of the time of commercialization, and the snapshot service they are using will not be affected.

Related to OSS prepaid storage package

If I have already activated OSS, will the snapshot be automatically saved to my OSS Bucket? Do you need to create another Bucket to store snapshots?

It is not automatically saved to an existing OSS Bucket. The location where the snapshot is stored is independent of your self-built OSS Bucket, and you do not need to create a new Bucket for the snapshot.

If you have purchased an OSS prepaid storage package and are using snapshot and OSS services at the same time, which product will be deducted first?

The current storage package deduction order is based on the product billing time, so there is no rule of priority deduction.

After the snapshot is commercialized, I want to continue to use it. Which product do I need to buy, cloud disk or object storage OSS resource pack?

If you have previously activated the snapshot service in the ECS console, you do not need to activate it again or purchase additional products or activate other products. You can continue to create snapshots manually or use automatic snapshots.

The default is pay-per-view. You can also choose to purchase prepaid storage packages to optimize snapshot usage costs. The current snapshot products reuse object storage OSS storage packages. You can optimize snapshot usage costs by purchasing prepaid storage packages.

Cost correlation

What is the charging model of snapshot commercialization?

After commercialization, snapshot service will be charged according to snapshot capacity. Please refer to the details of snapshot service fee (postpaid by quantity).

How to calculate the snapshot fee?

Billing standard: snapshot fees are billed according to the storage space occupied by snapshots. If you do not purchase a prepaid storage package, the hourly fee will be deducted by default by postpaid. Hourly price = monthly price / 24 hours / 30 days. Please refer to the details of snapshot service fee (postpaid by quantity).

For example, if you currently have a snapshot capacity of 1200GiB in East China 1, the monthly cost is 1200GiB * 0.148 CNY / GiB/ monthly = 177.6 CNY under postpaid mode, and the fee for the previous hour is 177.6 CNY / 24Universe 0.2467 CNY.

If you have purchased a prepaid storage package of 1TiB in East China 1, the snapshot capacity within the 1TiB will be deducted directly from the storage package, and the capacity exceeding the 1TiB (200GiB) will be deducted on a postpaid basis. The deduction method refers to the above calculation method.

Fees in other regions can be calculated as above. Postpaid and prepaid storage packages vary in different regions. For more information, please refer to the Block Storage Product Price details page-Snapshot Price section.

After charging for snapshots, do you start charging fees if you don't stop automatic snapshots?

Right. "if you do not stop the automatic snapshot policy, the snapshot system automatically generates snapshots according to the snapshot time points you set previously, and retains these automatic snapshots according to the length of time you set previously."

Snapshots are billed according to the actual storage capacity occupied, so there is a snapshot fee. The default is pay-per-view, and you can also choose to purchase prepaid storage packages to optimize snapshot usage costs.

How to charge for traffic that exceeds prepaid storage packages?

Suppose you have bought a 100-gigabyte prepaid storage package and currently have 5 snapshots, each of which is 20GiB, and you have purchased a 100GiB prepaid storage package. When the total snapshot capacity does not exceed 100GiB, the snapshot capacity will be deducted from the storage package. Snapshot capacity exceeding 100GiB will be billed on a postpaid basis.

There will be a charge for snapshots. Will the previous snapshots be deleted?

Snapshots that have been backed up before are billed according to the actual storage capacity occupied, resulting in snapshot fees. The default is pay-per-view, and you can also choose to purchase prepaid storage packages to optimize snapshot usage costs. If you no longer need to use these snapshots, you can choose to delete them before the official charge.

If you don't want to pay, can the previous snapshot continue to be used?

"Yes, but there is a charge based on the actual storage capacity consumed by the snapshot." Snapshots are charged according to the storage capacity actually occupied, starting from 10:00 on July 3, 2017.

If you do not want to pay, it is recommended that you back up the data in the snapshot by creating a disk with the snapshot before the formal charge, and then delete all snapshots to avoid unnecessary fees.

After the snapshot is charged, will both manual and automatic snapshots created before be charged?

Right. Manual snapshots and automatic snapshots are only two ways to create snapshots, and snapshots created are billed according to the actual storage capacity consumed, resulting in snapshot fees.

Stop the snapshot policy before charging for snapshots. Do you need to delete historical snapshots manually? Will my history snapshot be deleted directly after the official charge?

If you do not want to pay for snapshots, you need to delete the automatic snapshot policy and delete historical snapshots manually before the formal charge.

After snapshots are charged, undeleted historical snapshots are charged according to the actual storage capacity occupied. If the account is in arrears, the historical snapshot will be deleted after 15 days of arrears.

After the snapshot is charged, what is the impact of account arrears on the snapshot?

Once the account is in arrears, the snapshot service will be stopped after 24 hours of arrears. From the date of arrears, snapshots are retained for 15 days; after 15 days, all snapshots are released.

If the account is in arrears, will the snapshot of the connection relationship (created disk or mirror) be deleted after 15 days of arrears?

No, I won't.

What is the relationship between snapshot service and block storage service in terms of charging?

Snapshot service and block storage are billed separately, and there is no billing association between them. The bills between the two are also separate.

Functional capacity correlation

How is the snapshot capacity calculated and is it equal to the disk size?

The capacity of a single snapshot is less than the disk capacity.

A snapshot is a capture of the entire disk data state at some point in time. In the process of creating a snapshot, the capacity of a single snapshot is less than the disk capacity by eliminating empty blocks. Ali Cloud will identify disk space that has never been written to data, mark it as empty blocks, and do not measure it, so as to save users' snapshot space. Therefore, as long as the customer has not written all the disk capacity, the capacity of a single snapshot is less than the disk capacity.

For example, a user has a 40 GiB data disk, and the actual amount of data written into the disk is 20 GiB.

The first snapshot is full, because holes are eliminated during snapshot creation, so the snapshot capacity is less than 40GiB.

The second snapshot is an incremental snapshot, and the snapshot capacity is equal to the amount of data that changes between the two snapshots.

For the specific snapshot principle, please refer to the incremental snapshot mechanism.

Accurate definition of "data write operation"

First of all, to clarify a concept, for the underlying distributed storage system, "data write operation" not only means the business data written by the user, but also includes a series of Ibig O operations such as formatting disk.

After the user gets the disk, it must be formatted before it can be used normally. The essence of formatting is the process of establishing a file system. Before a partition or disk can be used as a file system, it needs to initialize and record the data structure to the disk, a process called establishing a file system.

Therefore, establishing a file system on the disk means that there is a data write operation to the disk. Different file systems write different file sizes when formatting, as follows:

Windows system format, which is divided into fast format and normal format:

Quick formatting is simply assigning a file system to a partition and rewriting the directory table

Normal formatting not only does this, but also scans the partition sector by sector to identify and mark bad sectors.

Therefore, the normal formatting operation will fill the empty block of the disk, which is equivalent to writing the whole disk. In this case, the size of the first full snapshot is similar to the disk capacity. Fast formatting, on the other hand, takes up relatively little actual space.

Linux system formatting is also a process of establishing a file system. Therefore, for the disk that has just been formatted, when the user does not write business data, the first snapshot will also have a certain capacity, depending on the file system format.

Will deleting files in an ECS instance reduce space consumption?

The so-called deletion in the file system is just a mark on the head of the file that needs to be deleted to tell the user that the space is available and will not reduce the space occupied by the disk itself.

Why is the snapshot capacity greater than the amount of data seen in the file system?

As mentioned above, file system formatting, file deletion, and user write data behavior all reduce the number of disk empty blocks, thus weakening the effect of eliminating empty blocks during snapshot creation. As a result, you can see that the snapshot capacity is larger than the amount of data displayed in the file system. Reference for details: why the file size is inconsistent with the space occupied by snapshots.

Refer to the snapshot increment description, if the intermediate snapshot is deleted, can the subsequent snapshot be used?

"ECS snapshots support the recovery of full disk data from any snapshot, so deleting one of the snapshots does not affect the other incremental snapshots."

For example: snapshot 1 > Snapshot 2 > Snapshot 3. Every snapshot has an update on every disk. When Snapshot 2 is deleted, Snapshot 1 and Snapshot 3 can continue to be used.

Functional correlation

How to activate snapshot service?

If you have not used the snapshot service, or if you used the snapshot service through Open API, log in to the ECS Management console > Snapshot Management page, agree to the relevant terms of service and activate the snapshot service before you can use the snapshot-related features normally.

If you have enabled the snapshot service in the ECS management console, you do not need to activate the service for a second time, and you can use the snapshot service normally without being affected. Snapshots are billed according to capacity. Users choose whether to use them or not. There is no charge for not using snapshots.

What is the relationship between snapshot and mirror?

The current mirror is a product service packaged based on the snapshot, and the snapshot is bound to the mirror created by the snapshot. Therefore, if you want to delete a snapshot, you need to delete the mirror associated with it before you can delete the snapshot.

How to delete the relationship between snapshots and mirrors, snapshots, instances and mirrors while retaining associated instances and disks?

Snapshots, mirrors, disks, and instances are currently bound. Resetting the system disk initialization disk feature all depends on the binding relationship between the above. In April 2017, Aliyun decoupled the binding relationship between "mirror and instance" and "snapshot and disk".

The image used to create an instance can be deleted separately, but after deletion, it is similar to the business operation that depends on the original mirror data, such as reinitializing the disk.

Snapshots that have been used to create disks can be deleted separately. Similarly, business operations that depend on the state of the original snapshot data, such as reinitializing the disk, cannot be operated.

Used to create a snapshot of a mirror. Before deleting, you need to delete the corresponding mirror before it can be deleted.

What is the relationship between snapshots and block storage and OSS object storage?

Snapshot is the backup of data to a disk at a certain point in time. Snapshot service is an efficient and simple means of data backup for cloud disk.

Block storage (Block Storage) is block-level random storage with low latency, persistence and high reliability provided by Aliyun for CVM ECS, which is usually called disk. The system disk and data disk on CVM are block storage products.

Ali Cloud object Storage Service (Object Storage Service, referred to as OSS) is a massive, secure, low-cost and highly reliable cloud storage service provided by Aliyun. You can upload and download data from any application, anytime, anywhere by calling API, or you can simply manage the data through the Web console. OSS is suitable for storing any type of files, suitable for all kinds of websites, development enterprises and developers.

Therefore, snapshot, block storage and OSS object storage are three independent products, which are billed separately without any billing relationship, and the bills of the three products are also independent.

Currently, in order to optimize the customer experience and reduce repeat purchase costs, snapshots and OSS object storage can share OSS prepaid storage packages. Prepaid storage packages purchased in a region can be offset against both snapshot capacity and OSS object storage capacity in that region, and the resource occupancy details of snapshots and OSS object storage can be viewed in the details of resource package usage.

Can I set multiple snapshot policies for a cloud disk?

I can't. Currently, only one automatic snapshot policy can be set for a cloud disk.

After the snapshot is formally commercialized, it will continue to enrich the snapshot function to meet the actual business needs of more customers.

The above is all the contents of the method of commercializing the user scope and meaning of snapshots. Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.