How to choose the cloud storage System

Cloud storage is an effective choice for a range of storage requirements. Understanding the key features of various cloud storage systems helps identify the right use cases and avoids potential and costly errors.

We use the term "cloud storage" as if there is a single data storage service. There are actually many types of cloud storage systems. These systems can be categorized by identifying the characteristics of the appropriate use cases. For example, you don't want to run an inventory management system using a filing system that takes hours to respond to a read request. Similarly, there is no reason to pay for low latency SSD storage when disk-based storage is effective.

ROM list types of cloud storage systems

For ease of review, we classify the storage system according to four common technical features:

1. Reliability

2. Accessibility

3. File vs. Object storage

4. Size limit

While these are major features, these are not the only factors you may have to consider when choosing a cloud storage System. There are also features that focus on the business, such as cost and latency, which should be taken into account. The effectiveness of cryptographic techniques and access control, for example, may be a key consideration in selecting criteria. These security features can be found in different types of storage systems and are independent of how we classify storage systems.

Reliability。 Reliability is the way to consider the accessibility and functionality of a storage system across a period of duration.

A storage System with 99.99% reliability is expected to be down for about 4.5 minutes per month. A storage System with 99.999% reliability is expected to have less than 30 seconds of downtime per month.

A related metric-durability-is the degree to which data can be lost. Amazon Simple Storage Service (Amazon S3) uses a variety of data backups to promise 99.999999999% durability. This means that the probability of losing an object you store every year is 1e-09%.

It should be noted that these assessments are based on an underestimation of potential systemic failure assumptions. For example, if the data stored in three different data centers is backed up, and if the failure occurs randomly, all of the three probabilities of simultaneous failure are fairly small. However, if a manufacturing or design flaw exists in a disk drive, and all three of the scores are stored on the same type of drive, the three probability of loss is much higher.

accessibility. accessibility determines how storage devices are used. Object data storage, including Amazon S3 and Windows Azure block storage, allows you to store data as a Web-accessible object. Programs or interactive users can retrieve objects using the rest interface. Files are stored in the object repository, but these systems do not have the full range of features and choices of file systems. This type of storage is especially useful if multiple servers may need to access the data at the same time.

Object storage systems typically maintain a variety of data backups to improve accessibility and durability. Changing objects to keep all backups always, although it may also be possible for two users to see different results if they use different objects to back up service queries.

Block storage services, such as the Resilient Block storage (EBS) of Amazon Web Services (AWS), are more like direct or networked-attached storage systems than object storage. Block devices are better suited for applications that require low-level disk access, such as RAW format drivers, standard file systems, or consistent I/O performance.

As with physical storage devices, block storage devices are sometimes attached to a server. In this case, it works better with databases and other applications designed to share Linux or Windows file systems. In Amazon EBS, you can also choose to create the EBS capacity with preconfigured I/O performance. There are also additional costs for pre-allocation I/O, but they allow you to customize your I/O performance for your service requirements.

In addition, the EBS capacity can be replicated and the replicas look attached to other servers, allowing for higher levels of read performance. The read copy does not apply to what needs to be done in the extended practice content for High-volume read operations.

Size limit. Storage limits are another factor that takes into account block storage devices, providing virtually unlimited storage with EBS capacity limited to 1TB. Archived Storage-The third type of alternative cloud storage-provides low-cost storage, with Amazon Glacier $0.01 a month GB, but with a very high latency. Archived storage applies to situations where data must be retained, even if it is not used.