Block storage type #
- Cloud dish
- shared memory block
- local disk
# Cloud disk classification
-ESSD cloud ultra-high performance disk
-SSD high cloud disc random read performance
- high cloud disc random read performance and the like
- Normal cloud generally disc random read performance
Cloud ESSD disc with low latency, fast response, powerful data throughput, suitable for delay-sensitive applications or the I / O-intensive business scenario. For example:
A typical OLTP (Online Transaction Processing, OLTP) relational database, such as MySQL, PostgreSQL, Oracle, SQL Server and so on.
NoSQL non-relational databases such as MongoDB, HBase, Cassandra and so on.
Real-time analytics applications such as Elasticsearch distributed logging and ELK (Elasticsearch, Logstash, Kibana) log analysis.
| ESSD cloud drive properties | Performance level III | Performance level II | Performance level I |
| Performance level | PL3 | PL2 | PL1 |
| Cloud disk capacity | 1261-32768 | 461-32768 | 20-32768 |
| The largest single disk IOPS | 1，000，000 | 100，000 | 50，000 |
| The maximum throughput of a single disk | 4，000 | 750 | 350 |
How to choose the disk # ESSD cloud performance level the same performance level of the three kinds of single-disc disc ESSD cloud capacity range, GiB support 20 is - 32 , 768 capacity range of GiB. Three performance levels of different core difference is that the individual disk performance limit. ESSD cloud disk may be used as a system disk and a data disk, the following recommendations apply to disk as a data disk ESSD cloud scenes. ESSD PL1 for concurrency limit the I / O performance requirements medium, a more stable read and write delay business scenario.
For small and medium databases such as MySQL and SQLServer scene, small and medium-scale ELK log clusters, SAP and Oracle and other enterprise-class commercial software, the container application. If you've been using a disk or SSD efficient cloud cloud disk, you can prefer ESSD PL1 as a data disc, bearing similar business system data.
ESSD PL2 for concurrency limit the I / higher performance requirements O, write latency stable business scenarios. For medium-sized relational databases and NoSQL databases, medium-sized ELK log clusters, SAP and Oracle and other enterprise-level business software. If you've been using a local disk or SSD SSD cloud instance specification (i1, i2, i2g), may be preferred ESSD PL2 as a data disc, bearing similar business system data. ESSD PL3 suitable for concurrent limit the I
/ high O performance, read and write latency very stable business scene. suitable for medium and large business core relational database and NoSQL databases, large systems such as SAP and Oracle. If you've been using a high-class specification (16-core vCPU above) local SSD Instance Specifications (i1, i2, i2g), may be preferred ESSD PL3 as a data disc, bearing similar business system data.
# Three out copies cloud technology
Ali cloud data storage system, there are three types of roles, called Master, Chunk Server and Client. You are a write operation, through the layers of the conversion will eventually be handed over to Client to perform the execution process briefly described as follows:
Client calculate the write operation corresponding Chunk.
Client inquiries stowed position three copies of the Chunk to the Master.
Master Client based on the results returned, issued to three Chunk Server write requests.
If the three are written successfully, Client to return to your success; on the contrary, Client to return your failure.
When a node has data corruption, or on one of the hard disk data node fails, the effective number of copies of the cluster portion Chunk will be less than 3. Once this happens, Master will initiate replication, replicate data between Chunk Server, the effective number of copies of all cluster Chunk of up to 3 copies.
# Cloud disk encryption
Use cloud disk encryption function, the system will transmit the data from the ECS to automatically encrypted instance cloud disc and the data is automatically decrypted when read. Encryption and decryption performed on the host where the ECS example, the transmission data from the ECS instance cloud encrypted disk.
- After creating an encrypted cloud disk, the system will have the following data encryption
Static data cloud disk
data between disk and cloud instances transmission (data does not support encryption system disk)
from all snapshots disk encryption cloud created (ie, encrypted snapshot)
- Limitations
only cloud disk encryption, encryption can not be a local disk.
Only encrypted data disc, can not encrypt the system disk.
Existing non-encrypted disk can not be directly converted to encrypted disk.
Cloud disk that has been encrypted, the encryption can not be converted to a non cloud disk.
Non-existing snapshot generated encrypted disk can not be directly converted into encrypted snapshot.
Snapshots can not convert non-encrypted encryption snapshots.
Mirroring can not be shared with encrypted snapshot.
You can not copy the image across geographies with encrypted snapshot.
You can not export encryption mirror with snapshots.
Each region each user can not select the user master key (CMK) own, generated for you by the system.
User Master Key (CMK) for each region ECS system was created, the user can not be deleted, but not free of charge.
The user does not support the replacement master key for associating the cloud disc after decryption of encrypted disc cloud.