LeoStor PACS film storage production system configuration scheme

Overall requirements

As one of the four key business systems of the hospital, PACS system undertakes the key function of "image aided analysis" of doctors. PACS film storage system is the key platform to support this business, with the following characteristics:

1. Long time: according to relevant laws and regulations, patient PACS data needs to be saved for 15 years;
2. Long cycle: doctors need to analyze the imaging data of patients for 3-5 years to evaluate the development of the disease;
3. High reliability: In case of hardware failure, the system should have self-healing ability, and the system access will not be affected;

On the storage system, it can be designed into two modes: 1) Production and archiving separation mode: the production system uses SSD full flash memory, and the archiving system uses ordinary SATA disks. Through the archiving software, the data of the production system is regularly archived to the archiving system; 2) Integrated mode: The storage system is required to have a higher cost performance ratio. Both modes are supported by LeoStor.

The first is incremental archiving through Longxiang LDM archiving system, and S3 object storage at the same time; Second, LeoStor single-thread 128K small files can reach 200MB/s, meeting the efficiency requirements of the production system, and supporting the integrated design of NAS and S3 object storage to reduce customers' investment in object storage. Take a Class III hospital as an example:

1. Storage capacity: 500GB of data needs to be saved every day, with a three-year plan;
2. Reliability: at least two disks fail at the same time, or two nodes fail at the same time;
3. Self-healing: automatic recovery of hard disk failure data, no more than 15 minutes per TB;
4. Extensibility: It is not necessary to stop sharing the file volume. The file volume can be expanded online by expanding the hard disk or node;
5. Doctor side: open the first picture in seconds, and turn the page smoothly;

Storage system design

LeoStor supports all current brand devices, including Feiteng and Kunpeng devices, and the LeoStor small file aggregation technology. It intelligently integrates hundreds of thousands of PACS small files into a large file, while maintaining the multi-read and multi-write characteristics of each small file. It ensures the second opening and smooth reading through the three-point cache technology of the client, storage node and metadata node;

LeoStor supports data redundancy of multiple copies and erasure code correction mode to meet the simultaneous failure of 1, 2, 3, and 4 nodes or hard disks. Based on cost and performance considerations, we recommend using LeoRaid 4+2:2 (N+M: M) redundancy mode, with the availability of 66%, raw capacity=548TB ÷ 66%=830TB. The system can automatically switch from Server Raid to Disk Raid when the number of nodes is insufficient.

Comparative advantages with friend systems:

1. Ceph distributed system: higher degree of productization than Ceph, clearer extension architecture, simpler system expansion, simpler integration deployment, higher utilization rate of hard disk, durable and predictable performance, and faster data recovery;
2. Hyperfusion system: Compared with hyperfusion system, it has higher stability, clearer system architecture, easier storage expansion, higher utilization rate of hard disk, lower delivery cost, more storage file protocols, and clearer data backup and archiving;

MDS node configuration

LeoStor supports the integrated deployment of metadata nodes and storage nodes. Friendly products need to add 2 SSD disks to the nodes for caching to increase performance, and the trend is also to use U2 SSD. Therefore, LeoStor does not increase hardware costs compared with its peers.

1. CPU: 2, each with more than 8 cores, and the dominant frequency is not less than 2.2GHz. If conditions permit, 4215R can be configured, and the dominant frequency is 3.2GHz
2. Metadata disk: It is recommended to configure an Intel S4610 SSD disk with a capacity of not less than 1.92GB. If conditions permit, you can configure a U2 SSD (P4610);
3. Number of metadata nodes: adding metadata nodes can significantly improve the retrieval efficiency of files with a scale of 2 billion, and 4 can be configured if conditions permit;

OSS node configuration

In the LeoRaid 4+2:2 scheme, the number of security nodes needs to be configured at least 4+2+2=8 nodes. Each node can not be fully configured with hard disks, and the number of nodes should be guaranteed first; LeoStar can be configured with full flash memory storage, full mechanical disk storage or mixed storage; Because the PACS system is not access intensive, the network bandwidth can be configured as 2 * 10GE SFP+10 Gigabit interface, and the full flash storage can be configured as 2 * 25GE SFP28.