RAID Card Overview
- DELL array card (RAID card)
RAID, Redundant Array of Independent Disks, is a technology that combines multiple independent hard disks (physical hard disks) into a group of hard disks (logical hard disks) in different ways to provide higher storage performance and data backup than a single hard disk.
The different disk array configurations are called RAID Levels (RAID Levels).
Centralized management idea: resources are integrated and managed with unified standards.
- Basic role:
When the amount of data on a website is very large, a single hard disk may not be able to meet the demand. In this case, multiple hard disks can be purchased, consolidated into one large disk, and partitioned (virtual disk) on this large disk to store the data. Another important feature is redundancy (backup), which provides data backup to improve data security by putting multiple hard disks together.
- Characteristics (vs. individual hard disks):
- Similarities: Disk arrays act like individual hard disks and can be partitioned, formatted, etc. by the user.
- Difference: Disk arrays store at much higher speeds than individual hard disks and provide automatic data backup. The data backup feature allows you to restore corrupted data by backing up the information in the event of data corruption, thus safeguarding the security of your data.
RAID levels and their characteristics
There are various ways to integrate RAID, mainly including: RAID 0, RAID 1, RAID 5, RAID 10. RAID cards are usually used to connect hard disks to enhance storage performance and redundancy.
RAID Level Comparison
- RAID 0
- Features: Also known as Stripe or Striping, it represents the highest storage performance of all RAID levels.RAID 0 improves overall access performance by spreading data across multiple disks for parallel access.
- Read and write performance: best (due to increased parallelism).
- Security: Minimum (no redundancy)
- Disk Utilization: Highest (100%).
- Applications: For environments with high performance but low security requirements, such as individual users or graphics workstations.
- RAID 1
- Features: Also known as Mirror or Mirroring, it provides the highest level of data security.RAID 1 ensures data security by completely copying the data to another hard disk.
- Read and write performance: Read performance is comparable to a single disk, but write operations require two writes.
- Security: Maximum (100% redundancy).
- Disk utilization: minimum (50%).
- Applications: For environments with high data security requirements, such as critical servers and database storage.
- RAID 5
- Features: A compromise that combines storage performance, data security, and storage costs.RAID 5 does not back up data, but rather decentralizes the storage of data and parity information. Parity information is used to recover corrupted data.
- Read and write performance: Read performance is close to RAID 0, but write speed is slower.
- Security: Medium (can recover from a single disk failure).
- Disk Utilization: High (higher than RAID 1).
- Applications: For environments that require a balance of performance and data security, such as database and file servers.
- RAID 10 (RAID 0+1)
- Features: Combining the advantages of RAID 0 and RAID 1, RAID 10 provides similar storage performance to RAID 0 and the same data security as RAID 1.
- Read and write performance: Read performance is comparable to RAID 0, write performance is comparable to RAID 1.
- Security: Same as RAID 1 (100% redundancy).
- Disk utilization: same as RAID 1 (50%).
- Applications: For areas that require stringent data security as well as high-performance access, such as finance, commercial supermarkets, and records management.
RAID Level Selection Recommendations
- Single server: Use RAID 1 for the system disk.
- Database/storage servers: Use RAID 10 for the master and RAID 5 or RAID 0 for the slaves (RAID 10 is recommended to reduce maintenance costs).
- Web server: If the amount of data is not large, you can choose RAID 5 or RAID 0 (single disk).
- Multiple monitoring/application servers: RAID 5 or RAID 0 is recommended.
