RAID Storage Calculator
Calculate usable storage capacity with different RAID configurations
Typically 5-10% for most filesystems
RAID Storage Calculator: Estimate Your RAID Capacity
This RAID calculator helps you find out how much storage you really get with RAID. Use it to estimate your storage space, how safe your data is, and how much space you can actually use. Understanding your RAID configuration is essential for building efficient and reliable storage systems.
What is RAID?
RAID (Redundant Array of Independent Disks) is a technology that combines multiple physical disk drives into one logical unit for improved performance, increased storage capacity, or data redundancy. Different RAID levels offer different benefits, balancing factors like speed, protection, and usable capacity.
How to Use This RAID Calculator
- Enter the number of disks you plan to use in your RAID array
- Enter the capacity of each disk and select the appropriate unit (TB, GB, etc.)
- Set the filesystem overhead percentage (typically 5-10%)
- Select your desired RAID level from the options provided
- View the calculated results showing your usable capacity and reliability details
The calculator shows your results immediately - no need to click a button!
Understanding RAID Levels
Different RAID levels offer different benefits. Some focus on speed, while others focus on keeping your data safe:
- RAID 0 (Striping): Combines all your hard drives into one big, fast drive. But if one drive fails, you lose all your data.
- RAID 1 (Mirroring): Mirrors your data across two drives. If one drive fails, the other keeps your data safe. You only get half the total storage space.
- RAID 5 (Striping with Parity): Uses a special calculation to protect your data. It needs at least three drives and can survive one drive failure.
- RAID 6 (Double Parity): Similar to RAID 5 but with double protection. Can survive two simultaneous drive failures but requires at least four drives.
- RAID 10 (1+0): Combines RAID 1 and RAID 0. It mirrors data and spreads it across multiple drives for both speed and safety.
- ZFS RAID (RAIDZ): ZFS implementation offering better protection against data corruption with various levels of redundancy.
How RAID Affects Storage Capacity
RAID affects your storage capacity because some RAID levels use space for data protection. Here's how different RAID levels impact your usable storage:
| RAID Level | Usable Capacity Formula | Storage Efficiency | Example with 4×2TB Disks |
|---|---|---|---|
| RAID 0 | N × Disk Size | 100% | 8TB |
| RAID 1 | 1 × Disk Size | 50% with 2 disks | 2TB |
| RAID 5 | (N-1) × Disk Size | 67-94% | 6TB |
| RAID 6 | (N-2) × Disk Size | 50-90% | 4TB |
| RAID 10 | (N/2) × Disk Size | 50% | 4TB |
RAID Redundancy and Data Protection
RAID redundancy means having extra copies or parity information for your data. This protects you from losing data if a hard drive fails:
- No Redundancy (RAID 0): All drives must work for the array to function. One drive failure causes complete data loss.
- Mirroring (RAID 1, 10): Creates exact copies of data. Can lose specific drives without data loss.
- Parity (RAID 5, 6): Stores special parity information to reconstruct data if a drive fails.
- Multiple Parity (RAID 6, RAIDZ3): Can survive multiple simultaneous drive failures.
Important: RAID is not a backup solution! While RAID protects against drive failures, it doesn't protect against accidental deletion, corruption, ransomware, or disasters.
Choosing the Right RAID Level for Different Scenarios
| Scenario | Recommended RAID Level | Benefits |
|---|---|---|
| Home media server | RAID 5 | Good balance of storage and protection |
| Gaming PC | RAID 0 | Faster game loading times |
| Small business server | RAID 10 | Speed and data safety |
| Photo/Video editing | RAID 5/10 | Large storage and fast access |
| Critical data storage | RAID 6 | Survives two drive failures |
RAID Performance Considerations
Different RAID levels impact performance in various ways:
- Read Performance: RAID 0, 10, and 5 offer improved read speeds by reading from multiple disks simultaneously.
- Write Performance: RAID 0 and 10 provide the best write performance. RAID 5 and 6 have slower writes due to parity calculations.
- Rebuild Time: When a drive fails, RAID 1 and 10 rebuild faster than RAID 5 and 6. Larger arrays take longer to rebuild.
- Disk Size Impact: As disk sizes increase, the chance of encountering another failure during a rebuild increases, especially with RAID 5.
Filesystem Overhead Explained
When formatting drives, the filesystem itself requires some space for its structures and metadata. This overhead reduces the actual usable capacity:
- Most modern filesystems (NTFS, ext4, XFS) have approximately 3-7% overhead
- ZFS can use 7-10% for metadata and reserve space
- Overhead increases as you store many small files rather than fewer large files
- Some filesystems reserve space for system use (e.g., ext4 reserves 5% by default)
Questions About RAID Storage
RAID Storage Calculator: Related Tools
Try these other helpful calculators:
- Storage Space Calculator: Determine usable storage capacity with different RAID levels.
- IOPS Calculator: Understand the performance implications of different RAID configurations.
- Data Transfer Calculator: Relates to how quickly data can be read/written from storage.
Optimize your storage redundancy and performance with the RAID Storage Calculator!
About RAID Storage Calculator
The RAID Storage Calculator is a comprehensive tool designed to help users accurately plan and understand their storage array configurations. Whether you're building a new system, upgrading existing storage, or simply exploring options, this calculator provides precise estimates of usable capacity, data redundancy, and performance characteristics based on your specific RAID level, disk quantity, and individual disk capacities.
This calculator supports a wide range of RAID configurations including standard levels (RAID 0, 1, 5, 6, 10), nested RAID levels (RAID 50, 60), and ZFS-specific implementations (RAIDZ1, RAIDZ2, RAIDZ3), as well as JBOD (Just a Bunch Of Disks). For each configuration, it performs complex calculations to determine total raw capacity, usable storage space, capacity efficiency, and the impact of filesystem overhead, providing results in the most appropriate storage units from gigabytes to petabytes.
Unlike simple capacity calculators, this tool provides comprehensive insights into reliability and performance aspects of each RAID level. It accounts for critical factors like fault tolerance (maximum tolerable disk failures), read and write performance characteristics, minimum disk requirements, and storage efficiency. The calculator dynamically updates as you adjust parameters, offering immediate feedback on how different configurations impact your storage solution's capacity, redundancy, and performance profile.
This calculator serves system administrators planning enterprise storage solutions, IT professionals configuring NAS systems, media professionals designing high-capacity workstations, home server enthusiasts building media servers, and anyone needing to make informed decisions about data storage configurations. By providing detailed information about each RAID level's strengths and limitations, it helps users balance their specific requirements for storage capacity, data protection, and performance to create optimal storage solutions for their unique needs.