Calculate disks, IOPS, and Throughput for Enterprise Storage
Storage Sizing & Performance Estimator
Enter your required usable capacity to find out how many disks you need.
RAID Requirements:Select a RAID level to see requirements.
Sizing Results
Required Disks
0
Physical Drives needed for Data
Raw Capacity
0 TB
Total Raw Space
Rec. Stripe Size
64KB
Based on Workload
Est. Read IOPS
0
Total Array Read Speed
Est. Write IOPS
0
Total Array Write Speed (w/ Penalty)
Read Throughput
0 MB/s
Sustained Sequential Read
Write Throughput
0 MB/s
Sustained Sequential Write
Performance Impact of Multiple LUNs:
Creating multiple LUNs on this same set of disks does not increase performance; it splits the available IOPS and Throughput shown above.
For example, if the array provides 10,000 IOPS and you create 2 active LUNs, they share those 10,000 IOPS.
Hot Spare Note: When using Dedicated Hot Spares, you must mark a Hot Spare for each Disk Group/LUN set to ensure redundancy.
Understanding Storage Architecture
Hardware vs. Software RAID
OEMs implement RAID through two primary methods:
Software RAID: Logic processed by the server's OS CPU. Cost-effective for entry-level, but consumes host resources.
Hardware RAID: Uses dedicated controllers (e.g., PERC, Smart Array) with battery-backed cache. Essential for enterprise performance to offload parity calculations from the main CPU.
RAID Levels & Requirements
RAID Level
Min Disks
Hot Spare Rec.
Description
RAID 0
2
N/A
Striping. Highest speed, zero redundancy.
RAID 1
2
1 Global/Ded
Mirroring. Good for Boot/Log drives.
RAID 5
3
1 Global/Ded
Striping + Parity. Balanced cost/performance.
RAID 6
4
1 Global/Ded
Double Parity. High fault tolerance for large arrays.
RAID 10
4
1 Global/Ded
Mirror of Stripes. Best performance for DBs.
Performance Tuning: Stripe Size (Block Size)
The Stripe Size (or Block Size) is the amount of data written to a single disk in the array before moving to the next disk.
64KB (Standard): The industry standard default. Ideal for databases (SQL/Oracle) and general virtualization. It provides a good balance between random I/O and sequential throughput.
128KB - 256KB: Often better for modern Windows File Servers or mixed workloads.
512KB - 1MB+: Recommended for Streaming Media, Video Editing, or Backup Repositories. These workloads read/write large sequential files, and larger blocks reduce the number of seek operations.
LUNs, Hot Spares, and Tiering
What is a LUN?
A LUN (Logical Unit Number) is a logical slice of the storage array presented to the OS as a volume. While you can carve 10 LUNs out of one set of disks, they all compete for the same physical IOPS of those disks.
Hot Spares: Global vs. Dedicated
A Hot Spare is an idle disk ready to take over if a drive fails.
Global: Protects any RAID group in the system.
Dedicated (LUN/Group wise): Assigned to a specific RAID group. Crucial when different groups use different disk speeds (e.g., Don't let a slow SATA spare rebuild a fast SSD array).
Storage Tiering
Tiering reduces cost by moving data based on access frequency (Heat):
Hot Data (High Perf): Automatically moved to SSD/NVMe tiers.
Cold Data (Low Perf): Automatically demoted to cheap NL-SAS/SATA tiers.