Zfs Calculator

Using the ZFS Storage Calculator

This guide will walk you through using the ZFS Storage Calculator to estimate your storage capacity taking into account different RAID configurations and compression ratios. Please follow the steps below to accurately calculate the raw, usable, and effective storage capacities.

Step 1: Enter Individual Disk Size

• Locate the field labeled Individual Disk Size (TB).
• Input the storage size of a single disk in terabytes (TB). You can enter a value as small as 0.1 TB and as large as 100 TB, in increments of 0.1 TB.
• This field is required, so make sure to provide a valid input.

Step 2: Specify the Number of Disks

• Find the field labeled Number of Disks.
• Enter the total number of disks you wish to include in your storage pool. Values can range from 1 to 100 disks, with step increments of 1.
• This is a mandatory field, so a valid number must be entered before proceeding.

Step 3: Select RAID Configuration

• Look for the dropdown labeled RAID Configuration.
• Select the desired RAID level from the available options: Mirror (RAID1), RAIDZ1 (RAID5), RAIDZ2 (RAID6), or RAIDZ3.
• This is required to determine the redundancy and data protection strategy of your storage configuration.

Step 4: Choose Record Size

• Navigate to the Record Size dropdown.
• Pick a record size that matches your workload requirements. The options available are 4K, 8K, 16K, 32K, 64K, 128K, and 1M.
• This field is also required to calculate your storage efficiency more accurately.

Step 5: Enter Expected Compression Ratio

• Locate the Expected Compression Ratio input field.
• Enter the compression ratio you expect to achieve through ZFS compression. It can range from 1 (no compression) to 10.
• This is a crucial field for calculating the effective storage capacity, so ensure you provide a valid number.

Understanding Results

Once all the input fields are filled, the calculator will provide you with several important outputs:

• Raw Capacity: This is the total storage capacity if all disks were used without any redundancy. Calculated as (Individual Disk Size) x (Number of Disks).
• Usable Capacity (Before Compression): The actual data storage available after accounting for redundancy, depending on the RAID configuration.
• Effective Capacity (After Compression): The storage capacity you can utilize after considering both redundancy and data compression.
• Redundancy Overhead: The percentage of capacity used for redundancy, calculated as ((Raw Capacity – Usable Capacity) / Raw Capacity) x 100.
• Space Efficiency: The percentage of raw capacity effectively used for storing data, calculated as (Effective Capacity / Raw Capacity) x 100.

Reviewing these results will give you a comprehensive understanding of your storage setup’s capacity and efficiency. Adjust the inputs as needed to model different configurations and evaluate their impacts on storage capacity.