Best Practices for Capacity Optimization (Inline Deduplication and Compression)

Fault Tolerance

To achieve the best results while using Inline Deduplication and Compression, consider the following: Capacity Optimization supports both RAID 0 and RAID 5 (one disk fault tolerance).

Physical Disks and Performance

DataCore recommends using high performance SSDs and at least two physical disks per server for Capacity Optimization.

Slower disks or only one physical disk per server can cause inconsistent performance on Capacity Optimization enabled virtual disks. A minimum of 10 GB physical disk is required for enabling Capacity Optimization. Proofs of Concept (PoCs) should not start with less than 100 GB per physical disk.

NTFS Virtual Disks

To achieve maximum capacity savings in a virtual disk formatted as NTFS by the host with deduplication enabled, DataCore recommends keeping the allocation unit of NTFS the same as the IldcVolBlockSize parameter (the default value of IldcVolBlockSize is 128 KB). When the file sizes in the NTFS formatted volume are at least 10 MB, a better deduplication ratio is expected.

If the host is running Windows Server 2016, where the maximum allowed allocation unit for NTFS is 64 KB, consider configuring the IldcVolBlockSize parameter as 64KB to achieve maximum capacity savings.

Available Space Threshold and Performance

The performance of capacity-optimized virtual disks may suffer when the available space drops below 15%.

Encryption Backend Arrays

Using storage level encryption on backend arrays used for Inline Deduplication and Compression (ILDC) is not recommended.