Best Practices for Capacity Optimization (Inline Deduplication and Compression)

Fault Tolerance

To achieve the best results while using Inline Deduplication and Compression, there are some important things to consider. The first, Capacity Optimization in and of itself does not provide any fault tolerance. DataCore recommends using storage with built-in redundancy built into it, such as a RAID configuration.

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.

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%.