STORING DATA IN A LOG-STRUCTURED FORMAT IN A TWO-TIER STORAGE SYSTEM

The disclosure herein describes storing data using a capacity data storage tier and a smaller performance data storage tier. The capacity data storage tier includes capacity data storage hardware configured to store log-structured leaf pages (LLPs), and the performance data storage tier includes performance data storage hardware. A virtual address table (VAT) includes a set of virtual address entries referencing the LLPs. A tree-structured index includes index nodes referencing the set of virtual address entries of the VAT. Data to be stored is received, and at least a first portion of metadata associated with the received data is stored in the LLPs using the VAT, and at least a second portion of metadata associated with the received data is stored in the performance data storage tier. The architecture reduces space usage of the performance data storage tier.