Storage Controller Load Reduction via Pre-Allocation in Virtual Volume Cloning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In storage systems managing virtual volumes with Thin Provisioning, high load on the storage controller occurs when a clone virtual volume is written to, as it needs to read user data from a real area and allocate a new real area, even if a real area is already allocated to the corresponding first virtual area.
Innovation Solution
Allocate a second real area to the second virtual area before writing occurs, allowing data to be stored in physical areas corresponding to the first real area, thereby avoiding the need for the storage controller to read user data from the first real area and reducing the load on the storage devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a real area is not allocated to the second virtual area (clone) and data is read from the first real area to the cache memory during writes, then the storage system can implement Thin Provisioning, but the load on the storage controller becomes high
Solution Approach 1:
The patent applies preliminary action by allocating a second real area to the clone virtual volume in advance, before any write operations occur. This pre-allocation ensures that when writes happen to the clone, the data can be directly written to the pre-allocated second real area without requiring the storage controller to read data from the first real area and perform complex allocation operations during the write process, thereby reducing the storage controller load
2Ease of operation
If data is read from the first real area to the cache memory and copied during writes to the second virtual area, then the write operation can proceed, but the load on the storage controller and storage devices increases
Solution Approach 1:
The patent pre-allocates the second real area to the clone virtual volume before write operations occur. This allows write operations to proceed efficiently by directly writing data to the pre-allocated second real area, eliminating the need to read data from the first real area to the cache memory and perform copy operations during the write process
Solution Approach 2:
The patent implements a copying mechanism where the second real area is allocated as a copy destination for the clone virtual volume. By having the second real area pre-allocated and ready, the system can efficiently copy or write data to the clone without requiring real-time allocation or complex cache memory operations, thereby improving processing efficiency
Data Source
AI summary
A second virtual volume having a plurality of second virtual areas is a clone of a first virtual volume having a plurality of first virtual areas. A first real area is allocated from a pool of real areas and based on storage devices to the first virtual volume. A storage controller allocates a second real area to the second virtual area before a write occurs in the second virtual area corresponding to the first virtual area to which the first real area is allocated. A physical area is allocated to a logical area corresponding to the first real area in each storage device, and data based on user data stored in the first real area is stored in the physical area. Each storage device allocates the physical area allocated to the logical area corresponding to the first real area to a logical area corresponding to the second real area.