Data Storage Systems: A Survey Abdullah Aldhamin July 29, 2013 CMPT 880: Large-Scale Multimedia Systems and Cloud Computing Course Project

Motivation Research interest in storage systems, specifically in SSDs

Outline Objective Overview Solid-State Drives Use Cases

Objective Storage system architectures in enterprise data centers. What is cloud storage? Integrating flash-based solid-state drives in large-scale storage systems.

Overview Different storage architectures in data centers: – Block I/O interface (DAS and SAN) – File I/O interface (NAS) – Is there a “better” solution? – Shortcomings for today’s computing…

Overview Cloud Storage: – What is cloud storage? Object-based storage – Example: Windows Azure Storage (WAS) – Some research problems

Overview Flash-based solid state drive: – What is it? – Pros and Cons. – How can we integrate it in large-scale storage systems? Future direction

Integrating SSDs in Large-Scale Storage Systems Considerations and Facts: – Non-uniform read access latencies, correlated with workload access pattern – Internal drive-specific operations impacts the performance – Internal fragmentation leads to performance degradation – More writes  write amplification  bad wear leveling – Performance vs. Lifetime vs. Cost

Integrating SSDs in Large-Scale Storage Systems SSD in Storage System SSD-Only System Hybrid System End-PointAccelerator Write Buffer Read Cache

Gordon: SSD-only HPC Cluster The first HPC cluster designed with SSD-only storage Optimized to utilize SSDs high bandwidth, for data-intensive applications

Gordon … (Cont’d) Design goals: – Reduce performance gap between processor and I/O in large-scale data-intensive computing – Improve the system performance – Less power

Gordon… (Cont’d) How SSD is integrated? – Replaced conventional hard disks with SSDs – Major device-level modification: New flash translation layer

Gordon… (Cont’d) Costly $$$ Not suitable for widespread adoption Requires major device level modification – Optimized for specific workloads

Hybrid: Griffin Griffin hybrid storage system – SSD is an end-point store for the data – Uses HDDs as write-back buffers Log-structured HDDs to buffer incoming writes Extends SSD lifetime

Hybrid: Hystor Hybrid storage system – SSD is used to improve I/O performance Read cache Write-back buffer – Challenge: What data to should be cached to gain from SSD performance and improve performance? Minimum system changes.

Conclusion The choice of I/O interface allows for different storage access features Cloud storage continues to grow to accommodate for the overflowing of data collected Solid state drive has become an instrumental player in storage systems: but how can we best use it?