Drupal Performance Improvement via SSD Technology

A Sun ISV Engineering Test Report

Eric R. Reid, ISV Engineering
Sun Microsystems, Inc.
11 March 2009

Full Test Report

Synopsis

Introduction

Drupal is a leading Open Source Content Management System, written in PHP for the AMP stack. While Drupal does not usually place an extremely heavy burden on I/O subsystems 'out of the box', Sun expects that the introduction of Solid State Disk (SSD) Technology in upcoming server products will provide performance increases. This document details the testing performed to identify and quantify such increases.

Drupal 6 was to be tested, using a Sun-developed synthetic workload, on Solaris 'Nevada' and the Coolstack AMP stack. Configurations would be created and measured which provided three types of I/O subsystem support:

Traditional internal Hard Disk Drive (HDD) storage
New internal SSD devices as whole, functionally identical replacements for HDDs
Utilizing ZFS Hybrid Storage Pools (HSPs), which effectively mix SDD and HDD technologies (reference: http://blogs.sun.com/brendan/entry/test)

Conclusions

SSDs do provide apples-to-apples performance improvement over HDDs (even 10K RPM drives). One challenge with AMP-based packages such as Drupal is that they are not often I/O-bound unless precisely tuned for particular workloads. As such, 'out of the box' performance gains might not justify the increased cost.

Properly-tuned Drupal deployments which stress I/O subsystems will likely see greater SSD-vs-HDD performance increases than detailed in this report.

ZFS Hybrid Storage Pools provide a more cost-effective option in which some SSD speed advantages can be realized without the full upcharge of SSDs.

Improved Performance Via SSDs