1) SSDs provide significantly better performance than HDDs for WordPress.com, reducing costs by 75% while improving performance and capacity 6 times. 2) An experiment replacing HDD RAID with SSDs was very successful, but initial production deployment had critical bugs and required restarting the migration process. 3) While SSDs save money and users' time, maximizing their performance requires substantial research, testing, and software optimization from system administrators.

1. Why SSDs are
Awesome
WordCamp NYC 2009
Barry Abrahamson

2. Me
• Systems Wrangler at Automattic
• Sysadmin, systems architect, DBA
• Used to live in NYC, now live in Ft. Worth,
Texas

3. WordPress.com
• Over 9 million blogs and 11 million users
• 50+ million page views/day
• 1.2 billion queries/day just for post and
comment data
• 300+ database servers

4. Queries per hour

5. Before
• 4 x 15k RPM
SAS drives
• RAID 0
• RAID
Controller
with BBWC
• $1200

6. Road to SSDs
• January 2008 - Mtron experiment (FAIL)
• April 2009 - Intel experiment (SUCCESS)
• May 1, 2009 - Production deployment
• May 15, 2009 - Critical bug found
• May 30, 2009 - Start over w/ prod deploy
• July 2, 2009 - Migrations complete!

7. After
• 1 x Intel X25-M
SSD 80GB
• No RAID
controller
• $300
http://www.flickr.com/photos/xuoan-dailies/3235208908/

8. Awesome
• 75% cheaper than fast HDDs + RAID
controller
• 6x real-world performance/capacity
improvement
• Reliability: 150+ drives in production for 6+
months, only 1 failure.

9. Less than Awesome
• Saves money and your user’s time, but likely
not your (sysadmin’s) time
• Lots of research, tweaking, benchmarking,
hacking necessary to achieve maximum
performance
• Most software is designed to reduce disk
seeks

11. Contact me!
• barry [ at ] automattic [dot ] com
• http://barry.wordpress.com

12. Questions!
(about whatever you want to ask)