dm-cache, a device mapper target based on SSD

This proposal has been rejected.


One Line Summary

In this session, we will talk about dm-cache, a device mapper target which uses SSD as a cache for some large and slow devices like SAS or SATA.


Nowadays, SSD begins increasingly popular in production system. But because of its high price and relately small volume size, it can’t be used to store much data.

So using a SSD as a cache for a large but slow device comes up in our minds. flashcache is developed by facebook and used there, bcache is created as a plugin in block layer. But all these aren’t flexible and generic enough for us and we can’t tune them easily to be fit for different working scenarios.

In this talk, we will introduce dm-cache, a new device mapper target which uses one device as a cache for another device. The infrastructure is more flexible and we use in for different working scenarios such as squid, my sql databases etc. Some test results will also be shared so that we know how much it can improve the applications in our company, taobao1.

This talk will take around 30 minutes. If you are interested on how to use SSD in some very large Internet company and how we use dm-cache to improve the transaction in this Chinese largest online shopping website, please come. :-)

1 Taobao is the biggest online shopping website in China, we have more than 370 million registered users as of the end of 2010 and currently hosts more than 800 million product listings.


  • Biography

    I have worked in the linux kernel for about 5 years. Most of my time has been spent in ocfs2(oracle cluster file system). And now I am working on block layer and file system issues.