Towards Reliable Storage Systems

Tuesday, February 17, 2009 - 5:18pm

Computer Engineering Program Seminar

Haryadi Gunawi
U. of Wisconsin, Madison
Friday, February 20, 2009
ECE Conference Rm (HFH Rm 4164)

Title: Towards Reliable Storage Systems

Three trends will dominate the storage systems of tomorrow: users are
storing increasingly massive amounts of data, storage software
complexity is growing, and the use of cheap and less reliable hardware
is increasing. These trends present us with a terrific challenge: How
can we promise users that storage systems work robustly in spite of
their massive software complexity and the broad range of disk failures
that can arise? Unfortunately, current approaches describe recovery
in thousands of lines of intricate, low-level C code and it is
scattered throughout. As a result, current storage systems are not

In this talk, I will present how we build a new generation of more
robust and reliable storage systems by adhering to the idea that
complexity is the enemy of reliability. Specifically, I will present
new online and offline reliability frameworks (I/O Shepherding and
SQCK) that advocate a higher-level strategy where the logic of
reliability policies can be described clearly and concisely. With I/O
shepherding, file system administrators can write disk-failure
policies (such as retry, parity, mirrors, checksums, sanity checks,
and data structure repairs) in a few lines of code in a single locale.
With SQCK, file system developers can separate the logic of hundreds
of data structure repairs from their low-level implementation. I will
also discuss other interesting findings that show how storage system
reliability is difficult to achieve in current approaches.

BIO: Haryadi Gunawi is a Ph.D. candidate at University of Wisconsin,
Madison under the supervision of Prof. Andrea Arpaci-Dusseau and
Prof. Remzi Arpaci-Dusseau. His research focuses on file systems and
operating systems. Beyond that, his research experience also spans
cross-disciplinary areas such as software engineering, distributed
systems, networking, and databases. Haryadi earned a B.S. in Computer
Engineering, a B.S. in Computer Science, and an M.S. in Computer
Science, all from University of Wisconsin.