Thursday, March 6, 2003
Noon - 1:30 pm
Intel Seminar (417 S. Craig Street - 3rd Floor)
EVENTS PAGE: http://www.intel-research.net/pittsburgh/events.htm
StarFish: Highly-available Block Storage
The world's growing dependency on data increases the need for highly-available
data storage. Geographically-dispersed replicas can provide data availability
despite a major site Failure, and are increasingly affordable given the
price-performance trends of storage devices, servers, and high-speed networks.
In this light we present StarFish, a block storage system built from commodity
servers running FreeBSD, which are connected by standard high-speed IP
networking gear. StarFish achieves high availability by transparently
replicating data over multiple storage sites. StarFish is accessed via
a host-site appliance that masquerades as a host-attached storage device,
hence it requires no special hardware or software in the host computer.
We show that a StarFish system with 3 replicas and a write quorum size
of 2 is a good choice, based on a formal analysis of data availability
and reliability: 3 replicas with individual availability of 99% and a
write quorum of 2 gives better than 99.9999% overall data availability.
Although StarFish increases the per-request latency relative to a direct-attached
RAID, we show how to design a highly-available StarFish configuration
that provides most of the performance of a direct-attached RAID on an
I/O-intensive benchmark, even during the recovery of a failed replica.
Moreover, the third replica may be connected by a link with long delays
and limited bandwidth, which alleviates the necessity of dedicated communication
links to all replicas.
Eran Gabber received his Ph.D. in Computer Science from Tel-Aviv University,
Israel, in 1993. From 1993 to 1995 he was the principal researcher of
nSOF Parallel Software, Ltd., a startup company in Israel. He joined Bell
Laboratories (first a part of AT&T, later a part of Lucent Technologies)
in 1995, where he is currently a distinguished member of technical staff.
His research interests include operating systems, file and storage systems,
tools for building specialized systems, quality of service, network management,
Internet privacy, and electronic commerce.
Contact Kim Kaan, 412-605-1203,
or visit http://www.intel-research.net.
SDI Home: http://www.pdl.cmu.edu/SDI/