Solid State Disks (SSDs) based on flash and other non-volatile
memory technologies reduce storage latencies from 10s of milliseconds to 10s or
100s of microseconds, transforming previously inconsequential storage overheads
into performance bottlenecks. This problem is especially acute in storage area
network (SAN) environments where complex hardware and software layers
(distributed file systems, block severs, network stacks, etc.) lie between
applications and remote data. These layers can add hundreds of microseconds to
requests, obscuring the performance of both flash memory and faster, emerging
non-volatile memory technologies. We describe QuickSAN, a SAN prototype that
eliminates most software overheads and significantly reduces hardware overheads
in SANs. QuickSAN integrates a network adapter directly into SSDs, so the SSDs
can communicate directly with one another to service storage accesses as
quickly as possible. QuickSAN can also give applications direct access to both
local and remote data without operating system intervention, further reducing
software costs. Our evaluation of QuickSAN demonstrates remote access
latencies of 20us for 4KB requests, bandwidth improvements of as much as 163x
for small accesses compared with an equivalent iSCSI implementation, and
2.3-3.0x application level speedup for distributed sorting. We also show that
QuickSAN improves energy efficiency by up to 96% and that QuickSAN's networking
connectivity allows for improved cluster-level energy efficiency under varying
load.
Pre-2018 CSE ID: CS2013-0995
