Building Large Storage Based On Flash Disks.
Ilia Petrov, Guillermo G. Almeida, Alejandro Buchmann, Ulrich Gräf · 2010
Flash SSDs are a technology that has the potential of drastically changing the architecture of a DBMS. In this paper we examine the properties of a storage space built on SSDs with RAID and how these affect data intensive systems. While we observed the expected performance improvements of one to two orders of magnitude of SSD-only storage over HDD storage, RAID-SSD systems showed interesting effects and large performance degradation: (a) the SSD read-write asymmetry and the write behavior are amplified due to RAID; (b) scalability issues in a RAID-based storage system appear because of inadequate controllers; (c) fragmentation and distribution issues affect performance much more than expected. 1.