Preventing fast wear-out of flash cache with an admission control policy
- 주제(키워드) Admission control , Flash cache , Flash memory , LRU , Replacement policy
- 관리정보기술 faculty
- 등재 SCIE, KCI등재, SCOPUS
- 발행기관 Institute of Electronics Engineers of Korea
- 발행년도 2015
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000120192
- 본문언어 영어
- Published As http://dx.doi.org/10.5573/JSTS.2015.15.5.546
초록/요약
Recently, flash cache is widely adopted as the performance accelerator of legacy storage systems. Unlike other cache media, flash cache should be carefully managed as it has peculiar characteristics such as long write latency and limited P/E cycles. In particular, we make two prominent observations that can be utilized in managing flash cache. First, a serious worn-out problem happens when the working-set of a system is beyond the capacity of flash cache due to excessively frequent cache replacement. Second, more than 50% of data has no hit in flash cache as it is a second level cache. Based on these observations, we propose a cache admission control policy that does not cache data when it is first accessed, and inserts it into the cache only after its second access occurs within a certain time window. This allows the filtering of data disruptive to flash cache in terms of endurance and performance. With this policy, we prolong the lifetime of flash cache 2.3 times without any performance degradations. © 2015, Institute of Electronics Engineers of Korea. All rights reserved
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