The T10 DIF (Data Integrity Field) and DIX (Data Integrity Extension) specifications provide mechanisms to guarantee end-to-end data integrity and protection in the face of silent data corruption in modern storage systems. However, the Multiple Devices (MD) software RAID driver in Linux does not fully leverage these capabilities to provide such end-to-end guarantees with widely-used RAID modes such as 5 and 6, thereby causing an 'integrity gap' in the Linux I/O stack. This paper describes the design and performance characteristics of a DIX-aware MD module that plugs this integrity gap with minimal overhead to client applications. A PI (Protection Information) operator is added in MD to handle the PI-related operations, and dedicated buffers for PI are allocated and managed in MD RAID-5/6 personality's stripe structures to generate, store, and verify the PI. This allows seamless exchange of PI information among end-applications running in user mode, file systems, the linux block layer, and PI-capable HBAs and drives. Our evaluations show that the DIX-aware MD module has the capability of detecting SDC with the tolerable performance penalty.
|Original language||English (US)|
|Title of host publication||Proceedings - 18th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing, CCGRID 2018|
|Publisher||Institute of Electrical and Electronics Engineers Inc.|
|Number of pages||7|
|State||Published - Jul 13 2018|
|Event||18th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing, CCGRID 2018 - Washington, United States|
Duration: May 1 2018 → May 4 2018
|Name||Proceedings - 18th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing, CCGRID 2018|
|Other||18th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing, CCGRID 2018|
|Period||5/1/18 → 5/4/18|
Bibliographical noteFunding Information:
This work is partially supported by a grant from CRAY and NSF awards 1305237, 1421913, 1439622 and 1525617. The authors also express their gratitude to Martin K. Petersen from Oracle, Chaitra Basappa from Broadcom and others who offer significant help during the experimental setup.
© 2018 IEEE.
- Linux kernel
- Software RAID
- T10 PI