Journaling of Journal

02 Jun 2015

Journaling of Journal Is (Almost) Free on FAST 2014.

Journaling is the technology to protect data consistency and durability despite sudden system crashes. However, while a robust journaling file system can protect the corruption of the file system itself, it can not protect the user’s data. As a results, many applications use rollback-recovery journaling to record REDO or UNDO information in a log file. This journaling (file system journal) of journal performs unnecessary write, thus cause performance penalty.

Because the log file of applications is a safe journal, this paper propose selectively reduce the file system journal operations. Single-I/O use buffer to merge multiple application I/Os into a single commit. File-Adaptive Journaling selectively provide file level option of journal preference, such as ordered journaling and full data/metadata journaling.

Additional Read: Consistency Cost in NVM-based Single Level Systems.