Improving Online Restore Performance of Backup Storage Via Historical File Access Pattern

Online restore reduces the downtime during backup restore, such that users can operate on the already restored files even if the other files are still being restored. However, due to the inconsistency between the access sequence and the restore sequence, the file to be accessed currently is sometimes not restored, thereby leading to long-delay time to access the file. We propose two approaches, which build on users’ historical access sequence to schedule the restore sequence, in order to reduce users’ waiting time to file access: (i) the frequency-based approach, which restores files based on the access frequencies of historical files; and (ii) the graph-based approach, which preferentially restores the frequently accessed files as well as their correlated files. Trace-driven experiments on two datasets show that our approaches significantly reduce users’ waiting time.