--rebuild-indexes holds on to disk space during --prepare
|Percona XtraBackup||Status tracked in 2.2|
After doing a --compact backup with xtrabackup I was doing a --prepare --rebuild-indexes, and found that the temporary files that are created (.ibd.tmp) during the expanding phase are deleted but not flushed from disk. This means that in order to do a --prepare of the backup, you need the entire size of the backup free on disk on top of the backup itself (and expanded tables), which may be unmaintainable for very large backups.
As the tables are expanded individually then the temporary file deleted, can these deleted temporary files not be flushed so as to free the disk space they use immediately?