- If writing to a file, issue a sync of the dirty data for every number of
- blocks given. For example, if you give 32 as a parameter, fio will sync the
- file for every 32 writes issued. If fio is using non-buffered I/O, we may
- not sync the file. The exception is the sg I/O engine, which synchronizes
- the disk cache anyway. Defaults to 0, which means no sync every certain
- number of writes.
+ If writing to a file, issue an :manpage:`fsync(2)` (or its equivalent) of
+ the dirty data for every number of blocks given. For example, if you give 32
+ as a parameter, fio will sync the file after every 32 writes issued. If fio is
+ using non-buffered I/O, we may not sync the file. The exception is the sg
+ I/O engine, which synchronizes the disk cache anyway. Defaults to 0, which
+ means fio does not periodically issue and wait for a sync to complete. Also
+ see :option:`end_fsync` and :option:`fsync_on_close`.