.TH SYNC 2 "12 February 1983" .UC 4 .SH NAME sync \- update super-block .SH SYNOPSIS .B sync() .SH DESCRIPTION .I Sync causes all information in core memory that should be on disk to be written out. This includes modified super blocks, modified i-nodes, and delayed block I/O. .PP .I Sync should be used by programs which examine a file system, for example .I "fsck, df," etc. .I Sync is mandatory before a boot. .SH "SEE ALSO" fsync(2), sync(8), update(8) .SH BUGS The writing, although scheduled, is not necessarily complete upon return from .IR sync .