sync man page on CentOS

Man page or keyword search:  
man Server   8420 pages
apropos Keyword Search (all sections)
Output format
CentOS logo
[printable version]

SYNC(8)			   Linux Programmer's Manual		       SYNC(8)

NAME
       sync - synchronize data on disk with memory

SYNOPSIS
       sync [--help] [--version]

DESCRIPTION
       sync  writes any data buffered in memory out to disk.  This can include
       (but is not limited to)	modified  superblocks,	modified  inodes,  and
       delayed	reads and writes.  This must be implemented by the kernel; The
       sync program does nothing but exercise the sync(2) system call.

       The kernel keeps data in memory to avoid doing (relatively  slow)  disk
       reads  and  writes.   This  improves  performance,  but if the computer
       crashes, data may be lost or the	 filesystem  corrupted	as  a  result.
       sync ensures that everything in memory is written to disk.

       sync should be called before the processor is halted in an unusual man‐
       ner (e.g., before causing a kernel  panic  when	debugging  new	kernel
       code).	In  general,  the  processor  should be halted using the shut‐
       down(8) or reboot(8) or halt(8) commands, which will attempt to put the
       system in a quiescent state before calling sync(2).  (Various implemen‐
       tations of these commands exist; consult your  documentation;  on  some
       systems one should not call reboot(8) and halt(8) directly.)

GNU STANDARD OPTIONS
       --help Print a usage message on standard output and exit successfully.

       --version
	      Print version information on standard output, then exit success‐
	      fully.

       --     Terminate option list.

ENVIRONMENT
       The variables LANG, LC_ALL, LC_CTYPE, and LC_MESSAGES  have  the	 usual
       meaning.

CONFORMING TO
       POSIX.2

NOTES
       On  Linux,  sync	 is  only  guaranteed to schedule the dirty blocks for
       writing; it can actually take a short time before all  the  blocks  are
       finally	written.   The	reboot(8)  and halt(8) commands take this into
       account by sleeping for a few seconds after calling sync(2).

       This page describes sync as found in the fileutils-4.0  package;	 other
       versions may differ slightly.

SEE ALSO
       sync(2), halt(8), reboot(8), update(8)

GNU fileutils 4.0		    1998-11			       SYNC(8)
[top]

List of man pages available for CentOS

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net