Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

sync(2) [opensolaris man page]

sync(2) 							   System Calls 							   sync(2)

NAME
sync - update super block SYNOPSIS
#include <unistd.h> void sync(void); DESCRIPTION
The sync() function writes all information in memory that should be on disk, including modified super blocks, modified inodes, and delayed block I/O. Unlike fsync(3C), which completes the writing before it returns, sync() schedules but does not necessarily complete the writing before returning. USAGE
The sync() function should be used by applications that examine a file system, such as fsck(1M), and df(1M), and is mandatory before rebooting. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ SEE ALSO
df(1M), fsck(1M), fsync(3C), attributes(5), standards(5) SunOS 5.11 5 Jul 1990 sync(2)

Check Out this Related Man Page

SYNC(2) 						     Linux Programmer's Manual							   SYNC(2)

NAME
sync - commit buffer cache to disk SYNOPSIS
#include <unistd.h> void sync(void); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sync(): _BSD_SOURCE || _XOPEN_SOURCE >= 500 DESCRIPTION
sync() first commits inodes to buffers, and then buffers to disk. ERRORS
This function is always successful. CONFORMING TO
SVr4, 4.3BSD, POSIX.1-2001. NOTES
Since glibc 2.2.2 the Linux prototype is as listed above, following the various standards. In libc4, libc5, and glibc up to 2.2.1 it was "int sync(void)", and sync() always returned 0. BUGS
According to the standard specification (e.g., POSIX.1-2001), sync() schedules the writes, but may return before the actual writing is done. However, since version 1.3.20 Linux does actually wait. (This still does not guarantee data integrity: modern disks have large caches.) SEE ALSO
bdflush(2), fdatasync(2), fsync(2), sync(8), update(8) COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2007-07-26 SYNC(2)
Man Page

15 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

How to place restrictions in a directory

I have a directory called sync and the directory path is ftp/exports/sync. What I would like to do is place some documents in sync for external users to view and would like to have access restriction for the sync directory. i.e. login and password. How do I go about doing this in a Unix enviorment.... (3 Replies)
Discussion started by: coburn
3 Replies

2. AIX

Wierd thing about FSs and VGs

Hello It appears that on a regular basis, perhaps when weekly rebooting happens, not sure yet, my odm becomes out of sync. When doing a smitty file system list by volume group, the FS type is displayed as ??? on several FSs. Always in the same VG. I know how to fix this problem, thing is,... (4 Replies)
Discussion started by: mhenryj
4 Replies

3. Linux

HELP PLEASE about Resync and sync interval in linux

Can anyone could tell me what is the meaning of this problem: Last successful check resync is greater than min sync interval (1195785433 > 7200) And what can do to solve this problem. Thank you..Please HElp me! (4 Replies)
Discussion started by: o_m_g
4 Replies

4. UNIX for Advanced & Expert Users

how to sync remote folders without overwriting

Hi, I need to sync 2 remote folders so i setup with rsync which is working very fine. But, there comes another requirement to maintain multiple versions of files on destination (NOT to overwrite the destination file). If there is difference between source file and destination file, it must... (2 Replies)
Discussion started by: prvnrk
2 Replies

5. UNIX for Advanced & Expert Users

Does sync(2) block writes until completed?

Gentle readers, I am trying to observe system behavior on our RHEL 5.2 machines. I notice that, it appears to me, based on random iterations of dd if=/dev/zero of=/var/tmp/bigfile bs=1024 count=20000 ...that if the pdflush is flushing buffers at the time of my write, my write will take... (4 Replies)
Discussion started by: mschwage
4 Replies

6. Shell Programming and Scripting

sync files from two different servers.

I have a directory called UNIX 1 which contains 2 files and uploaded into two different servers. Now I want to check whether the directory contains both the files. If not, then need to sync the directory. Please let me know how to do that in shell scripting. (2 Replies)
Discussion started by: madan1
2 Replies

7. Shell Programming and Scripting

Password script sync

Hi all, I am trying to create a simple password script but it seems not working well. What I'm trying to do is to sync the yppasswd and smbpasswd. So I created this: #!/bin/csh echo "" echo "Please enter old password: " set OLDPASSWD = $< echo "Please enter new password: " set NEWPASSWD... (2 Replies)
Discussion started by: saiful
2 Replies

8. UNIX for Advanced & Expert Users

drbd8 skip initial disk sync?

Anyone know how to go about skipping the initial disk sync of a newly created drbd resource? I'm creating brand new 30gb partitions and would like to skip the entire initial sync, I've read this is possible but I cannot seem to find the instructions to do it. Thanks, Trey (2 Replies)
Discussion started by: trey85stang
2 Replies

9. UNIX for Advanced & Expert Users

How to Sync two servers

Hi All, want to sync. two servers , both are having solaris os. If am updating any thing in one server , it will automatically sync. with the other server . Is it possible , if so den how ? (3 Replies)
Discussion started by: natraj005
3 Replies

10. UNIX for Dummies Questions & Answers

Having a problem with the time sync from Solaris 10 to VirtualBox

I have a VirtualBox w2008r2 Domain Controller running on a Solaris 10 server. I have the time on the Virtual machine set to Default time sync (bios clock) and the Solaris server set to sync to 0 8,20 * * * /usr/sbin/ntpdate tick.usno.navy.mil tock.usno.navy.mil >> /tmp/ntp.log My problem is... (2 Replies)
Discussion started by: SIFT3R
2 Replies

11. Red Hat

Best way to sync time on a Linux machine

I wanted to know which should be the best way to sync time for a linux machine. We have an application server and a database server, both using RHEL 5.8 as the OS. It is important that the time on both these servers match together and also sync with a common time source. As per my knowledge, these... (11 Replies)
Discussion started by: RHCE
11 Replies

12. UNIX for Advanced & Expert Users

Faster dd for disk clone

Guys can anyone tell how can we do faster disk cloning Below i found in google 1. dd if=/dev/sda of=/dev/sdb bs=4096 conv=noerror,sync So adding "conv=noerror,sync " makes it faster looks against not adding it 2. Enable write cache activated (hdparm -W1 /dev/sda) then run dd .. ... (2 Replies)
Discussion started by: heman96
2 Replies

13. Shell Programming and Scripting

How can we automaitcally sync/copy files from one directoy to another ?

Hi, I would like to achieve below requirement, I have a directory "/mydir" and I want to automatically sync/copy all the content of /mydir directory to "/yourdir" directory all the time. meaning, if some application creates a file in /mydir, it supposed to be copied/available in "/yourdir"... (4 Replies)
Discussion started by: aaron8667
4 Replies

14. Red Hat

How to sync time with bios in rhel7?

Hi All, I deployed the rhel7 server in the bare metal hardware. I want to configure the rhel7 server to sync time with bios. I tired the below commands. Still it did not sync the time with bios. Thanks, Kalai (3 Replies)
Discussion started by: kalpeer
3 Replies

15. UNIX for Beginners Questions & Answers

Need little help in understanding UNIX file system.

statement 1 : I see everyone saying Unix follows a tree like hierarchial structure. Statement 2: Unix file system has four blocks 1.boot block 2.super block 3.inodes 4.data block My question is , in which of the above four blocks , the hierarchial structure comes.?? How could we corelate... (2 Replies)
Discussion started by: Narendra Eliset
2 Replies