UPDATE(8) System Manager's Manual UPDATE(8)NAME
update - periodically update the super block
Update is a program that executes the sync(2) primitive every 30 seconds. This insures that the file system is fairly up to date in case
of a crash. This command should not be executed directly, but should be executed out of the initialization shell command file.
SEE ALSO sync(2), sync(8), init(8), rc(8)BUGS
With update running, if the CPU is halted just as the sync is executed, a file system can be damaged. This is partially due to DEC hard-
ware that writes zeros when NPR requests fail. A fix would be to have sync(8) temporarily increment the system time by at least 30 seconds
to trigger the execution of update. This would give 30 seconds grace to halt the CPU.
7th Edition November 17, 1996 UPDATE(8)
Check Out this Related Man Page
SYNC(8) System Manager's Manual SYNC(8)NAME
sync - synchronize data on disk with memory
sync [--help] [--version]
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 manner (e.g., before causing a kernel panic when debugging new kernel
code). In general, the processor should be halted using the shutdown(8) or reboot(8) or halt(8) commands, which will attempt to put the
system in a quiescent state before calling sync(2). (Various implementations 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.
Print version information on standard output, then exit successfully.
-- Terminate option list.
The variables LANG, LC_ALL, LC_CTYPE, and LC_MESSAGES have the usual meaning.
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. Mail corrections and additions to
email@example.com. Report bugs in the program to firstname.lastname@example.org.
SEE ALSO sync(2), halt(8), reboot(8), update(8)GNU fileutils 4.0 1998-11 SYNC(8)
I have followed instructions to get the jdk for sparc, 1.3 loaded on this sparc workstation machine. I used a tar file and everything seemed to go fine. The usr/j2se directory was created with all the subdirectories and java files. However, attempting to run Java commands fails with a file not... (18 Replies)
I am trying to update a MASTER file by a NEW file which may contain fewer records.
The update should use a key (2 first fields), here is a senario:
the result should be:
can you recommend me a way to do it?
Y.N. (25 Replies)
Hello, i am bit stuck with making script for automatic procedure.
Two files. One is flat file, other is csv file.
csv file has two column/fields with comma delimited data.
Here is what i need (explained way)
field1 | field2
"hello2","byebye2"... (23 Replies)
I am writing a software product and hope that it will work on a variety of Linux distributions. At the moment, I am trying to create some kind of Linux version of patches/upgrades of installed software. Gathering information on available updates isn't hard, nor is installation of updates, but I... (27 Replies)
I am running on Ubuntu 12 (precise) 64 bit and came to know that i cannot install any packages using apt-get and aptitude.
Linux test01 3.5.0-23-generic #35~precise1-Ubuntu SMP Fri Jan 25 17:13:26 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
But the same /etc/apt/sources.list file is... (20 Replies)
I have a sun v880 that i got from ebay for cheap as a way to to learn Solaris and sun hardware in general.
The machine currently has OBP 4.7.0 2002/10/25 and i was wondering if there was a way to update the prom with out and active solaris install, as currently when i proceed with the... (29 Replies)
I'm completely new to bash scripting and still learning my way through albeit vey slowly.
I need to know where to insert my server names', my ip address numbers through out the script alas to no avail.
I'm also searching on how to save .sh (bash shell) script properly.... (25 Replies)
I am trying to match $1 in file1 with $2 in file2. If a match is found then $3 and $4 of file2 are copied to file1. Both files are tab-delimeted and I am getting a syntax error and would also like to update file1 in-place without creating a new file, but am not sure how. Thank you :).
... (19 Replies)
I have a listfile contains list of files path.
i need to read the line of the listfile
mv the file to other directory
and update the listfile by deleting the lines of the listfile.
while read -r line || ];
mv $line... (19 Replies)
I moved the user information in the top right on the navbar to side panel and replace it with a clickable avatar image. If you have an avatar, you will see your avatar and if you don't you will see some default one (will change it to something better later).
If you have any notification... (53 Replies)
Upgrade (step 1) the posts, by putting a "user info" icon in the top right and making it so it toggles the user info.
The user info icon has a badge which shows the number of posts. I will have to dig around in the code more to get the total posts thanks and other badges working; but... (22 Replies)