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I'm reading Operating Systems in Depth by Thomas W. Doeppner, and I have a question about execl. He says it's called after fork(), and that it replaces the text (code) of the current process and replaces it with the code of the new program. But that doesn't make sense to me.
Does that mean... (4 Replies)
Discussion started by: SirSalt
When shutdown an oracle server i see this error message
umount: error unmounting /dev/oracle: Device busy
lsof and fuser report nothing
ps aux|grep oracle
oracle 5964026 0,0 0,0 448 448 - A apr 21 0:00 aioserver
oracle ... (16 Replies)
Discussion started by: Linusolaradm1
3. UNIX for Dummies Questions & Answers
Hello to all. I'm new to this forum, so please go easy on me. =)
I am working on a script to send two e-mail attachments in a single e-mail, and am running into a little bit of an issue when using process substitution. I am using the following:
cat <(uuencode $1 <(basename $1)) <(uuencode... (5 Replies)
Discussion started by: rommager
What is the recommended value for aioserver in aix 5.3
current value is 16384
And used is ps -k|wc -l 4768
We usauslly get issues like slow server performance and query waiting time more etc.
newaix (2 Replies)
Discussion started by: newaix
5. UNIX for Dummies Questions & Answers
So i did some research on the site but previous posts answered most of my questions about zombie processes but I have one question that didnt seem to get addressed
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I know p -kill doesnt always just... (6 Replies)
Discussion started by: kingpin007
I am an Oracle DBA with some strange IO performance problems.
Between 04:00 and 06:00 AM local time each day I see a degrading of
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I see that the AIX diagnostics seem to begin at 04:00.
Is it likely that AIX diagnostics might be affecting IO?
Additional... (2 Replies)
Discussion started by: sink
7. Shell Programming and Scripting
I have no idea how to do this:
Let's say the user opens an "xclock &" in one of my scripts and I don't want him to be able to re-open one with the script. How could I test that? Possibly with a message saying that "The <xclock(or w/e other process like xcalc)> is already running in the... (3 Replies)
Discussion started by: Yakuzan
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I have a file which contains 6 columns.
But I only need the first 3 columns. So I need to remove the last 3 columns. I checked 'cut' but it seems not working.
So is there a command that could remove certain columns from a file? :(
Thanks a lot!! (5 Replies)
Discussion started by: kaixinsjtu
9. UNIX for Dummies Questions & Answers
I know its kinda silly but I've seen the texts consider one side - a thread executes and finishes its task but I was wondering what will happen if the process dies when the thread is still under execution... I somehow think that the thread will continue execution but am backing off from the fact... (10 Replies)
Discussion started by: Legend986
I'm trying to understand how a parent and child processes interact.
This function( below) basically measures the fork time from the perspective of the parent only.
what i would like to know is how to measure the time from the perspective of parent and child (ie: inserting... (0 Replies)
Discussion started by: tosa
preap(1) User Commands preap(1)
preap - force a defunct process to be reaped by its parent
preap [-F] pid...
A defunct (or zombie) process is one whose exit status has yet to be reaped by its parent. The exit status is reaped by way of the
wait(3C), waitid(2), or waitpid(3C) system call. In the normal course of system operation, zombies can occur, but are typically short-
lived. This can happen if a parent exits without having reaped the exit status of some or all of its children. In that case, those children
are reparented to PID 1. See init(1M), which periodically reaps such processes.
An irresponsible parent process can not exit for a very long time and thus leave zombies on the system. Since the operating system destroys
nearly all components of a process before it becomes defunct, such defunct processes do not normally impact system operation. However, they
do consume a small amount of system memory.
preap forces the parent of the process specified by pid to waitid(3C) for pid, if pid represents a defunct process.
preap attempts to prevent the administrator from unwisely reaping a child process which might soon be reaped by the parent, if:
o The process is a child of init(1M).
o The parent process is stopped and might wait on the child when it is again allowed to run.
o The process has been defunct for less than one minute.
The following option is supported:
-F Forces the parent to reap the child, overriding safety checks.
The following operand is supported:
pid Process ID list.
Caution should be exercised when using the -F flag. Imposing two controlling processes on one victim process can lead to chaos. Safety is
assured only if the primary controlling process, typically a debugger, has stopped the victim process and the primary controlling process
is doing nothing at the moment of application of the proc tool in question.
The following exit values are returned by preap, which prints the exit status of each target process reaped:
0 Successfully operation.
non-zero Failure, such as no such process, permission denied, or invalid option.
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|Availability |SUNWesu (32-bit) |
| |SUNWesxu (64-bit) |
proc(1), init(1M), waitid(2), wait(3C), waitpid(3C), proc(4), attributes(5)
preap should be applied sparingly and only in situations in which the administrator or developer has confirmed that defunct processes are
not reaped by the parent process. Otherwise, applying preap can damage the parent process in unpredictable ways.
SunOS 5.11 19 Jun 2006 preap(1)