Sponsored Content
Full Discussion: File Handles
Top Forums UNIX for Advanced & Expert Users File Handles Post 5159 by Neo on Wednesday 8th of August 2001 08:11:16 AM
Old 08-08-2001
You mean 'file descriptors' (FDs) I think. The total number of FDs are kernel parameters. Depending on what UNIX flavor you are running, the kernel documentation and souce code has this info. Some systems are easier than other to reconfigure.

Also, there are formulas to change these parameters because raising or lowering one key kernel parameter effects others (like a balance or scale.... commonly referred to as a design trade-off.)

So, as you know, you can't just make this parameter 100000000000 without seriously impacting (in a negative way) your system performance.
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

SSH in batch mode and File-Handles in a loop

Hi all I try to execute SSH commands on several hosts in a while-loop. There seems to be a problem with file-handle, first cycle works correct but no other one will follow due to the while condition is false even that there are many more host entries (lines) in all_hosts.dat. ... (3 Replies)
Discussion started by: DaveCutler
3 Replies

2. Shell Programming and Scripting

perl help with pipes and file handles (simple issue)

Hello, I have a program which opens a pipe for communication using file handle and forks 5 child processes. @waitlist = (1,2,3,4,5); foreach $item (@waitlist) { pipe *{$item},RETHAND; unless ($pid = fork()) { # Child process print RETHAND... (1 Reply)
Discussion started by: the_learner
1 Replies

3. Shell Programming and Scripting

How printf handles empty variables

See attached file that includes code, input and output. I am processing a colon delimited input file and building a ":" (colon) delimited output file. My printf statement prints contents of each of 20 variables and puts them into a record file. I am pushing out approximately 120 records. The... (2 Replies)
Discussion started by: Skyybugg
2 Replies

4. Shell Programming and Scripting

Monitor open file handles used by a process

We have a process that is running out of file handles. Is there some command line way to determine this that we can include into a cron script? Please let me know JAK (3 Replies)
Discussion started by: jakSun8
3 Replies

5. UNIX for Advanced & Expert Users

How UNIX/AIX handles a file deep down, say it's being read while another one tries to rename it?

Hi Thinkers, On AIX 5.3, we have a monitor program that reads the log file and searching for a certain string pattern that we define(say "transactionException"), if it sees it then it will raise an alert by sending an email. Because the log file XXX.log is rolling into XXX.log.0, XXX.log.1,... (2 Replies)
Discussion started by: TheGunMan
2 Replies

6. UNIX for Advanced & Expert Users

sendmails works, but opens 43 file handles per email -> problem

I'm using Sendmail 8.13.8 on a CentOS 5.5 vServer (Virtuozzo). I'm using a loop in PHP to send a lot of HTML-mails via sendmail. Each mail is a mail with individual statistics for our users, so its not mass mailing, bcc is not an option. It all works fine, but when I take a closer look there... (2 Replies)
Discussion started by: ZX81
2 Replies

7. UNIX for Dummies Questions & Answers

Script to leak file handles

This is a strange one. We have an issue where our system is leaking SCTP file handles. There are people working on this and in the mean time we have a monitoring script that alarms when we need to perform actions to manually clear them. For testing purposes I want to write a script that... (0 Replies)
Discussion started by: RECrerar
0 Replies

8. Shell Programming and Scripting

Match list of strings in File A and compare with File B, C and write to a output file in CSV format

Hi Friends, I'm a great fan of this forum... it has helped me tone my skills in shell scripting. I have a challenge here, which I'm sure you guys would help me in achieving... File A has a list of job ids and I need to compare this with the File B (*.log) and File C (extend *.log) and copy... (6 Replies)
Discussion started by: asnandhakumar
6 Replies

9. Linux

The Way Systemd Handles System Calls

Hi everyone, I have a question about the process management, and deep level system functionality of system calls between SystemD and SystemV? Does SystemD use the same system calls (fork(), exec(), bind() etc...) as SystemV? or Vice Versa? If they both use the same or very very similar sys... (2 Replies)
Discussion started by: Lost in Cyberia
2 Replies

10. Shell Programming and Scripting

Shell script (sh file) logic to compare contents of one file with another file and output to file

Shell script logic Hi I have 2 input files like with file 1 content as (file1) "BRGTEST-242" a.txt "BRGTEST-240" a.txt "BRGTEST-219" e.txt File 2 contents as fle(2) "BRGTEST-244" a.txt "BRGTEST-244" b.txt "BRGTEST-231" c.txt "BRGTEST-231" d.txt "BRGTEST-221" e.txt I want to get... (22 Replies)
Discussion started by: pottic
22 Replies
diskaudit_flush_interval(5)					File Formats Manual				       diskaudit_flush_interval(5)

NAME
diskaudit_flush_interval - determine time interval (in secs) for flushing audit records VALUES
Failsafe Default Allowed values Recommended values DESCRIPTION
The tunable controls the periodic interval between two consecutive flushes of audit records buffered in the kernel memory which is bound to a kernel thread. This kernel thread has 64KB of buffer size to hold the audit records, and there can be a maximum of 32 such threads. These kernel threads automatically flush their buffers if the buffers fill up completely, but that might take a long time depending upon the activities in the system. The value of the tunable should be set such that the threads keep cleaning their buffers when they are approximately half full, or are idle for a long time but still holding some data in the buffer. Keeping the tunable value too low will make threads flush too soon and may lead to too many small write operations, thus impacting performance. On the other hand, keeping the value too high might lead to high unflushed memory consumption. Who Is Expected to Change This Tunable? An administrator with proper privileges can change the value of Restrictions on Changing None. This tunable is dynamic. When Should the Value of This Tunable Be Raised? When the system is not processing many audit-related activities. What are the Side Effects of Raising the Value? If the system is generating large numbers of records, and the value is raised, then it can result in a lot of unflushed memory, and might slow down the system. When Should the Value of This Tunable Be Lowered? When the system is generating a lot of audit records. What are the Side Effects of Lowering the Value? If the system is not generating too many records, and the value is lowered, it might lead to a lot of small numbers of writes, which actu- ally only write to buffer cache and not immediately to the physical disk, with the actual write happening later on. This might impact per- formance again. What Other Tunable Values Should Be Changed at the Same Time? None. WARNINGS
All HP-UX kernel tunable parameters are release specific. This parameter may be removed or have its meaning changed in future releases of HP-UX. Installation of optional kernel software, from HP or other vendors, may cause changes to tunable parameter values. After installation, some tunable parameters may no longer be at the default or recommended values. For information about the effects of installation on tun- able values, consult the documentation for the kernel software being installed. For information about optional kernel software that was factory installed on your system, see at AUTHOR
was developed by HP. SEE ALSO
audit(5). Tunable Kernel Parameters diskaudit_flush_interval(5)
All times are GMT -4. The time now is 05:53 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy