CentOS 5 :: Purpose Of Fs.file-max In /etc/sysctl.conf?
Jul 29, 2010
On a production Centos 5.3 system, I want to raise the hard & soft limits of open file handles from 1024 -> 8192 (not a "biggie", I'd think) Right now, "sysctl -a | grep file" shows fs.file-max=463144 (a default, I'd guess) I'm guessing file-max is the maximum number of open file handles on the system, vs the per-user limits seen with "ulimit -Hn" and "ulimit -Sn". Right? If so, I shouldn't think I'd have to touch this on a server with few users.
Also, after doing a lot of reading, I still don't understand the mentions of needing to also add: "session required pam_limits.so" to /etc/pam.d/loginor adding "session required /lib/security/$ISA/pam_limits.so" to /etc/pam.d/system-auth Maybe I've gotten off into the deep weeds in goggling about raising file handle limits.
Due to a change in how programs in Linux are allowed to use memory, before using SheepShaver you need to set a variable in the file /etc/sysctl.conf Add this line: vm.mmap_min_addr = 0 but when i add the line in my text editor it says i cant save
My sysctl.conf in /etc isn't loaded at boot, it does however get parsed with the command # sysctl -p I believe this problem started when I got the 3.0.0 kernel just a few days ago. Does everyone has this problem? Then it's probably a bug.
I made some change to my sysctl.conf file and it they doesn't seem to load at boot? Each time I boot I need to send a sudo sysctl -p command to load the new parameter!
Last week I attempted to get "up to speed" with my Comcast cable connection... Ubuntu 9.10, Dell Vostro 400 desktop, Firefox 3.6.13... Comcast says I should have 12 Mbps connection... if I get 1.0 Mbps, I'm doing good... they just tested everything, and said everything is fine on their end. They use [URL] and connects to a server in Chicago, 60 miles away. That gets fantastic speeds, and it's a durn shame the internet doesn't store all its files there!! I use [URL] for my tests, and it uses a server in Dallas TX.
I go to my girlfriends house, and her AT&T DSL line has d/l speeds of 4.5 Mbps or better!!! She's running XP Pro on a Dell machine. So, started digging on the web and thru the forums, and found this:
[URL]
But, like ALL too many things, it's dated... it's from 2008... I've set my settings to what is there, and disabled ipv6 in Firefox. Hey, now, I'm sometimes up to 1.4 Mbps!! Also found this, but no date...
[URL]
Reading forums, I see that folks have said there is a network connection problem with 9.10... and then I see that others are saying the same thing about 10.04 and 10.10!! I have 10.10 on my laptop and had to fight to get its Atheos card to be recognized. Running some tests [URL] gives me weird results: Download 2.64 Mbps, Upload 4.12 Mbps. NOT what it should be. Similar results from testmy.net.
Dunno exactly what info is needed... Speedguide.net gives me results below, but I've tried changing numbers (says my RWIN is low) and nothing changes:
-------------------------------- TCP options string = 020405b40402080adf1dca100000000001030306 MTU = 1500 MTU is fully optimized for broadband.
[code]....
So, today, find, once again, that I'm d'ling in the range of 90/KB/s (719 Kbps)... disgustingly slow. I go on my HP laptop and run the test, and it says 1.6 Mbps. So, desktop directly connected to router is not even 1 Mbps, and wireless connection is faster? Neither of which is close to what I should be getting...
Does anybody have experience with linux tuning. I`m realy interesting about sysctl.conf tuning settings for batch(3d rendering, phisycs simulations, etc.) servers. Does anybody has an experience with linux tuning - I mean memory and CPU settings for heavy loaded systems. What kind of settings You have in Your clusters ? I`m working with Red Hat Enterprise 5 x86_64.
I am running an application that requires use of my /etc/hosts file. In it, I have my machine name and its LAN ip address. The program creates a service on a specific port, then attempts to connect to it based on the host name. So my hosts file has to be correct.I added the nameservers to resolv.conf and now my application will not run. My guess is that the computer is checking the name servers first, timing out then checking the hosts file.Is there a way I can tell the system to check the hosts file first, then DNS. I thought it should behave that way by default, but it does not appear to.
accidentally I do something wrong with my server and the httpd folder missing and I need it to setup my mail server and anyone can help me what can I do without reinstalling my Cent OS? Here is the error msg :
[root@mydomain etc]# service httpd stop Stopping httpd: [FAILED] [root@mydomain etc]# service httpd restart
I have just installed sendmailanalyzer to my centos 6 by using rpm package. But before, i tried to install it by perl.There is no problem now everything works but when i want to configure i see that there are lots of conf file. How can i see a conf file of service "sendmailanalyzer" what is the command ?
I have managed to delete my yum.conf file and do not have a backup. I have tried reinstalling yum and it does complete but when I try and run yum I get cannot find any conf file. Is there a standard conf file I can download? I am running centos 5.3.
today when i tried to login into another host my network using ssh it gave me an error saying that the remote host RSA key has changed and i should remove the file .ssh/<idon't rememeber> from my home directory for loggin in and it also gave me the warning that somebody is doing something nasty, As far as i remember we only reinstalled the system that ip, but then after deleting the file .ssh when i put the root password to that system it says bad password, What is an RSA key and what is its purpose under what circumstances is the RSA key gets changed, does it get changed after reinstallation what can do nasty that can change the RSA key
I've been scanning the apache2 docs for the past few days and have not come up with an answer my following issue:
In my httpd.conf file, at the very end, I have the line
Include conf/vhosts/vhost_*.conf
However, when I run apache checkconfig or try to start apache, it gives me the error:
httpd: Syntax error on line 993 of /etc/httpd/conf/httpd.conf: Could not open configuration file /etc/httpd/conf/vhosts/vhost_1.conf: Permission denied
It appears as if the Include line is correct - in terms of it grabbing the first virtual host conf file. However, I'm confused on the permissions. the /etc/httpd folder is owned by root:root, as are the subfolders. As a test, I chown'd the conf/vhost folder combination and all the vhost files to apache:apache to see if that made a difference, and it appeared to make no difference at all. The log files don't contain anything (assumed because apache isn't starting). If I place the contents of the vhosts in a singular vhosts.conf it works - with the permissions set to root:root. I'd like to avoid having to use one vhosts conf for the configuration I'm trying to achieve - as it would make my life a lot easier.
I attempted to run various cron jobs as root - just general server make-tidy stuff. But if I edit the /etc/crontab file directly, these tasks don't get run. However, if I use crontab -e as root, these jobs appear to work. Any idea why this might be the case? Also, I understand that user cron jobs are stored in /var/spool/cron/<user> (including root). If this is the case, what's the purpose of the /etc/crontab file?
I've just done a fresh install of Lubuntu 10.10 on an older Sony Vaio laptop. Having learned the hard way about editing xorg files, I wanted to create a backup of the xorg.conf file so that I dont have to do another install when I screw everything up. In a terminal, I typed
I've had Ubuntu 11.04 installed on my desktop since it's release. Up until an hour ago, it was working fine. I clicked on an update from the update manager, now booting into a graphical mode is completely broken, (the start-up load hangs at 'Check Battery State ... [0k]'). I restarted my computer, and booted into safe mode, and launched the terminal. This all works fine. I then typed :
Code: sudo gdm start into the command prompt, hoping that I would be able to start things manually. Instead, it spat out this: Code:
gdm-binary[230]: WARNING: Unable to load file '/etc/gdm/custom.conf'. No such file or directory. gdm-binary[230]: WARNING: Unable to find users : no seat-id found. gdm-binary[230]: WARNING: Gdm Display: display lasted 0.070467 seconds
The last line was printed about 8 times, with slightly different times, before it gave up and failed. Some information which might help, I have Gnome 2, Unity and KDE (not sure which version), installed. My graphics card is the GTX 275, and I have driver the Nvidia driver 275.21. So yeah, I think the update has gone and moved custom.conf somewhere, but I have no idea on how to fix it. I have a graphics programming assignment due on Friday and I would be eternally grateful if I could get this fixed well before then.
i am using ubuntu 9.10. i am trying to use ubuntu as a test bed for my thesis work on seamless mobility including SCTP and its add ip feature. i have installed lksctp with this command
sudo apt-get install lksctp-tools libsctp-dev
now i have to enable its addip feature and as i have read in other threads i have to change it from sysctl but the problem is that when i enter "sysctl -a" it does not show any sctp options.
How to back up my httpd.conf from my server to my computer and only found one solution via a google search
[url]
I typed in locate httpd.conf and see that it resides in /usr/local/apache/conf/httpd.conf so I assume I would type $ cd /usr/local/apache/conf $ sudo cp -p httpd.conf httpd.conf.bak
I wanted to confirm this with an expert before I do damage that I cannot reverse.
Using google with search option: cman not started: Can't find local node name in cluster.conf /usr/sbin/ cman_tool: aisexec daemon didn't start.I found this URL...I have found the config_version in cluster.conf. Unfortunately, as everyone may have noticed, english is not my native tongue so I am having trouble understanding the part "Make sure you bumped the cluster config version number". Can anyone enlightened me on what should I be doing so that I could "bump" the cluster config version?
If i type gedit while as root it give this warningQuote:(gedit:5655): EggSMClient-WARNING **: Failed to connect to the session manager: None of the authentication protocols specified are supportedGConf Error: Failed to contact configuration server; some possible causes are that you need to enable TCP/IP networking for ORBit, or you have stale NFS locks due to a system crash. See http://projects.gnome.org/gconf/ for information. (Details - 1: Failed to get connection to session: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.)And over the time, the paragraph block from GConf Error.... to ...was broken is repeated again and again
I am trying to follow the instructions in the smb.conf file which says, "name original file smb.conf.master and create the "real" config file with test parm -s smb.conf.master >smb.conf".
First I made myself the owner of the smb.conf file. Then I tried to rename the smb.conf file to smb.conf.master. When I try to do this with: rename smb.conf smb.conf.master the result is: Bareword "smb" not allowed while "strict subs" in use at (eval 1) line 1.Bareword "conf" not allowed while "strict subs" in use at (eval 1) line 1.
Can someone tell me what this means, (why it is happening) and what do I need to do in order to rename the smb.conf file to smb.conf.master.
I am not able to find /etc/resolve.conf on my centos machine.it says no such file or dir .with out this file i am not able to connect to internet.when i ping my localhost and my machines ip address i am getting a reply.but when i ping some domain(eg - google.com) i get no reply.i tried manually entering the dns nameserver from system->adminstration->network->dns tab.i dono what ip to enter there..
