CentOS 5 Networking :: DNS Is SLOW After Enabling/disabling NetworkManager?
Mar 30, 2010
I ran into this today accidentally turned on networkmanager and it took it upon itself to rewrite some things and proceeded to make any DNS lookups on my server Especially those reverse DNS for SSH and SFTP take so long they would just time out instead of completing.. Disabling networkmanager did not undo the damage either. Short fix, Erase your resolv.conf file and add 2 lines to it as so, your nameservers!
nameserver xxx.xxx.xxx.xxx
nameserver yyy.yyy.yyy.yyy
save, and run the following commands
service network restart
service httpd restart
service sshd restart
Mine had a search line added by networkmanager and some others, when i reverted it back to as above, almost instantly after restarting the services the systems lookups were once again, lightning fast. DNS lookups were taking upwards of 20 seconds for unknown reasons after this happenned
I'm an inordinate amount of trouble getting F15 to run without NetworkManager. If I boot with the NetworkManager service enabled, my NIC presents as expected at /dev/eth0 (I'm using biosdevname=0). However, when I stop the NetworkManager service, /dev/eth0 disappears from the filesystem.If I boot without NetworkManager enabled, /dev/eth0 is never created. Reviewing dmesg, udev is loading an ethernet driver.
Is karmic is slower for you all: if you're running windows ping a server on windows/ubuntu and compare. 9.10 is consistently slower for me. I've seen enough "slow internet" posts to suspect that someone screwed up bad. Everyone says it's ipv6, but none of the fixes work for me. Pretty sure it's ipv6 (or at least a dns-related problem):
I have installed Ubuntu 10.10 on my laptop, and the internet was very slow and kept dropping in and out for any web browsers and sometimes the Ubuntu software center. After searching the internet for a while I came across several article saying to disable ipv6, which I have done, but the issue persists
I am having a problem using my laptop's special keys to toggle my touchpad on and off on my ASUS G73JH laptop, running Ubuntu 10.10 (2.6.35-28-generic-pae).
First, some preliminaries:
My touchpad works just fine, but it does not respond to my laptop's special key, Fn+F9.
In /etc/acpi/events I have the following script, "asus-touchpad":
Code: # /etc/acpi/events/asus-touchpad # This is called when the user presses the touchpad button and calls # /etc/acpi/asus-touchpad.sh for further processing.
How do you enable/disable the autostart of services. For example let's say I know I'm not gonna use apache and mysql for a while and don't want it to autostart anymore how do I disable it ?
And then once it is needed again how do you enable the autostart again ?
Trying to figure out why the following two are treated differently...
Code: *.warn; kern.!=debug;auth.none; authpriv.none;cron.none;mail.none;news.none -/var/log/syslog and
[Code]....
According to man syslog.conf "You can specify multiple facilities with the same priority pattern in one statement using the comma (``,'') operator. You may specify as much facilities as you want. Remember that only the facility part from such a statement is taken, a priority part would be skipped."
Can someone confirm that this statement means that kern.!=debug is ignored in the first part because it's priority is not the same as the trailing facilities ending in .none?
I'm running Centos 2.6.18-53.1.13.el5 in a VM. Currently I'm studying for my RHCT.I'm trying to enable IP forwarding so I edited this line in the /etc/sysctl.conf:
# Controls IP packet forwarding net.ipv4.ip_forward = 1 Then I ran sysctl -p
The resolv.conf is not written correctly every time i reboot the machine...it seems to ignore all sysconfig configurations !
this is the resoult resolv.conf after every reboot
# Generated by NetworkManager # No nameservers found; try putting DNS servers into your # ifcfg files in /etc/sysconfig/network-scripts like so: # # DNS1=xxx.xxx.xxx.xxx
I'm using CentOS 5.4. I want to set-up a PPTP connection (I'm the client). I installed the NM pptp plugin from EPEL's repository. I have configured my PPTP connection in the NetworkManager applet but now I don't know how to connect to the server, I mean, there's nothing like 'Connect now'.
I've been running CentOS on my laptop for a few weeks now. I don't know what happened today, but when I boot up, the NetworkManager wont show up on the panel, and I don't have access to wireless networks or Internet. I tried booting my Windows partition and the wireless works fine. I can't seem to remember any latest change I've made aside from the wallpaper =) Any ideas where I should start debugging? I could see the module "iwl3945" still loaded. Here's a manual type of my lsmod | grep iwl3945
I have a laptop with the radeon HD 5650 video card. I used ubuntu's hardware drivers program to install the official drivers, and it seems to be working well, including 3D acceleration in games. However, it seems that enabling compositing in KDE makes it much slower. For example, running glxgears without compositing gives me about 35000 frames in 5 seconds, after I enable compositing it's only 6000 frames. But it's not just glxgears, the slowness is very noticeable in games as well.
On my old computer, I had an nVidia card, and enabling compositing in KDE made it a little slower, but the difference definitely wasn't that huge. o_O Is it some wrong configuration, a bug in ATI's drivers, or something else?
I have an MSI K9A2 Platinum mobo, which has a 10/100/1000 Fast Ethernet Realtek 8111B built-in, a D-Link DIR-655 Router and a DSL modem. Compared to Windows Visya and other Linux distros ( Fedora 11, Suse 11.1, Mandriva 2009.1 ) access to the internet is much slower. It seems there is a noticeable delay when running CentOS 5.3. before internet access kicks in each time I am surfing the web or updating my system.
Is there any way I can speed things up, or determine why CentOS 5.3 seems much slower ?
I would like to enable XML-RPC module on my dedicated server with CentOs 2.2-3.2.el5 hosted on 1and1 server. How do I enable this module? What are the procedures?
I am having a problem with slow data transfers with both Samba and scp. I have gigabit NIC's on both all three machines that I am transferring to and from, connected to a gigabit switch. My data transfers under both smb and scp average around 21 MBit/s, (I am using nload to monitor transfer speeds).The machines are configured as follows,1) desktop
AMD Athlon 64 X2 6000+ 6 gig Corsair memory Realtek RTL8168C(P) gigabit NIC (on board)
I've just installed my first OpenLdap + TLS + Samba + Webmin box.Everything seems to work but when i try to open the Ldap User and group module from Webmin, it takes about 3 minutes but it works.When i use $ getent passwd or$ getent group.to see if everything works okay, it also takes ages but does not show my ldap users...Here's my spec
$ cat /proc/version Quote:Linux version 2.6.18-128.2.1.el5 (mockbuild@builder10.centos.org) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-44)) #1 SMP Tue Jul 14 06:36:37 EDT 2009
When running Firefox, page loading is very slow (e.g. taking nearly a minute for a ..... video to start; even gmail is slow). This is in contrast with my performance when using, e.g. linuxdcpp (file sharing), where I get speeds over 300kbps. Here is some relevant information:
I have a C application in which I was happily using stdint.h and other useful things like UINT32_MAX. Now, I am trying to move over to C++. Turns out, C++ does not support C99 and there is no equivalent header file (like climits for limits.h). So is there a way to enable C99 types in C++? Or any other equivalent header files?
I've run into this problem this week. The other night a power supply failed on a different system and appears to have surged the UPS which it and some other computers were plugged in to. One computer was fine, but the RAID server that is used for backups ended up with a bad disk and this "Disabling IRQ #169" message now shows up during boot, right after starting udev and setting the hostname. The system then sits there for 3-5 minutes before repeating a scroll of "/etc/rc.d/rc.sysinit: line 966: /bin/usleep: Input/output error"
I have booted with linux recovery from the CentOS DVD in order to replace the drive that was damaged. I rebuilt the raid array and all the data seems to be fine. There is another message though after "Red Hat nash version 5.1....." no raid disks and with names: "isw_bf jihdchhi_Hostname" failed to stat() /dev/mapper/isw_bf jihdchhi_Hostname
I was considering doing a complete reinstall of CentOS but if there is another solution I would much appreciate it, is it perhaps an issue with Grub not being able to find the updated array? As it is, it is impossible to boot the system except for using a live CD to do it.
New CentOS 5.4 system working fine. Sys admins came in and copied the hosts file from one of the servers down to my desktop and ever sincethen machine has been slow (progs take 10-20seconds to load). RunningGnome. Luckily I saved the old hosts file and copied it back and all is now well. But I'd like to understand why, particularly as I will need to change myhostname in the future.
As configured: /etc/hosts (yes my hostname is "dummyName" that I will need to change later) 127.0.0.1 dummyName localhost.localdomain localhost
I am trying to get VNC to work with display 0 on CentOS 5.2.In the past, I had always used the information straight from realvnc,URL... which is straighforward and simple, but this doesn't seem to work with CentOS 5. Once I attempt to connect to the server, it locks up.I have searched around and found the following info for CentOS 5, but I can't get it to work. The info seems very unclear and cumbersome to get display 0 configured.Has anyone gotten the RealVNC method to work on CentOS 5?
When i try to enable desktop effects on my dell inspiron 1440 running on CentOS 5.4 x86_64, this message is displayed:-'Desktop effects do not work with Xinerama'
I have a Centos NIS server that is working fine with other linux clients. i need to have a Solaris 8 client bind to the NIS domain and found out that Sol8 does not support MD5 format passwords that the NIS master is generating. so i am trying to disable the MD5 encryption on the nis master and it does not seem to work. i run this command
and it restarts portmap and nis services ok. on the master server i then do a yppasswd username and a make passwd and it still uses the 34 char password format. what do i need to do to disable MD5 passwords in a centos nis server?
I just installed CentOS 5.2 and then applied the updates to 5.3. Now I get repeated popups saying:
The NetworkManager applet could not find some required resources. It cannot continue.
I killed it and ran it from a terminal and saw the following output:
** (nm-applet:4648): WARNING **: Icon nm-device-wwan missing: Icon 'nm-device-wwan' not present in theme ** (nm-applet:4648): WARNING **: No connections defined
