This is undoubtedly an upstream issue, but ...
I've been messing about with that hp pavilion trying to get wireless working. If I boot with the eth0 NIC plugged in, everything is blazingly fast -- GDM comes up in a few seconds, the Gnome startup splash screen barely has time to appear before it's gone again, shells pop up the instant I click Open Terminal.
If I unplug the network and reboot, it all goes to hell. It takes several minutes for GDM to start, the splash screen sometimes lingers up to 10 minutes after the window manager is running, terminal windows take varying lengths of time from 2-15 minutes to open. It even takes 5-6 minutes to mount filesystems from the USB drive.
Nothing unusual appears in "top"; gnome-system-monitor is one of the apps that takes forever to launch (to the point that I thought it had crashed), but it doesn't show anything odd either. No activity in the various /var/log files. Any ideas what could be causing this?
Sounds like DNS.
At a guess, I would try adding your hostname to the /etc/hosts file and set either a permanent IP address, or use 127.0.0.1
John.
Bart Schaefer wrote:
This is undoubtedly an upstream issue, but ...
I've been messing about with that hp pavilion trying to get wireless working. If I boot with the eth0 NIC plugged in, everything is blazingly fast -- GDM comes up in a few seconds, the Gnome startup splash screen barely has time to appear before it's gone again, shells pop up the instant I click Open Terminal.
If I unplug the network and reboot, it all goes to hell. It takes several minutes for GDM to start, the splash screen sometimes lingers up to 10 minutes after the window manager is running, terminal windows take varying lengths of time from 2-15 minutes to open. It even takes 5-6 minutes to mount filesystems from the USB drive.
Nothing unusual appears in "top"; gnome-system-monitor is one of the apps that takes forever to launch (to the point that I thought it had crashed), but it doesn't show anything odd either. No activity in the various /var/log files. Any ideas what could be causing this? _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
John Newbigin ha scritto:
Sounds like DNS.
At a guess, I would try adding your hostname to the /etc/hosts file and set either a permanent IP address, or use 127.0.0.1
John.
I agree with John: the communications between the server and the client under X are trying to resolve the hostname which fails and they have to wait for the DNS query timeout.
The solution is to put the hostname on the 127.0.0.1 line in /etc/hosts If you want to be able to call the "official" address, put the full hostname.domain on a separate line on /etc/hosts
I feel my english writing skills not adequate, so I write an example to explain better:
/etc/hosts:
# Do not remove the following line, or various programs # that require network functionality will fail. 127.0.0.1 linux localhost.localdomain localhost 192.168.0.1 linux.mydomain.com
so if I ping linux I ping the loopback address; if I ping linux.mydomain.com I ping the ethernet address.
As I know GDM and X uses the short name, hence the "trick": even if the ethernet cable is unplugged (and 192.168.0.1 doesn't exists) all is fast and working.
Bye
Lorenzo
On 5/11/07, Lorenzo lorenzo@gmk.it wrote:
I agree with John: the communications between the server and the client under X are trying to resolve the hostname which fails and they have to wait for the DNS query timeout.
I'm willing to believe that (and will edit /etc/hosts as soon as I next boot the laptop) but why would DNS have an effect on speed of access to USB disk drives? It takes extra time to mount them even from a text console when the machine is in this condition.
Bart,
I know it sounds strange, but.. ¿Do you use the ntpd service? ¿Is it active?
On 5/11/07, Jordi Espasa Clofent sistemes.llistes@intergrid.cat wrote:
I know it sounds strange, but.. ¿Do you use the ntpd service? ¿Is it active?
Yes, and yes.
I know it sounds strange, but.. ¿Do you use the ntpd service? ¿Is it active?
Yes, and yes.
It's the problem. I don't know why, but if the ntpd service is active and, in the boot process the network is unavailable you'll suffer this lack of time.
Making a definitive test is simple: deactive the ntpd service, take off the wireless NIC and reboot the system. If the next boot has the "normal" speed, you already know what is happens.
I wait you comments about.
On 5/12/07, Jordi Espasa Clofent sistemes.llistes@intergrid.cat wrote:
Making a definitive test is simple: deactive the ntpd service, take off the wireless NIC and reboot the system. If the next boot has the "normal" speed, you already know what is happens.
It does not seem to be related to ntpd -- or else ntpd is happy with the addition of the hostname to /etc/hosts.
Something -- I didn't do it directly -- had already added the hostname to the 127.0.0.1 line in /etc/hosts by the time I got around to looking there. I don't know whether it was there before or not, nor what I did (boot with the wired network plugged in? Download updates? The timestamp on /etc/hosts changes every time I reboot, so something is updating it). In any case it was not necessary to disable wireless or deactivate ntpd to get normal response back.
At the same time, if I do anything that requires DNS (like try to ssh to a remote host), all the symptoms return until the DNS query times out, at which point all is well again. So it is DNs's "fault" somehow. (Interestingly, even though some warnings from ntpd about unreachable time servers show up in /var/log/messages, they don't seem to induce this problem.)
It does not seem to be related to ntpd -- or else ntpd is happy with the addition of the hostname to /etc/hosts.
Ok. However, the test has been exitous: you know what is NOT problematic. This fact reduces the problem.
Something -- I didn't do it directly -- had already added the hostname to the 127.0.0.1 line in /etc/hosts by the time I got around to looking there. I don't know whether it was there before or not, nor what I did (boot with the wired network plugged in? Download updates? The timestamp on /etc/hosts changes every time I reboot, so something is updating it). In any case it was not necessary to disable wireless or deactivate ntpd to get normal response back.
Ok.
At the same time, if I do anything that requires DNS (like try to ssh to a remote host), all the symptoms return until the DNS query times out, at which point all is well again. So it is DNs's "fault" somehow. (Interestingly, even though some warnings from ntpd about unreachable time servers show up in /var/log/messages, they don't seem to induce this problem.)
What a curious problem! You can enable a tcpdump sniffer and put here the output you'll get. More useful and easy instructions at: http://www.freesoft.org/CIE/Topics/55.htm
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Bart Schaefer -
John Newbigin -
Jordi Espasa Clofent -
Lorenzo