Trying to debug a network issue - we have problems with scp transfers to a remote host intermittently stalling. I believe it may have something to do with incorrect handling of sack / dsack TCP options. Looking at netstat -s, during a (successful) scp transfer the TCPSACKDiscard and TCPDSACKIgnoredNoUndo counters increase rapidly. This is on the client initiating the transfer to the remote server. This doesn't seem normal, but I'm having difficulty finding an explanation of what exactly these counters signify. The tcp_sack / tcp_dsack / tcp_fack options are enabled in the kernel on both hosts.
How do I debug this further? Are the counters a symptom of a known problem? It's kind of hard to google this, all I get is unrelated netstat output which happens to include 1 or 2 discarded SACKs, not tens of thousands like I am seeing. I can make tcpdumps on the client (unfortunately not the server), but what should I look for?
i have searched the forum but can't find the solution for stalling network in the middle of something. i have to restart the computer. i cannot rely ubuntu for 24 hours non-stop small server. the stalling problem occurs when I start pulling/downloading via samba or sftp (smb:// or sftp://) from another computers/device (like wdtv). when i check the lenovo, all internet connecetion is dead. ifconfig shows the ip but it just dead.
After deleting part of the gnome config directories in order to reset gnome (GUI was messed up - No title bars, etc). I lost my bluetooth tethering to my Nokia N900. I cannot redo it as it always fails. Linking from phone to Laptop works, but cannot use it to link up to the internet then. Cable to the phone always worked up till now. Now I cannot get a connection as it stopped working after my upgrade to 11.04.
I'm surfing along just fine when I select some link in my browser.The status line reports "... waiting for ..." and the browser seems to stall for a long time (minutes). Often, but not every time, I can select the STOP toolbar icon and reload the page. This time things work normally.
I have a similar but different malfunction running Evolution email connected to my hosted IMAP server. I select a message and see "... formatting ..." and then Evolution seems to stall for a long time (minutes). Rarely the stop-reload actions help reading email. Instead,all Evolution windows go dark grey and the entire desktop stalls.[Analysis -- It has the feel of a "network" issue provoking issues within Evolution itself rather than an Evolution-only malfunction.]
Watching the running system with 'htop' and similar, I do not see where some other application or service is sucking all of the available CPU time or such. [Analysis -- It has the feel that either the browser message or the email message were sent into limbo without reaching their intended destination. Stop-reload sends the bits to the right places and so I get results.]
I like to watch DVD's from netflix etc on my laptop. I've tried VLC, Mplayer, Movie Player and Xine and all of them do the same thing more or less. The movie plays but it pauses or lags every 3-6 minutes or so, then resumes. VLC seems to work the best, but it does it too and it's to the point where it is irritating to watch a movie on it. You watch 10 minutes, then a freeze, VLC says "buffer.." and runs from 0-100% in a little progress bar, the DVD drive spins up again furiously then the movie plays again. Over and over through the whole movie.
It does it in EVERY DVD I have tried. I've tried everything from completely uninstalling the movie players, reinstalling them, tweaking every setting I can find per instructions I've found on other forums. I even went as far as going into my laptops BIOS to set the CD drive speed to HIGH.
Is this just how it is watching a DVD on Ubuntu or what? I really do NOT want to resort to reinstalling Windows 7 (ugh) but this is unacceptable. I'm open to any and all suggestions on how to get acceptable, reliable performance out of one of these DVD apps. Not sure what info will be relevant but, the machine is a brand new Lenovo T510 thinkpad, Core i5 2.4 ghz, 4 gb RAM, Nvidia graphics. Running Ubuntu 10.04 32 bit.
I've seen packets coming to my computer through a DD-WRTv24s2 gateway above port 32K several times. I have iptables (using fwbuilder locally) both places. My desktop stops the packets. But I'm guessing the problem is as I described in the title for this post. Yes?If you ESTABLISH a connection to some webpage, and you just accept ESTABLISHED or RELATED datagrams in rule 1 of your iptables, what will keep incoming TCP from that (presumably nefarious) site from going straight to your desktop like the building firewall isn't there?? If the site wants to connect to you above 32k, or portscan you, its RELATED correct? They know your IP. You've ESTABLISHED a connection.If my guess is correct, it would seem wiser to NEVER use these together. Better to ACCEPT all ESTABLISHED. And if something is RELATED, then ACCEPT it only if its the data connection on FTP or individually by service or protocol.
this is scary, bunch of vmware-user-wra processes stall cpu 100%!! What's going on? Server has just been restarted! Bere I restarted, the root started all this vmware-user-wra!! I was configuring vncserver! After restart, it's started by user roo300 which I have used to login via SecureShell!
There is a major problem - networking does not work at all for me in this setup with the new kernel.I use Debian distro on this notebook.I don't have previous experience with submitting a kernel bug and would like to learn how to do it to be able to help the community. There is a tool called reportbug in debian, but it is too much automated, I think - it automatically fills in the kernel version I booted to right now, but I need to report bug to different kernel version, in which networking does not work
Brand new network, just installed, all ubuntu 9.10 boxes connected to a Dell 2206 dumb gigabit switch, and from there to Dlink router to cable modem. Pretty simple. ISP confirms great link out and inbound,
However, http requests can sit for 20-30 seconds (sometimes longer), before content returns, same for pings.
Some thought it might be MTU-related. What is best MTU setting 1500/1492/ ?
I've only used Linux for about a year or two now and have worked through suspend esume and WPA wireless issues with CentOS and my T61p. However, I'm stumped on this one. why my T61p freezes randomly (happened once while writing this topic) with the caps lock light blinking. I'm wondering if it has something to do with my nVidia driversettings andor using my wireless card and/or switching between home wwireless and work wwired connection.
I have a relatively new server (Ubuntu Server 10.04.1) with a "/backup" partition on top of LVM on top of an MD raid 1.Everything generally works, except that it freezes during the fsck phase of bootup, with no errors. I've given it 20 minutes or so. If I press 's' to skip an unavailable mount (documented here), it reports that /backup could not be mounted.here are no LVM related messages in /var/log/messages, syslog, or dmesg.
When I try to mount /backup manually, it reports that the device (/dev/vg0/store) does not exist. Apparently the volume group was never activated, though all documentation seems to claim it should happen automatically at boot. When I run "vgchange vg0 -a y", it activates the volume group with no issue, and then I can mount /backup./etc/lvm/lvm.conf is unchanged from the defaults. I've seen posts mentioning the existence of a /etc/udev/rules.d/85-lvm2.rules , but no such file exists on my server, and I'm not sure how I would go about creating it manually, or forcing udev to create one.There are some open bugs describing similar problems, but surely it doesn't happen to everyone or there'd be many more[URL]
I tried the Googles praised Chromium browser and while it seems to render pages fast enough and has a really nice interface, I experienced an annoying responsiveness problem. Opening a link in a background tab seems to stall the browser almost completely until the page has been loaded and rendered. For example scrolling the page that I'm currently viewing becomes almost impossible. The same actually applies to the current tab too, of course. If the page in the tab hasn't been loaded completely, scrolling is really really clumsy. I tried disabling the installed extensions and also tried experimenting with some command line options, but no help there.
I got this definition:"a process that replaces a series of related, specific routes in a route table with a more generic route." honestly I found it not so clear.. I want to know if this definition is correct and also more details about this subject..
I am running a Debian server, with 2.6.30 kernel and everything standard.I have two ethernet cards (eth1 is the external, eth0 the internal) and I use the server as backup server, firewall, https for email reading with squirrelmail, Samba server, email server and that's it.If I understood correctly IPTABLES, the following OUTPUT rules should allow my server to establish communications with an http server (for dselect), an imaps server (for fetchmail) and an ssh server.However, it does not work, it only works when I allow all OUTPUT (adding "NEW" to "ESTABLISHED,RELATED")).Could anyone let me know what is wrong and how I can fix it (not opening my OUTPUT to any communication)?My IPTABLES script is pretty long, so I only copy/paste the OUTPUT lines unless anyone requests the rest.uote:
Having some trouble with a new install of Ubuntu 11.04. I use it for work, so I do tend to run quite a few programs at a time. Namely Pidgin, Firefox, Thunderbird, Chrome, Osmo, LibreOffice Calc, Calculator and Text Editor. Sometimes I'll listen to music using VLC. Sometimes (and I can't figure out when), I will be suddenly logged out without warning. Just BAM, black screen then back to the login screen. I've lost work from this happening.
My only clue is that it hasn't happened when I was not running VLC, but then again it doesn't happen consistently while running VLC. Also, it happened today when I wasn't running VLC but was using Calibre (along with my usual programs). Maybe I'm doing too much at one time? Maybe it's the RAM? How do I view an error log about what happened?
I want some users should be barred from login into some of NIS clients. Please help me to accomplish this. I googled it but still not very clear to me. Can you please tell me how it works. The OS is RHEL 5.
I am using KMS with a radeon 3650, KMS with kernel 2.6.33.2, xf86-video-ati 6.13.0 and mesa 7.7I am using fluxbox, and only have one transparent terminal running. I have not been playing any games(so no 3d acceleration?).My computer is getting far too hot from this. Not overheating to the point it shuts down, but the fan is going full bore, and mplayer stutters when playing a movie.This never happened when I was not using KMS, so it seems likely that that is the cause. It is definitely related to graphics, because when I exit X the temperature cools rapidly.Is this just because KMS is new and still being worked out, or is it something that can possibly be fixed?
how, and if, I enable 3Dnow, and other CPU related features?
I'm not having any problems or anything to that effect. I am only curious. Is this something that's automatically done? Is this something I must do during compile and install of applications?
haunted@haunted-desktop:~$ sudo grep flags /proc/cpuinfo flags: fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36 mmx fxsr syscall mmxext 3dnowext 3dnow
If this is something I must enable manually per application, then for example, if I wanted it enabled for FlightGear, how would I go about doing that?
I just blindly install 'java' in GNU/Linux Debian SID -- so I could use it as a plugin for iceweasel -- Unfortunately, things didn't work as expected. I was used to Debian's APT to take care of things for me as it had done for more years than I could remember. (Being a desktop user/programmer and a beginner system network admin). I want a clean install of java plugin for iceweasel. So I want to remove completely all java related packages --
How do I know which is which and if they are safe to remove without affecting any other part of the system? Now, to install -- what do I need to install in order for iceweasel to have the Java plugin and let java work as it should? I prefer from the Debian package. But if it doesn't work, I'll accept JRE from the java site and install them myself.
In the processing of reinstalling VirtualBox, I found this：2.6.35.6-48.fc14.i686.PAE/source -> /usr/src/kernels/2.6.35.6-48.fc14.i686.PAE/ ，but this folder don't exist.。 I try to relink the ln as source -> /usr/src/kernels/2.6.35.9-64.fc14.i686.PAE , but VirtualBox still get problem with the kernel. Since VirB works fine with other 2 kernels, the solution for this is not quite needed, but I just wonder why this happens. See below. I don't know why these two folder contain different version of kernels. Anybody get an idea?
2.6.35.6-48.fc14.i686.PAE]$ ll /usr/src/kernels/; ll /lib/modules/; ll /lib/modules/2.6.35.6-48.fc14.i686.PAE/ |grep build total 16 drwxr-xr-x. 22 root root 4096 Nov 19 14:58 2.6.35.6-45.fc14.i686 drwxr-xr-x. 22 root root 4096 Nov 15 00:04 2.6.35.6-48.fc14.i686 drwxr-xr-x. 22 root root 4096 Dec 8 17:08 2.6.35.9-64.fc14.i686 drwxr-xr-x. 22 root root 4096 Dec 8 15:19 2.6.35.9-64.fc14.i686.PAE
11.3 installation appears to be completely unusable for mission critical workit's running/freezing on a Toshiba a300 laptop, intel 965gm gfx, using the drivers that where installed by 11.3whenever the unstoppable screen/monitor saver kicks in, it freezes the machine irrecoverably.same as: 11.3 kde constant lock upsthe unstoppable screen/monitor saver has been a pain in the neck in 11.2 too, is it possible to COMPLETELY REMOVE any code that will make the gfx go on standby? what a pain when you are watching a movie! disabling everything obvious never worked! wtf?
I know 10.3 is old, but my main reason for using Linux is that I can build a machine and then just use it for 3-5 years without dealing with stupid degradation issues like Winblows.
The problem is that I can't access any 10.3 online respositories anymore, so package management is a big mess. Basically I'm down to manual rpm-ing. If I try to install anything with Yast, it attempts to access 10 different repositories for dependencies, all of which fail because I guess they just don't have 10.3 directories anymore.
I really hate updating my Linux all the time to the newest version, because frankly that usually breaks things.
Not sure what do to. This conundrum often makes me consider if any distributions are better in this regard. But then I don't have a lot of time to play with Linux. What started out as a hobby in 1994 is now a tool, like any OS, that I just want to work. I don't use Linux to use Linux, I use it to run programs.
I am trying to add subdomains on ubuntu 9.10 desktop edition and and I am not sure whether I need to add some info.(such as 127.0.0.1 sub1.example.com and so on) to the /etc/hosts file like the windows' windows/system32/drivers/etc/hosts file. I used to use the wamp-server(on Windows 7), I needed to edit 3 files, httpd.conf, httpd-vhosts.conf and hosts. And almost every edit is made in the httpd-vhosts.conf file on wamp-serveriles should be edited? or what else should be done that I didn't mention?
I installed Mono 2.4 and I am struggling myself to remove all folders related to mono.. I didn't install from Synaptic so it's not just 'apt-get autoremove mono', I used the tarball.. how to remove all files from the installation?
I've had my share of troubles with Ubuntu before and always been able to find help just by reading the forums, but this time it doesn't seem to be happening. Basically, I think I did something stupid by trying to change the permissions on my home folder to 777. (I'm the only person who uses my computer and got sick of always having to get root permissions.) Halfway through the process, the computer slowed to a crawl and text in dialog boxes started getting replaced with empty squares.
Naturally I rebooted - or tried to. Regular boot didn't work, so I tried recovery mode, which was kind enough to tell me I had a kernel panic because sbin/init wasn't found. Here's where things got weird: I then tried to boot from my Ubuntu USB stick, and couldn't. I got to the USB menu, hit the "run" option, and after a few seconds of the Ubuntu boot screen, my monitor went blank. Actually, to be technical, it didn't just show a black screen - the screen shut off. That's as far as I've been able to get.
By the way, just before I tried what I'm now calling the chmod-of-death, I also had an update freeze in the middle. I am able to boot into Windows, and have checked my USB stick - all seems fine. Any thoughts on this? Worst case, I can reformat the partition and reinstall, but I'd rather not lose all that data.
UPDATE: Okay, so I *did* manage, after about ten more tries, to boot from the USB stick. I went in from there and changed all the permissions back to 755. Tried to boot in recovery again, and still getting the same sbin/init error - so I'm wondering now if it had more to do with the failed update than the permission change....
I installed FC14. But when i create a VPN connection using NetworkManager, 10 seconds after VPN connection was established, vpn connection has been disconnected.In FC13, I didn't have this problem. In FC14, i use same settings used in FC13.
After building a new system I have been getting kernel panics randomly. I have been able to look at /var/log/messages and determine that either my RAID card, XFS, or something along those lines is causing the problem. It has now gotten bad enough that any heavy use of the RAID will cause it to panic and die.
There is one large file on this that I need which is not on my backups but when I try to get it off, the transfer will cause a kernel panic within minutes. What is causing the panic? Is there any way to resolve it? The RAID card is an LSI SAS3081E-R and I am using the built in drivers/modules within Ubuntu 10.04 x64 (pretty sure the kernel itself has the driver included). There is source available for the driver from LSI's site but I'm not sure if that will solve the problem and in addition to that, I can't figure out how to compile and install it. It has a Makefile already but make just complains "no targets".
Code: Jun 21 13:00:22 cyan kernel: [ 706.206498] ffff88019652daf8 ffff88018ff61698 ffff8801935ddd50 ffffea00038f6650 Jun 21 13:00:22 cyan kernel: [ 706.206472] Process xfsdatad/2 (pid: 862, threadinfo ffff8801935dc000, task ffff88019652dac0)
