[CentOS] Network Diagnostics
In our smallest office, we have a Dell CentOS 7 system, a Windows system and an HP 8610 printer, all hard-wire Ethernet connected with a Linksys router. The router provides Internet connection. All of the network-connected systems get their IP address from the router at power up. Successful network connection of the printer at power up has recently started taking much longer than usual. The display on the front of the printer indicates that it is initially attempting wireless connection even though this feature is turned off. Ethernet connection is eventually achieved and the printer functions normally on the network but just for a few minutes. After about five minutes, the printer drops its Ethernet connection and appears to be attempting wireless connection once again. During this period, network connectivity is disrupted for the other systems on the network. They are not able to communicate with each other or access the Internet through the router. Turning off the printer restores network connection for the other systems. One of our personnel at another office suggested using Wireshark to check out the network when the printer is having difficulty. Wireshark was apparently not on this system so we installed it using yum install. The tail end of the apparently successful installation process is shown below. Unfortunately, we cannot seem to find Wireshark on the system. Is it possible that Wireshark was not actually installed or do we just not know how to locate and use it? Is this printer networking issue a known problem and is Wireshark the right tool to diagnose the problem? Thanks. Installed: wireshark.x86_64 0:1.10.14-16.el7 Dependency Installed: libsmi.x86_64 0:0.4.8-13.el7 Complete! [user@computer ~]$ [user@computer ~]$ which wireshark /usr/bin/which: no wireshark in (/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:/home/user/.local/bin:/home/user/bin) [user@computer ~]$ Recent successful installations: [user@computer ~]$ [user@computer ~]$ which mplayer /usr/bin/mplayer [user@computer ~]$ which ffmpeg /usr/bin/ffmpeg [user@computer ~]$ ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
[CentOS] System Time
A few years ago, one of our interns was curious about system time keeping features in computer systems. This intern was also the proud owner of an inexpensive Radio-Controlled Clock. The intern wondered why computer motherboards were not just equipped with a chip like the ones in the RCC so that their system time would always be correct. I posted a question about this on the CentOS email list and received more responses than those postings about problems with the new Firefox release. I must have really struck a very sensitive system time nerve. This large response was a bit of a surprise and included a bunch of time related horror stories. It became clear why using an RCC chip on motherboards would NOT be a good idea. GPS network time servers seemed to be a preferred choice. All of our bedrooms have Radio-Controlled Clocks. At 5:30 this morning, half of the clocks displayed the correct time. The other half of the clocks were incorrectly showing a time one hour ahead. Maybe this is one more piece of evidence to reject using an RCC time base for computers, at lease in thestate of Arizona. ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
[CentOS] rpm command option
We located an application recommended by one of customers for sharing certain data. It was available for installation using a few different methods. Using yum was also recommended for the installation. The install instructions began with what appeared to be a fairly typical command as indicated below (with the URL slightly altered). sudo rpm --import https://rpm.x.com/rpmrepo.key To our junior employee assigned to perform the install on a test system, it seemed like a good idea to do some checking on the rpm option --import indicated in those instructions. They did not find the --import in any of the 14 pages of the CentOS 7 man page for rpm. Some Google searches indicated that the --import option does exist. The repo setup and application installation all went well and took only about three minutes. The app is also working as intended. Is there some good reason for --import being left out of the manual page? ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
[CentOS] Firefox Issue
We have several small networks, some of which have only four systems that are usually a mix of Windows 7 and CentOS 6 and CentOS 7 machines. All of these systems are Internet connected and updated regularly when yum finds packages available. Information about one of the CentOS 6 machines is included below. This system experienced a Firefox issue. [user@computer]$ uname -a Linux computer 2.6.32-754.3.5.el6.x86_64 #1 SMP Tue Aug 14 20:46:41 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux [user@computer]$ Several weeks ago, one of the Firefox updates did something unusual. It changed the browser-stored home page to https://www.centos.org/ from the original home page file:///usr/share/doc/HTML/index.html. This original home page had been in place since 2014, and had survived all Firefox updates for a little over four years. Last week, someone left one browser running and the system went into power save mode. To wake the system up we used the standard method of a quick push of the power button on the front of the Dell tower system. Although the system seemed to be running, the monitor and mouse never came to life. We also could not ssh into the system from any other computer on the network. We decided to use a steady push on the power button to shut the system down. After powering up again, the system seemed to run normally, but the browser home page was back to file:///usr/share/doc/HTML/index.html. Has anyone else experienced such an issue with Firefox recently? ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
[CentOS] Address Codes
One of our summer interns has stayed on during the school year to work some weekends on special assignments. This past weekend, her assignment was to draft, and try out, procedures for scanning all incoming regular mail including the envelopes. This is a new effort for us because previous mail handling was done by another organization. Most of our incoming mail is from other businesses that create printed address labels. Many of these labels also have a type of bar code below the address. Is there a Linux utility or standard application that will read and translate these codes. Thanks. ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
[CentOS] Firefox Video Capability
One of our summer interns has stayed on during the school year to work some weekends on special projects. This past weekend, her assignment was to trouble shoot problems with Firefox when trying to view various on-line training videos. At some web sites, the video associated with the page will not play and we get the messages shown below. The Download statement is actually a link and was used to download this rpm file: adobe-release-x86_64-1.0-1.noarch.rpm. "Cannot Play Video" "The latest version of Adobe Flash is required to play this video." "Download the free Flash player here." The intern did not install this rpm because doing so outside of yum did not seem like a good idea. We also do not really know how the Adobe Flash utility is called up by Firefox and whether or not the installation would solve the problem or possibly cause other problems. This problem is not happening on our Windows 7 machines, but not everyone here has a Microsoft machine to use. On Windows, the Firefox occasionally updates itself when launched so that might explain the difference. The training videos always do play on Windows 7 systems when the web pages are brought up. We also noticed that on Windows 7 there are no Firefox related processes remaining after closing all Firefox browsers. This is not the case on our CentOS 6 systems as indicated in the output below. Is this video viewing issue a common problem, and if it is, can someone provide some direction to correct it. Thanks. ++ [user@computer ~]$ ps -elf | grep firefox 0 S user 3872 1 0 80 0 - 68607 poll_s Nov08 ? 00:00:00 /usr/lib64/firefox/bundled/libexec/at-spi-bus-launcher 0 S user 8178 8149 0 80 0 - 25832 pipe_w 19:42 pts/2 00:00:00 grep firefox [user@computer ~]$ ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
[CentOS] Disk Performance Issue
We have a very old Dell desk top machine that has been running CentOS 6 for the past five years. It received a new, 1 TB disk and additional memory before the OS installation. It has been the primary Linux machine in our smallest and most remote field office. It has been updated at least once a week and has all current dates installed. Boot-up this morning lasted about six times as long as usual. Disk access, as indicated by the disk activity light, is almost continuous and for extended periods of time when ever something is done that requires the disk. Everything observed happens whether or not the machine is connected to our network. All of our files appear to be accessible if one is patient. One theory put forward is that some application is running that uses up CPU and disk bandwidth. Another theory is that thereare disk errors, mostly corrected by EDCS features. We do not see any rogue applications and error logs show no disk issues. This is a mysterious issue that we hope to circumvent by putting a new disk and installing CentOS 7 from DVD. Our hope is that the current disk can be mounted externally on the new CentOS system using a USB to SATA adapter and that data can be moved off of the old disk. Advice regarding this issue and any possible diagnostic methods will be greatly appreciated. df -k output: +++ Filesystem 1K-blocks Used Available Use% Mounted on /dev/mapper/vg_delle520-lv_root 51475068 12110896 36742732 25% / tmpfs 1928152 176 1927976 1% /dev/shm /dev/sda1 487652 211073 250979 46% /boot /dev/mapper/vg_delle520-lv_home 905124888 246856176 612284356 29% /home +++ ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
[CentOS] mplayer
We recently installed CentOS 7 from DVD. Our install selection was the GNOME desktop option. yum update yielded about 465 megabytes of updates all of which were successful with no warnings. The multi media option was not chosen because KDE was listed. GNOME was not apparent in the software list for the multi media workstation install. Google searches led us to instructions for installing mplayer. The repo update appears to be successful as indicated below. Dependency resolution at the time of mplayer installation yielded twelve errors. Are there other packages that could be installed prior to another attempt at mplayer installation that might provide the missing items? Might these errors have been avoided by choosing the multi media workstation install? Thanks. ++ [user@computer ~]$ yum repolist Loaded plugins: fastestmirror, langpacks Determining fastest mirrors * base: centos-distro.cavecreek.net * epel: mirrors.sonic.net * extras: centos-distro.cavecreek.net * nux-dextop: mirror.li.nux.ro * updates: centos-distro.cavecreek.net repo id repo name status base/7/x86_64 CentOS-7 - Base 10,019 epel/x86_64 Extra Packages for Enterprise Linux 7 - x86_64 13,237 extras/7/x86_64 CentOS-7 - Extras 419 nux-dextop/x86_64 Nux.Ro RPMs for general desktop use 1,603 updates/7/x86_64 CentOS-7 - Updates 2,137 repolist: 27,415 [user@computer ~]$ --> Finished Dependency Resolution Error: Package: mplayer-1.1-33.20150505svn.el6.nux.x86_64 (nux-dextop) Requires: libgnutls.so.26()(64bit) Error: Package: ffmpeg-libs-2.6.8-3.el6.nux.x86_64 (nux-dextop) Requires: libopenjpeg.so.2()(64bit) Error: Package: mplayer-1.1-33.20150505svn.el6.nux.x86_64 (nux-dextop) Requires: libcdio.so.10()(64bit) Error: Package: mplayer-1.1-33.20150505svn.el6.nux.x86_64 (nux-dextop) Requires: libcdio_cdda.so.0(CDIO_CDDA_0)(64bit) Error: Package: librtmp-2.4-0.3.20110811gitc58cfb3e.el6.nux.x86_64 (nux-dextop) Requires: libgnutls.so.26()(64bit) Error: Package: ffmpeg-libs-2.6.8-3.el6.nux.x86_64 (nux-dextop) Requires: libgnutls.so.26()(64bit) Error: Package: faac-1.28-2.el6.nux.x86_64 (nux-dextop) Requires: libmp4v2.so.0()(64bit) Error: Package: mplayer-1.1-33.20150505svn.el6.nux.x86_64 (nux-dextop) Requires: libcdio_paranoia.so.0()(64bit) Error: Package: ffmpeg-libs-2.6.8-3.el6.nux.x86_64 (nux-dextop) Requires: libgnutls.so.26(GNUTLS_1_4)(64bit) Error: Package: mplayer-1.1-33.20150505svn.el6.nux.x86_64 (nux-dextop) Requires: libcdio_paranoia.so.0(CDIO_PARANOIA_0)(64bit) Error: Package: librtmp-2.4-0.3.20110811gitc58cfb3e.el6.nux.x86_64 (nux-dextop) Requires: libgnutls.so.26(GNUTLS_1_4)(64bit) Error: Package: mplayer-1.1-33.20150505svn.el6.nux.x86_64 (nux-dextop) Requires: libcdio_cdda.so.0()(64bit) You could try using --skip-broken to work around the problem You could try running: rpm -Va --nofiles --nodigest [root@root user]# ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
[CentOS] gedit font size
We recently installed CentOS 7 on a system. We chose the GNOME desktop install option and have used yum to install all of the available updates. The first run of yum update yielded about 450 megabytes of items to be installed or updated. All of the updates have been successful. One issue with our new CentOS system is that some users want to use gedit, but the displayed font size is extremely small. Internet searches for a way to increase font size have not yielded any useful information. Is there a standard method to make the gedit font size larger? Thanks. ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
