/ - rtt - IT Resource

  • systemd management using systemctl and journalctl to check systemd logs


    systemd is like the service manager for your Centos and other modern Linux distributions (including Debian/Mint/Ubuntu) allows you to enable services, stop them, restart them, check their status and even reboot your system. The key commands or arguments you will use with systemctl are the following: Unit Commands:   list-units [PATTERN...]         List loaded units &nbs........
  • Linux What is umask (user mask) for file and directory creation permissions and how to calculate umask and change the defaults


    umask are the default permissions that are applied when a file or directory are created.  To see this in action simply just "touch filename" or "mkdir somedir" and you'll see what default permissions are applied. The first thing I always tell people you should know is to NEVER change the defaults unless you are making them more restrictive.  But they work well and if you change the defaults you could end up creating a file without permission to read........
  • Centos 7 - Convert Minimal to Graphical GUI GNOME or KDE Desktop


    Did you just install the minimal version by accident or want to install the GUI?  No need to reinstall just tell yum to do the work for you! You could actually have both installed and choose one as your preference on demand (although many people prefer GNOME's simplicity). Step 1.) Install Gnome and/or KDE. To install the GNOME Desktop on Centos 7: yum -y groups install "GNOME Desktop" To........
  • vmkping -I vmk1 10.0.2.69 PING 10.0.2.69 (10.0.2.69): 56 data bytes sendto() failed (Host is down)


    [root@localhost:~] vmkping -I vmk1 10.0.2.69 PING 10.0.2.69 (10.0.2.69): 56 data bytes sendto() failed (Host is down) vsphere distributed switch vmotion not working [root@localhost:~]  esxcfg-route -l VMkernel Routes: Network          Netmask          Gateway          Interface &........
  • zenity popup messages, windows, dialogs, error messages calendars and more howto on Gnome Linux including Ubuntu, Linux Mint, Centos and more


    zenity is a nice utility as part of the gnome window manager that allows you to script from bash and retrieve the input from the user.  It could also be helpful in just notifying a user when they login with a popup window. I'll give an overview of what's available with zenity:   Application Options: --calendar Display calendar dialog --entry Display tex........
  • VMWare Vsphere VCSA Graphical Install Creates json


    yes it does create its own json ============================================ cat /tmp/vcsaUiInstaller/ovftool-20180809-175238948-20180809-175603497.log |grep -i json 2018-08-09T17:56:04.238-07:00 verbose OVFTool[30966] [Originator@6876 sub=Default] Manifest file entry: SHA1(VMware-vCenter-Server-Appliance-6.7.0.12000-8832884_OVF10-file1.json) = 1deb658c724767697587d5909c4051c01813e6a1 -->     <ovf:File ovf:href="VMware-vCenter-Server-........
  • [warn] VirtualHost 10.2.5.101:443 overlaps with VirtualHost 10.2.5.101:443, the first has precedence, perhaps you need a NameVirtualHost directive


    [root@thetor2017 conf]# service httpd restart Stopping httpd:                                            [  OK  ] Starting httpd: WARNING: MaxClients of 3000 exceeds ServerLimit value of 300 servers,  lowering MaxClients to 300.  To increase........
  • wodim / cdrecord error cannot burn DVD or BDR .iso Errno: 5 (Input/output error), write_g1 scsi sendcmd: no error


     dvd+rw-mediainfo /dev/sr0 INQUIRY:                [ASUS    ][BW-16D1HT       ][3.00] GET [CURRENT] CONFIGURATION:  Mounted Media:         11h, DVD-R Sequential  Media ID:              RITEKF1  &n........
  • How to qemu-kvm enable bridged networking in Debian Ubuntu Linux Mint on KVM containers


    I've read a few guides about this but they didn't work for me. sudo apt-get install bridge-utils #don't think the above is enough it won't work still even though you have by default an /etc/qemu-ifup that handles it if you have the right tools and setup sudo qemu-system-x86_64 -net tap -net nic -enable-kvm -cpu host,vmx=on ~/VirtualBox VMs/vsphere-vcenter/vsphere-vcenter.vdi W: /etc/qemu-ifup: no bridge for guest interface foun........
  • VSphere InternalServerError - Error When Adding Permissions


    InternalServerError (com.vmware.vapi.std.errors.internal_server_error) => { messages = [LocalizableMessage (com.vmware.vapi.std.localizable_message) => { id = vapi.bindings.method.impl.unexpected, defaultMessage = Provider method implementation threw unexpected exception: com.vmware.vapi.std.errors.InternalServerError, args = [com.vmware.vapi.std.errors.InternalServerError] }], data = <null> } I was getting the........
  • VMWare 6.7 VCSA VSphere ESXi Management SSO Install Guide on Linux using the CLI


    #mount the VCSA DVD mount /dev/sr0 /mnt/cd #alternatively you could mount the iso directly mount -o loop vcsa.iso /your/mount/path #for this purpose we are using the CLI installer on Linux cd /mnt/cd/vcsa-cli-installer/lin64 #no it's not going to be that easy you can't just run vcsa-deploy like that you need to use a template or configured .json file ./vcsa-deploy Usage: vcsa-deploy [-h] [--version] [--supported-deploymen........
  • Linux Mint Black Screen after boot no graphics solution


    This is not the normal "black screen" issue and I was shocked to eventually find out why.  The normal advice of reconfiguring Xorg didn't work.  Even booting into "Recovery Mode" did not help. Here is the short end of the stick that fixed it: sudo apt-get install mdm mate-desktop-environment Yes you got it right, mdm and the mate-desktop-environment / gnome were somehow uninstalled.  This must be whe........
  • Centos PXEBoot NetInstall Failure - Pane is dead


    ValueError: new value non-existent xfs filesystem is not valid as a default fs type Pane is dead From what I read this is misleading and has to do with the fact that the initrd and kernel are mismatched. This is a hard situation because for some older hardware I am using the Centos Plus kernel which has modules that I require for an older server/NIC.  This seems to have cropped up in the past few months and there is no simple fix........
  • Linux Ubuntu Mint Debian cannot play xvid,x264,mp4 or any videos codec issue - xplayer Could not initialize supporting library.


    In xplayer I get the following error "Could not initialize supporting library.".  It actually looks more like a gstreamer issue. For those wondering what the default video player is called it is "xvid" and not "totem" anymore like previous versions. Basically it looks like some codecs are missing when I uninstalled another program it uninstalled other programs and codecs that it shouldn't have. I've tried installing all the gstre........
  • SMF Forums / Simple Machines Forums Not Displaying Images Theme or Styles Properly using 127.0.0.1


    This is one thing that has me wondering about SMF.  It is apparently a known issue but in the latest version and new install nothing looked right because it was using http://127.0.0.1 to find everything!  How on earth would it ever do this or think it is normal? Excerpt of crazy html code it produces that causes the issue:     <link rel="stylesheet" type="text/css&qu........
  • Apache htaccess Custom ErrorDocument not working properly for root home page 403 Error Issue and Solution


    So I have a domain "testdomain.com". Inside test domain.com's root is the following .htaccess: Options +FollowSymLinks -Indexes ErrorDocument 403 /launch/index.html Order Deny,Allow Deny From All Allow From 192.168.1.2 When you visit anything other than root things work fine.  Eg. if you visit http://testdomain.com/somedirfile.html It will show the right error in /launch/........
  • syslinux / pxelinux how to boot from local drive how to


    Just type the command: localboot By default it will boot the first local drive "0".  I believe you can specify a different number to boot a different device. eg. localboot 3 (will boot the 4th BIOS device)'........
  • How To Install Windows Server 7 8 10 12 2008 2012 2014 2016 Servers Desktops using Linux tftp, dhcpd and samba


    It has been a big pain for a long-time to install Windows from a Linux environment.  I used to run a windows install server and it never worked right for some reason (the install would fail on most servers). Before getting start be sure to setup your samba share so once you boot into WinPE you can mount the install for whatever Windows you want /etc/samba/smb.conf [smbwinstall] path = /tftpboot/images/winstall guest ok = yes........
  • Unable to load dynamic library '/usr/lib64/php/modules/module.so' - /usr/lib64/php/modules/module.so: cannot open shared object file: No such file or directory in Unknown on line 0


    Getting this error on Centos 6 with PHP 5.3 when just running "php -v"   PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/lib64/php/modules/module.so' - /usr/lib64/php/modules/module.so: cannot open shared object file: No such file or directory in Unknown on line 0 PHP Warning:  Cannot load module 'XCache' because conflicting module 'apc' is already loaded in Unknown on line 0 Solution:........
  • PHP geoip.so fatal error Solution


    PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/lib64/php/modules/geoip.so' - /usr/lib64/php/modules/geoip.so: undefined symbol: GeoIP_country_code_by_name_v6 in Unknown on line 0  Remove the GEOIP from PHP: php71w-pecl-geoip-1.1.1-1.w6.x86_64   PHP Fatal error:  PHP Startup: apc_shm_create: shmget(0, 67108864, 914) failed: Invalid argument. It is possible that the........
  • Linux last command show login by IP instead of hostname


    In the "last" command in Linux by default it will show the information with the hostname (not very useful at all especially since it normally truncates long hostnames). To get last to show the IP address use this: last -i The -i makes it show the numeric IP instead of hostname.........
  • Install Windows From a Linux TFTP Server instead of using WDS Solution


    yum -y install samba vi /etc/samba/smb.conf https://www.kernel.org/pub/linux/utils/boot/syslinux/syslinux-6.03.zip mkdir syslinux;cd syslinux;unzip syslinux-6.03.zip mkdir -p /tftpboot/libs/ cp bios/com32/modules/linux.c32 /tftpboot/libs/ cp bios/com32/libutil/libutil.c32 /tftpboot/libs/ cp bios/com32/lib/libcom32.c32 /tftpboot/libs/ #add lib path echo "PATH libs" >> /tftpboot/pxeli........
  • How To Secure Samba NMBD/SMBD to bind to a specific IP address


    By default Samba SMB/NMB listen on ANY and ALL IPs on your system by binding to 0.0.0.0.  Obviously this is a huge security risk if you have a public facing server with both internal and external access.  Usually when a system administrator sets up a samba server their intention is just to share with a LAN. To do this you need to the following options under the [global] section in smb.conf bind interfaces only = yes interfaces = 192........
  • ffmpeg how to watermark and concatenate in one command


    If you were in my boat you were frustrated that you had to double encode, eg. one separate encode for watermark and a separate from concat and it's not easy to figure out this with ffmpeg on your own.  However it is a nice way to save time! ffmpeg -i file1.mp4 -i file2.mp4 -i file3.mp4 -i watermark.png -filter_complex "[0:v]setpts=PTS-STARTPTS[v0]; [1:v]setpts=PTS-STARTPTS[v1]; [2:v]setpts=PTS-STARTPTS[v2]; [v0][0:a][v1][1:a][v2][2:a]concat=n=3:v=1:a=1[v][aout]; [v][3:........
  • /usr/bin/ld: cannot find -lboost_system-mt-s /usr/bin/ld: cannot find -lboost_filesystem-mt-s /usr/bin/ld: cannot find -lboost_program_options-mt-s /usr/bin/ld: cannot find -lboost_thread-mt-s collect2: error: ld returned 1 exit status make: *** [cag


    cagecoin linux compile: sudo apt-get install qt4-qmake libqt4-dev build-essential libboost-dev libboost-system-dev         libboost-filesystem-dev libboost-program-options-dev libboost-thread-dev         libssl-dev libdb++-dev libminiupnpc-dev Solution:  sed -i s/"BOOST_LIB_SUFFIX=-mt-s"/"#BOOST_LIB_SU........
  • ffmpeg Unable to Use Hardware Encoding with Nvidia 3.40 Driver and GT210 card


    I believe from what I've read that this card's driver doesn't support the features after trying all known troubleshooting methods. ffmpeg -i uservideoRendered.mp4 -filter:v hwupload_cuda,scale_npp=w=1920:h=1080:format=nv12:interp_algo=lanczos,hwdownload -c:v hevc_nvenc -profile main -preset slow -rc vbr_hq -c:a copy uservideoRendered.mp4-test ffmpeg -i uservideoRendered.mp4 -filter:v hwupload_cuda,scale_npp=w=1920:h=1080:format=nv12:interp_algo=lanczos,hwdownload........
  • Migrate Centos 7 from Single HDD to mdadm RAID 10 array:


    Done on Centos 7.3 very important as clearly based on older guides it was a lot easier and more simpler!  Hint do not use grub2-install! One huge caveat if you are an oldschool user or sysadmin who has avoided UEFI booting The normal way will not work here if your Centos was using UEFI.  Newer systems use it by default. The easiest way to check is to do an fdisk -l if your sy........
  • How to change reserved blocks in Linux partition


    user@box:~$ sudo tune2fs -l /dev/md99 [sudo] password for user: tune2fs 1.42.9 (4-Feb-2014) Filesystem volume name:   <nuser> Last mounted on:          /mnt/md50 Filesystem UUID:          976a8655-2619-4587-878c-dab07f7b7652 Filesystem magic number:  0xEF53 Filesystem revision #:    1 (dynamic) Fi........
  • Centos 7 Cudaminer Nvidia setup guide


    I am using a GTX 1060 but replace the download for the driver with the correct/current version for your particular card by visiting: http://www.nvidia.com/Download/index.aspx?lang=en-us   yum install automake curl openssl-devel libcurl-devel gcc gcc-c++ yum -y install kernel-devel-`uname -r` yum -y install unzip #the........
  • Apache SSL very slow response with Firefox Freezes/Loads Very slow when checking self-signed SSL certificate


    I was sure this was a Centos bug with OpenSSL, Apache, MySQL or even PHP.  I tried everything but nothing helped.  One clue is that if you check the Apache logs you will see nothing in the access logs until minutes later (this means Firefox has not even passed your request to the remote Apache/htttpd server). When even accepting the invalid certificate message that would show up minutes later when trying to "View the Certificate" Firefox would freeze.  This bu........
  • Track 01: 34 of 1726 MB written (fifo 100%) [buf 99%] 3.6x.Errno: 5 (Input/output error), write_g1 scsi sendcmd: cmd timeout after 1.897 (40) s CDB: 2A 00 00 00 44 A9 00 00 1F 00 resid: 6144 cmd finished after 1.897s timeout 40s write track da


    These errors believe it or not are simply because of not being the root user or running with sudo! However if you didn't know to try as root you'd think there was a problem with your burner or disc  Essentially it looks like without root you cannot send the required scsi commands to continue writing.  I think cdrecord should have built-in tests or safeguards to see if it has the permissions to run the required commands. I guess for more advanced users the idea is simila........
  • Linux Mint Install Netboot PXE Guide Howto


    *Update so this doesn't work it must be something to do with the path of nfs or something else but the installer fails with "Installer crashed" at the end whereas with the CD/USB it works. This assumes you've already installed and configured a separate PXE/DHCP server somewhere else and your /tftpboot directory is setup. This is for Linux Mint 18.1 but generally applies to most versions although you may have tro change things like "casper"........
  • Centos 7 Migration Guide from Centos 6


    Centos 7 is no cakewalk, there are many fundamental features and basic utilities that are missing or even completely renamed or different! Another shocking thing is to check your NIC it is set by default to not turn on when booting! And by the way there is no more standard eth0 the NIC convention is now "enp0s3" vi /etc/sysconfig/network-scripts/ifcfg-enp0s3........
  • Migrating from Linux Mint 17.2 mdadm RAID array to a new one (because I upgraded to larger drives).


    1.) Replicate the number of partitions in your new drives. gdisk /dev/sda gdisk /dev/sdb I created 3 partitions of the same same size. partition #1: +1G (/boot) partition #2: +60G (swap) partition #3: rest of it (/) #note if you are using GPT/gdisk you need to create separate a partition at least 1MB in size (in my case I would a 4th partition and mark it type ef02).........
  • DRBD Split-brain solution


    Uh oh [17925926.174277] block drbd0: Handshake successful: Agreed network protocol version 96 [17925926.174325] block drbd0: conn( WFConnection -> WFReportParams ) [17925926.174342] block drbd0: Starting asender thread (from drbd0_receiver [1682]) [17925926.174432] block drbd0: data-integrity-alg: <not-used> [17925926.174581] block drbd0: drbd_sync_handshake: [17925926.174586] block drbd0: self 2AAE66AF9252D6DB:2815BF........
  • apc_shm_attach: shmat failed: in Unknown on line 0 & apc_shm_create: shmget(0, 67108864, 914) failed PHP Solution


    PHP Fatal error:  PHP Startup: apc_shm_create: shmget(0, 67108864, 914) failed: Invalid argument. It is possible that the chosen SHM segment size is higher than the operation system allows. Linux has usually a default limit of 32MB per segment. in Unknown on line 0 PHP Fatal error:  PHP Startup: apc_shm_attach: shmat failed: in Unknown on line 0 This error is not at all fun because it actually prevents Apache/httpd from starting or working at all. It will........
  • mdadm kernel panic if trying to change --layout on a RAID10


    It is already known this is not possible   mdadm --create /dev/md3 --level 10 --layout=f2 --raid-devices=2 /dev/sdc1 /dev/sdd1 mdadm: /dev/sdc1 appears to be part of a raid array:        level=raid10 devices=2 ctime=Sat Dec 24 18:44:29 2016 mdadm: /dev/sdd1 appears to be part of a raid array:        level=raid10 devices=2 ctime=Sat Dec 24 18:44:29 2016 Continue creating ar........
  • mdadm mirrored RAID1 performance using RAID10 -f2 (Far Layout) is the solution


    The only way I've found in mdadm to make 2 drives perform like a proper RAID 1 (eg. the read speed should be 2x that of a single drive) is to use the --layout=f2 (far 2).   mdadm raid10 performance issues. Be very aware that mdadm seems to default to layout=n2 (which means near). In this scenario it means it is like mdadm RAID 1 performance (you get maximum read speeds of a single drive). dd if=/dev/md126 of=/dev/null bs=1M cou........
  • Linux How To Recover Partition Table from Kernel and Restore Centos/Debian etc..


    We've all done this at some point, you work on the wrong shell window and this was my first time making this mistake but I deleted a partition table in fdisk, recreated it and saved it with "wq" and even ran partprobe!  If you haven't rebooted yet then you can still recover your partition table, otherwise you're in big trouble. Fortunately since it was a live system and in use the kernel still had to use the old table like below:........
  • Linux Mint 17 How to Enable File Sharing Option in File Manager


    I still cannot understand how this would not be enabled by default and I struggled to find the reason why with manually installing samba etc.. wondering why the option for sharing was not in the menu.   On Linux Mint "MATE" the package is called "caja-share" and on Cinnamon it is called "nemo-share" so edit the below command as necessary: *Also note that the "samba" package is necessary as it is not inst........
  • Apache Centos Stopping httpd: [ OK ] Starting httpd: [Wed Jun 29 19:29:44 2016] [warn] _default_ VirtualHost overlap on port 80, the first has precedence [Wed Jun 29 19:29:44 2016] [warn] _default_ Virtual


    Stopping httpd:                                            [  OK  ] Starting httpd: [Wed Jun 29 19:29:44 2016] [warn] _default_ VirtualHost overlap on port 80, the first has precedence [Wed Jun 29 19:29:44 2016] [warn] _default_ VirtualHost overlap on........
  • HTML files in Apache still displaying as raw text even with DefaultType, ForceType etc.


    There was only one solution here and it was the following: edit /etc/httpd/conf/httpd.conf Comment the lines for the Mime Magic Module: #   MIMEMagicFile /usr/share/magic.mime #    MIMEMagicFile conf/magic   *Don't forget to restart Apache and clear your browser cache twice I was using DefaultType and ForceType a........
  • There was a problem importing one of the Python modules required to run yum. The error leading to this problem was:


    There was a problem importing one of the Python modules required to run yum. The error leading to this problem was:    No module named yum Please install a package which provides this module, or verify that the module is installed correctly. It's possible that the above module doesn't match the current version of Python, which is: 2.7.9 (default, Apr 21 2016, 16:51:58) [GCC 4.4.7 20120313........
  • Linksys PAP2T No delay in dialing recommended fast dial plan


    I modified the default to the following for faster local dialing for North American area codes: (*xx|[3469]11|0|00 [2-9]xxxxxxS0|[2-9]xxxxxxxxxS0|1xxx[2-9]xxxxxxS0|xxxxxxxxxxxx.) This is what I added to the above: "[2-9]xxxxxxxxxS0" so any 9 digit number is dialed instantly xxx-xxx-xxxx (the S0 at the end makes it dial right away).  This makes dialing much quicker and is recommended. *No........
  • Linksys E2500 DD-WRT Upgrade Instructions and Enabling 5ghz with Tomato Firmware


    1.) Flash directly to this file: http://tomato.groov.pl/download/K26RT-N/build5x-132-EN/Linksys%20E-series/tomato-E2500-NVRAM60K-1.28.RT-N5x-MIPSR2-132-Max.zip *I was never able to get the larger "Mega" file to work, at least not initially so I recommend the file above. To enable 5ghz I had to do the "Clear NVRAM" Option before it was shown. 2.) Or if you don't need 5ghz (most devices do not support it and cannot........
  • PAP2T Linksys VOIP strange ring problem


    The problem is that the default of most of these units is set for non-North American phones so the ring sounds like it cuts off and is not  sequential. How To Fix the Issue Click on "Regional" and make sure you are in Advanced mode.    ........
  • Debian Linux Ubuntu Mint connect to pptp from terminal bash shell


    apt-get install pptp-linux echo "yourvpnusername * yourpasspass *" >> /etc/ppp/chap-secrets vi /etc/ppp/peers/provpnaccounts.com enter (ignore the lines): ============ pty "pptp server.provpnaccounts.com --nolaunchpppd" name testuser #remotename PPTP require-mppe-128 file /etc/ppp/options.pptp ==========........
  • Linux Debian/Ubuntu/Centos How To Force Internet Traffic Through PPTP L2TP OpenVPN Account Only


    The following assumes the computer is local/physical to you and/or it always has a LAN IP so it can be accessed on site without having a default gateway. The key to this is not to set a default gateway for your computer or you can set a script on boot or other time to delete the gateway (where eth0 is the NIC you are using): route del default eth0 50.80.20.2 is the VPN server you connect to 192.168.1.1 is your........
  • Centos 6 how to guide convert LVM non-RAID into mdadm 1/10 RAID array live without reinstalling


    Here is the scenario you or a client have a remote machine that was installed as a standard/default minimal Centos 6.x machine on a single disk with LVM for whatever reason.  Often many people do not know how to install it to a RAID array so it is common to have this problem and why reinstall if you don't need to?  In some cases on a remote system you can't easily reinstall without physical or KVM access. So in this case you add a second physical or disk or already ha........
  • Virtualbox errors on Ubuntu/Debian/Mint


      The solution was to reinstall the vbox dkms package and do a manual modprobe of the modules it makes. I never sorted out the unable to start due to the USB issue, I did have the guest additions installed but the only way to boot was to change the pointing device from USB to PS2 and then to disable the USB controller (if your pointing device is set as USB, disabling USB will not work because it will re-enable by default when it sees your pointing device is USB, this is w........
  • OpenVZ Install Guide Again / Quick Setup


    yum -y install wget wget -P /etc/yum.repos.d/ http://ftp.openvz.org/openvz.repo rpm --import http://ftp.openvz.org/RPM-GPG-Key-OpenVZ yum -y install vzkernel vzctl #enable ip_forward sed -i s/'net.ipv4.ip_forward = 0'/'net.ipv4.ip_forward = 1'/g /etc/sysctl.conf #all interfaces should not send redirects echo "net.ipv4.conf.default.send_redirects = 1" >> /etc/sysctl.conf echo "net.ipv4.co........
  • Unable to configure RSA server private key SSL Library Error: 185073780 error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch


    [Tue Jun 23 02:05:52 2015] [error] Unable to configure RSA server private key [Tue Jun 23 02:05:52 2015] [error] SSL Library Error: 185073780 error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch The above is an accurate description of what is wrong. In our case the client made a simple mistake of thinking the localhost.crt and localhost.key (default key locations for Apache SSL in Centos) were in the same directory but they we........
  • Centos OpenDKIM & Postfix Setup Guidel


    #from epel repo yum -y install opendkim chkconfig opendkim on cd /etc/opendkim/keys opendkim-genkey -vd mail.server.com opendkim-genkey: generating private key opendkim-genkey: private key written to default.private opendkim-genkey: extracting public key opendkim-genkey: DNS TXT record written to default.txt  ........
  • cPanel how to force reinstall rpms and fix packages and other problems caused by updates or duplicate rpms


    <p>If a service is not working and resetting it to defaults is not working and you get bizarre error messages it is probably a broken update and possibly duplicate package.</p> <p>Take in this case &quot;exim&quot; not working even after resetting to defaults.</p> <p><strong>Check for duplicates:</strong><code><br /> </code></p> <p><code>rpm -aq|grep exim<br /> </code></p> <p><c........
  • Linux disable firmware prevents NIC/Ethernet from working phy0 -> rt2x00lib_request_firmware: Error - Failed to request Firmware.


    [   17.208336] tg3 0000:08:00.0: eth0: Link is up at 1000 Mbps, full duplex [   17.210194] tg3 0000:08:00.0: eth0: Flow control is on for TX and on for RX [   76.000065] phy0 -> rt2x00lib_request_firmware: Error - Failed to request Firmware. [   76.002332] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [   86.736004] eth0: no IPv6 routers present [  148.960038] phy0 -> rt2x00lib_request_fi........
  • VPN Account Buyers Guide and General Info


    What does VPN stand for? VPN stands for Virtual Private Network and is a secure way of connecting networks and devices. In the context we're talking about it will usually be a client-server solution and not connecting whole networks or businesses. The assumption is that most people reading this are trying to secure their internet connection, privacy and hide or change their IP address. Why use a VPN? There are many........
  • cPanel How to set SSL and Dedicated IP in cPanel


    Account Functions -> Change Site's IP Address Choose the domain and then click "Change" Choose the new IP 1.) Setup SSL Certificate in cPanel Click on "SSL/TLS Manager" under the "Security" section. 2.) Under " Private Keys (KEY)" Click "Generate, view, upload, or delete your private keys." Choose "Key Size: 4096........
  • firefox android text size inconsistent large and small text size solution


    This is very annoying and also hard for web developers who want to see how things look on Android.  You may be fooled into thinking you have an unclosed bracket or incompatible code but this is the "text inflation feature" which I feel should be disabled by default.  It works so inconsitently that one block of text will appear small while the other will be huge and is quite annoying. The solution is simple Settings -> Display and &q........
  • PayPal subscriptions automatically cancelling after creation of profile


    <p>There is a weird quirk with how this works, but there is a variable called &quot;src&quot; that defaults to 0 or disabled if not specified as 1.</p> <p>The default 0 means not to recur billing on a subscription.&nbsp; It's too bad it's not more obvious anywhere nor is there an explanation or warning during payment or after to both the seller and buyer.</p> <p><strong>Here's a proper subscription code example that does recur and does not cancel........
  • Thunderbird Error An error occurred while loading or saving configuration information for thunderbird. Some of your configuration settings may not work properly.


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    Moving to RAID was a pain. What you have to do is the following from an existing install: Install mdadm Create your mdadm RAID 1 array on your spare hard drive. Start it with the missing disk. rsync the entire contents of your current / to the md partition. Here's a good way of doing it: rsync -Pha --exclude=/proc/* --exclude=/sys/* --exclude=/mnt/* /. /mnt/md2........
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  • connect: No buffer space available Oct 18 12:21:03 vps kernel: printk: 177 messages suppressed. Oct 18 12:21:03 vps kernel: Neighbour table overflow.


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  • Linux How To Add/Delete A Default Route/Gateway


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  • FUSE/Curlftpfs mount ftp account as drive partition in Linux


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    I have an md0 arary that my Centos install refers to.  I feel this is half the reason why it won't boot anymore. I saw the initrd for Centos was assembling it as md127 even though it was known as md0. The reason for this is because I used mdadm --assemble --scan to detect the array on a LiveCD.  I had no idea this name would stick (but now I realize the name is permanently stored in the metadata once you mount md127 or whatever random name assemble gives it).  W........
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  • Centos 5.5 RAID 1 boot issue


    I installed 5.5 with a 300GB RAID 1 partition (boot is also on this partition).  It booted up fine the first few times until after I used a Live CD and accessed the array, and it became named /dev/md127 for some reason. Now whenI boot into CentOS I get a kernel panic and different errors, once I got "invalid superblock", even though the array is fine (it didn't happen again, probably because I was sure to dismount and stop the mdadm array properly). Here's what........
  • Canel Default VHOST DocumentRoot/Contents Directory is /usr/local/apache/htdocs


    This can be very annoying and CPanel doesn't seem to document it, or it's not found or made as obvious as it should be.  It's always funny when I find it more difficult to work with a control panel than to do everytihng manually without CPanel or even Plesk. So once again, the default serve path for contents is: /usr/local/apache/htdocs and this is especially applicable when accessing Apache by just an IP which is unbound to any domain at this point.........
  • rsync my favorite/best/optimal default switches and options


    Not sure what rsync switches/options to use? rsync -PDrphogtl The short version would be: rsync -Pha I think these are really common sense options to use and probaby should be the default. Explanation of rsync switches P = display the progress D = hybrid of --specials and --devices so all special and device files will be copied as well. r = recursive (otherwise rsync won't copy files deeper than........
  • Convert HDD/Hard Drive Partition(s) into non-RAID into RAID 1 using existing data without data loss and without reformatting.


    Before we start I take no responsibility for this, you should have a backup and if you make a mistake during this process you could wipe out all of your data.  So backup somewhere else before starting this as a precaution, or make sure it's data you could afford to lose. The RAID 1 Setup (Hardware Wise) I've already setup my 2 x 1TB (Seagate) drives with identical partitions, make sure your new hard drive (the empty one) is setup like your curr........
  • Linux EXT3 16GB-17GB maximum filesize issue solved/how to fix


    I have no idea why but mkfs.ext3 defaults to a patheticlly small blocksize of 1024 bytes/1KB (kilobyte).  That means the maximum filesize is ONLY 16GB!  With 2KB/2048 bytes you get a 256 GB maximum filesize, and with 4KB/4096 bytes you get 2TB! I finally noticed/paid attention to this after realizing that with rsync and scp that no file larger than 17GB could be transferred.  I then realized it must be a file size limit on the partition. Here is what tune2fs tol........
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    It's basically free bash shell script available from: http://wpkg.org/email2fax/index.php/Main_Page Make sure you have the required tools: libtiff ghostscript mpack/munpack Where you can e-mail your Asterisk box and it will fax it to the phone number in the subject line.  The good news ends there, it is fairly undocumented and buggy. Take for example how the documentation mentions you can invoke from the com........
  • Picking an FTPD (vsftpd) Server in Linux Centos/Debian


    I decided on using yum to help me decide even though I normaly use proftpd I decided to see what else I could find. yum search ftp Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile  * rpmforge: ftp-stud.fht-esslingen.de  * base: mirrors.netdna.com  * updates: updates.interworx.info  * addons: yum.singlehop.com  * extras: mirrors.netdna.com rpmforge   ........
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    PHP cannot access /usr/bin/opensslI have verified the username that runs the process is able to access /usr/bin/openssl and it does exist but the PHP script is saying it doesn't exist: [code:1:1fd0f3abbe] if (!file_exists($OPENSSL)) { //echo "ERROR: OPENSSL $OPENSSL not foundn"; }[/code:1:1fd0f3abbe] I don't get itI can clearly see the contents of /usr/bin by using the PHP system fu........
  • Change default shell


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  • Need identd for port 113 ? Install authd


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  • CVSUp the Easy Way


    CVSUp the Easy WayIf you're reading this you probably have never used CVSUp or don't know how. CVSUp can be used for two things or just one if you prefer. *Keeping your kernel up to date *Keeping your port list up to date Start by editing the following file in: [b:76928b387d]vi /usr/share/examples/cvsup/cvs-upfile[/b:76928b387d] It can be quite overwhelming with all the crazy options. Basically there are only 3........
  • Load Balancing/Clustering


    Load Balancing/ClusteringAn interesting article that discusses the pros, cons and viability of load balancing/clustering http://www.wwwcoder.com/main/parentid/493/site/4189/68/default.aspx ZoneEdit seems to offer an interesting Fail Over Service as well: http://www.zoneedit.com/doc/faq.html#fo........
  • Wireless/xmit power - DD-WRT v23 SP2 (09/15/06) std - build 3932 Linksys WRT54G/GL/GS


    I played around with xmit power (how much power in mW) to see if I could increase the range and signal strength.  I don't think this Linksys WRT54G's strength is the wireless, it seems to have poor signal quality and transfer rates all around. I think part of the problem is also that there are several wireless networks around my house that could be interfering and the walls are thick here. Anyaway, moving on now :)  The default is 28mW and I increased it to........
  • Apache/Mod_SSL not serving the right/expected certificate?


    There is actually by default a "Default SSL" vhost that can mess things up for you and can cause surprising and unexpected results. Default Apache SSL Cert in /etc/httpd/conf.d/ssl.conf there is a default SSL Virtual Host which screws things up by offering itself instead of the SSL cert I specify in my own vhosts........
  • Create/Enable SSL Certificates for Apache on Linux/Unix Systems eg. Redhat,Centos,Debian


    Shortcut/Easiest Way To Create A Self-Signed Key: openssl req -new -x509 -nodes -days 1530 -out server.crt -keyout server.key Using the above, you instantly create a self-signed certificate valid for 1530 days and you can simply skip to step #5.) below. If You Need a Real SSL Certificate (eg. Equifax/Openssl) then you need to create a CSR request (you'll need to follow Steps 1.) and 2.) in order to create the CSR.  You then upload the CSR Certi........
  • iPhone Enable Tethering Manually Update ipcc Carrier Settings/Update via SSH


    Everyone says there is a "manual" way of doing it and then they tell you to use iTunes, but if you're like me, you're travelling on business in a foreign country and your laptop does not have iTunes and you don't have a way of getting it and/or don't want it. For this example I'm using the provider "du" in Dubai, UAE (United Arab Emirates) but this method works for virtually all providers.  The requirements in this case to truly "manually update........
  • How to avoid web content hijacking/copying/Force content to be accessed by only 1 domain name


    This is something that happens a lot and it is very dirty,  as you probably know each site is hosted on a certain IP address.  Sometimes a domain is hosted by a single IP address and the IP address defaults to this very same domain. This means that if someone buys domain abcd.com and enters your IP address (the one of your website) as the A record, your content will show up on their domain as if it was their own. There is an easy way to prevent this by using .htacces........
  • MySQL Restoring And Dumping/Backing UP MySQL Data/Tables/Databases


    Backing MySQL Databases Backing Up/Dumping All Mysql Databases To A Single File mysqldump --all-databases -u admin -p > allmysqldatabases.sql The "-all-databases" clause is pretty obvious isn't it?  It means that it will backup all databases. The "-u admin" means login using the user "admin", if you h........
  • Apache Ignoring/Not processing .htaccess file


    I was getting very frustrated one day wondering why it appeared my .htaccess file was being ignored and not processed by Apache.  No matter what I did it was obvious that Apache didn't care about my .htaccess file.  Then I realized that the default settings must be in effect, which is that my vhost didn't explicitly allow me to override the default settings. This usually comes down to your vhost settings. Make sure you have an entry like this in your Apache vhost settings in........
  • SSH Server Slow/Lagged/Delayed Login Response


    This is really something the SSH Server developers should consider.  The cause of this annoyance is because of failed DNS lookups on your IP address, which is especially common for many dedicated/col-located servers and also computers on internal NAT/private networks. The chances are this is the cause of your SSH Slow/Delayed Login problems. The easy solution to SSH Login Problems Edit /etc/ssh/sshd_config Add this line to disable r........
  • Configuring OCFS2 Clustered File System on Debian Based Linux including Ubuntu and Kubuntu


    There's a lot of information and guides on OCFS2 for RHEL and Centos Linux but the package setup and configuration is slightly different and this has thrown some people off. Installing OC2FS You should install the following packages to get started: apt-get install ocfs2-tools ocfs2console Configure OC2FS In RHEL/Centos the main configuration file is located in /etc/sysconfig/o2cb However in Debian based Linux it is located........
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