/ - rtt - IT Resource

  • MySQL Using mytop Debug Source of High IO and Slow Performance


    mytop is one of my favorite tools and it is fairly simple aside from a few caveats and issues that persist to this day. To install it on Centos: yum -y install centos Configure ~/.mytop vi ~/.mytop user=root host=localhost db=test #port=3306 socket=/var/lib/mysql/mysql.sock header=1 color=1 Try runni........
  • 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........
  • Linux Permissions and Groups Real Usecase for Group Access


    I have a directory structure which the primary user needs full access on but wanted a user to access only a specific directory within the main directory (so they could write in there only and nowhere else). Here's what I did: [root@compevo8001 dllnow]# ls -alh drwxrwxr-x  2 someuser software  4.0K Oct 19  2017 ExpireYMD-2017-11-20 drwxrwxr-x  2 someuser software  4.0K Nov 19  2017 ExpireYMD-20........
  • Cannot install moodle


    After starting the install it stalls here: admin/index.php?cache=0&agreelicense=1&confirmrelease=1&lang=en If you manually refresh you get a Plugins check screen: Installation System Moodle second step fails just blank screen: https://domain.la/user/editadvanced.php?id=2 Solution: give up and choose something else it shouldn't be thi........
  • gvfs mount in /run/user cannot be accessed or displayed wrong permissions


    The folder contents could not be displayed Backend currently unmounting drwx------ 10 userhere group  260 Aug 23 19:40 .. ??????????  ? ?   ?      ?            ? sftp:host=192.168.8.80,user=adhoc ls: cannot access 'sftp:host=192.168.8.80,user=adoc': Input/output error $ ps aux|grep fuse one       253........
  • Linux bash shell doesn't show username, hostname or current path fix solution


    Usually this is because when you created your user you added a user but didn't create their home directory and/or for some reason your .bashrc and .bash_profile in ~ (home) is broken/missing. In your home just create the following files with the following content to solve it: .bashrc and .bash_profile. To apply it just relogin/start a new bash session # .bash_profile # Get the aliases and funct........
  • 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-........
  • qemu-img resize howto


    The Correct Way To Resize In Place qemu-img resize kvmuserwindows2008dcetest.img +1G Image resized.     Below is a common mistake that some users make they are trying to specify a new image name but it can be resized in place (just make sure the VM is NOT running and you've backed up the data in case something goes wrong). qemu-img resize kvmuser453111.img kvmuser453111-larger.img +5G New i........
  • gmail.com address failing in Postfix


    Aug 10 01:11:54 mailserver postfix/smtp[6180]: 020AE17C2BD1: to=<theuserperson@gmail.con>, relay=none, delay=0.29, delays=0.28/0/0/0, dsn=5.4.4, status=bounced (Host or domain name not found. Name service error for name=gmail.con type=A: Host not found) A user complained that their e-mails weren't being delivered but they actually made a small typo and used gmail.con so it wasn't working as expected of course........
  • Debian Mint Ubuntu compiling xmr-stak


    sudo apt-get install libcurl4-openssl-dev git build-essential autotools-dev autoconf libcurl3 sudo apt-get install libcurl4-gnutls-dev git clone https://github.com/wolf9466/cpuminer-multi sudo apt-get install cmake  libpthread-* libmicrohttpd-dev libssl-dev libhwloc-dev git clone https://github.com/fireice-uk/xmr-stak-cpu.git make install cd bin chmod +x xmr-stak-cpu ./xmr-stak -O xmr........
  • migration/4 migration 4 is using too much CPU


    top - 13:02:52 up 603 days, 19:19,  2 users,  load average: 5.01, 4.15, 3.44 Tasks: 604 total,   5 running, 599 sleeping,   0 stopped,   0 zombie Cpu(s): 17.7%us, 36.1%sy,  0.0%ni, 42.0%id,  4.1%wa,  0.0%hi,  0.2%si,  0.0%st Mem:  16278908k total,  4269684k used, 12009224k free,   119672k buffers Swap:        8k total,    ........
  • Linux Mint 18 Screen Goes Dark or Black After Screensaver or even when using the Desktop Solution


    You can search for this bug and it seems like it may be related to ecryptfs and is many years old. The symptoms are that you return to the computer and the screensaver was active or the screen was asleep/black and it doesn't seem to come back.  But you check by SSH the computer is running fine and are frustrated you'll lose your running programs and have to reboot. There is a simple solution: Ctrl + Alt + F1 Ctrl + Alt + F8 Ba........
  • 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........
  • OpenVPN auth-user-pass-verify ENV script error


    Starting with newer versions of OpenVPN I believe 2.2+ you need to have "script-security 3" set or you can't execute a third party script. Prior to that you could also use the auth-user-pass-verify like this: auth-user-pass-verify ./validate.pl "$username $password $ip" via-env Options error: the --auth-user-pass-verify directive should have at most 2 parameters.  To pass a list of arguments as one of the paramete........
  • Cannot create gradle for conversations


    The main issue is it looks like Java is not configured to accept the invalid ssl cert that is coming from the download location. Exception in thread "main" java.lang.RuntimeException: javax.net.ssl.SSLException: java.security.ProviderException: java.security.InvalidKeyException: EC parameters error  export ANDROID_HOME=/home/user/Downloads/tools/ Conversations-master$ ./gradlew Downloading https://services.gradle.org/distributions/grad........
  • not allowed to execute '/usr/bin/apt-get install eclipse' as root linux sudo user permisson issue and solution


    This is most likely to happen on a normal GUI system like Ubuntu or Linux Mint.  If you or the user is meant to have sudo / root privileges it is as simple as editing the following files: Now assume your username is "iamtheuser" vi /etc/group adm:x:4:syslog,iamtheuser sudo:x:27:anotheruser,iamtheuser Find the above lines and add a comma and "ia........
  • Database Error One or more of the WHMCS database tables appear to be either missing or corrupted. Please check and repair. - WHMCS Solution


    Database Error One or more of the WHMCS database tables appear to be either missing or corrupted. Please check and repair. This error can be misleading especially if you know you are using a known good backup or restoration of the WHMCS database.  The error can also be that the user lacks permissions to read and write to the database. To check to this in MySQL shell: GRANT read,write to dbusername@localhost on dbna........
  • postfix errors fatal: no SASL authentication mechanisms /usr/libexec/postfix/smtpd: bad command startup -- throttling solution


    Jul  3 22:12:17mailserver postfix/smtpd[6195]: fatal: no SASL authentication mechanisms Jul  3 22:12:18mailserver postfix/master[4881]: warning: process /usr/libexec/postfix/smtpd pid 6195 exit status 1 Jul  3 22:12:18mailserver postfix/master[4881]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling This only ever happens in my experience when the authentication method is actually Dovecot.  Usually the problem........
  • mail command line examples of how to send an email using Linux / Unix and the Bash Shell or Scripting


    A simple way that may work for a lot of people who just need basic output for their scripts or daemons to announce an action is this: echo "body or message" | mail -s "realtechtalk.com" user@domain.com If you want to send a text file as the body just do this instead: mail -s "realtechtalk.com" user@domain.com < /tmp/sometxtfile.txt These a........
  • Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10) Dovecot Solution


    This happens because Dovecot limits the maximum IMAP connections per IP to just 10.  This may be fine for a single client side IP but if an entire office or multiple users are behind one IP or a single heavy user is active then you will get bizarre errors in your e-mail clients such as "Password Incorrect" or similar in Thunderbird.  It won't be obvious on the client side as to what the problem is and they will probably just think the server is misconfi........
  • No comments are allowed here Internal Server Error The server encountered an internal error or misconfiguration and was unable to complete your request.


    Internal Server Error The server encountered an internal error or misconfiguration and was unable to complete your request. Please contact the server administrator, root@localhost and inform them of the time the error occurred, and anything you might have done that may have caused the error. More information about this error may be available in the server error log. Apache/2.2.15 (CentOS) Server at testdomain.com Port 80........
  • 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........
  • Mozilla Firefox Address Bar History Not Working places.sqlite corruption solution database repair


    Here is the only solution I found that works in Firefox: *Note you could basically just copy all of the commands in bold (the rest just shows the output)   Install sqlite3 sqlite3 places.sqlite sqlite> .clone places.sqlite-fixed moz_places... done moz_historyvisits... done moz_inputhistory..........
  • sign_and_send_pubkey: signing failed: agent refused operation - SSH Solution


    sign_and_send_pubkey: signing failed: agent refused operation This happens when you don't manually add your ssh key with ssh-add it is some weird new feature in SSH or Ubuntu/Debian that causes this weird problem.   Solution: ssh-add Identity added: /home/user/.ssh/id_rsa (/home/user/.ssh/id_rsa)........
  • How To Set or Change Useragent in Firefox and Seamonkey


    In your browser go to "about:config" Right click and choose "New" -> "String" The name should be: general.useragent.override String Value: Mozilla/5.0 (Linux; U; Android 2.2.1; en-ca; LG-P505R Build/FRG83) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1   You don't even have to restart to make this work.........
  • solution mysqldump: Got error: 1044: Access denied for user 'user'@'localhost' to database 'thedb' when using LOCK TABLES


    It is simple the user just needs to be given the "LOCK TABLES" privilege. As root run this command: GRANT LOCK TABLES ON yourdatabase.* TO yourmysqluser@localhost;........
  • MySQL How To Grant Access To ALL Databases For Export and Backup Purposes


    GRANT SELECT, LOCK TABLES ON *.* TO yourmysqluser@localhost; All you need to do a full MySQL dump on all databases is the SELECT and LOCK TABLES privileges.  This way you don't have to use the mysql root user.  Data could be compromised this way but at least no harm from manipulation, changes or deletion are possible by locking down the privileges to the minimum for a full MySQL dump and backup.........
  • error: Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file Bitcoin Litecoin Error


    error: Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file This is usually because the .cookie file cannot be read by the user you are running Litecoin or Bitcoin client/daemon as. You can adjust the permissions of the file so that the user or group they are apart of has read permissions.  ........
  • Installing SSL Certificate with Chain Intermediary CA File


    Some of the cheaper or newer SSL suppliers will require this to work properly (otherwise you may be prompted that the cert is invalid when it's not the case but it will certainly scare off your users!). In the Apache vhost conf for the domain here is what you add: SSLCACertificateFile /path/to/your/cafile.pem Here is a full example of an SSL Vhost config in Apache using a CA Certificate file <VirtualHost *........
  • How to start screen in bash script or from /etc/rc.local on startup as a specific user


    It takes some tinkering the main thing is that the "-dmS" flag allows screen to start without a session which of course sudo won't have. solution: /usr/bin/sudo -u user /usr/bin/screen -dmS nameyouchoose /script/start.bash this doesn't work at all: /usr/bin/sudo -u user "/usr/bin/screen /script/s........
  • Linux How To Clone One System Harddrive to another remote system


    The easiest way is to use SSH and DD or a combination of netcat.  SSH will be a little slower due to encryption but is the most secure way (on two older systems the average clone speed is about 40-50MB/s).  This is also OS independent as it doesn't matter what the source OS is because you are literallly cloning the drive so you retain the partition table and settings.   Clone HDD using SSH and DD........
  • MySQL Cannot Update/Write to any database table solution


    This happened on Centos for no apparent reason with no obvious issue in the logs.  Data could be read fine but not written (possibly due to some corruption or out of memory issue in the OpenVZ container is the best guess).   All mysql update and insert queries failed freezing without any error log on any database and table. Tried to restart: service mysqld restart Timeout error occurred trying to stop MySQL........
  • mysql how to reset passwords with a few commands


    The commands below will help you reset any mysql user password. use mysql; update user set password=PASSWORD('thenewpass') where User='theusername'; flush privileges;   The first line says to use the "mysql" database which contains all the user info. the second update line sets the new password "thenewpass" for the u........
  • How To Create Apache htpasswd file


    This just simply outputs what you need a username and password that can be used to authenticate from .htaccess htpasswd -nb user password user:Gnb6uE9Lp4gt2   If you want to write it straight to a file htpasswd -cb /tmp/somefile.pw user password How To Use This In .htaccess AuthUserFile /tmp/somefile.pw AuthName GetLost!! AuthType B........
  • Authentication refused: bad ownership or modes for directory /home/user SSH Public Key Authentication Failed Solution


    First of all I got this error after accidentally messing up my usergroup by using usermod -G user group When I would login using SSH keys it would fail: sshd[2020]: Authentication refused: bad ownership or modes for directory /home/one No worries, the fix is simple! chmod g-w /home/use........
  • cannot mount kvm ntfs image


    guestmount -a kvmuserscra.img -m /dev/sda1 mount libguestfs: error: mount_options: /dev/sda1 on / (options: ''): mount: unknown filesystem type 'ntfs' guestmount: '/dev/sda1' could not be mounted. guestmount: Did you mean to mount one of these filesystems? guestmount:     /dev/sda1 (ntfs) guestmount:     /dev/sda2 (ntfs) yum -y install ntfs-3g still........
  • responsive table without changing much code solution


    So you've got a responsive site with tables but it breaks them so anything not viewable on the screen is now cut off. Here is a simple solution that will allow users to scroll horizontally so they can see the whole table: <div style="overflow-x:auto;">   <table>      <tr>          <td></td>    &........
  • userdel user userdel: cannot lock /etc/passwd; try again later.


    I am not sure why this happened I think it's because the file was in use by another duplicate process or script.  userdel user userdel: cannot lock /etc/passwd; try again later.  ........
  • M2Crypto.SSL.Checker.WrongHost: Peer certificate subjectAltName does not match host, expected fedora-archive.ip-connect.vn.ua, got DNS:mirror.ip-connect.vn.ua


    You are using Centos 5 which is deprecated so nothing in yum will work until you follow this post to use the vault: http://realtechtalk.com/Centos_59_Working_Vault_Repo_file-1921-articles yum update Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile  * epel: fedora-archive.ip-connect.vn.ua Traceback........
  • linux cp and mv will not overwrite due to alias!


    This through me for a loop when I would do a cp -rf or mv -f nothing would get overwritten even if piping y or yes to the command. Type alias and you'll see why: alias cp='cp -i' alias l.='ls -d .* --color=auto' alias ll='ls -l --color=auto' alias ls='ls --color=auto' alias mv='mv -i' alias rm='rm -i' The -i is a safeguard against messing things up but however does mess things up worse when you know what........
  • kdenlive - No LADSPA plugins were found! Check your LADSPA_PATH environment variable. [producer_xml] failed to load transition "qtblend"


    This happens if you are running a kdenlive script from the shell of a remote machine without using SSH "-X" forwarding and it will also cause any areas where you write text to be a white screen for that duration.   melt FusionFestival.kdenlive No LADSPA plugins were found! Check your LADSPA_PATH environment variable. [producer_xml] failed to load transition "qtblend" [producer_xml] failed to load transition &q........
  • /usr/bin/supermin-helper exited with error status 1. To see full error messages you may need to enable debugging. See http://libguestfs.org/guestfs-faq.1.html#debugging-libguestfs at /usr/bin/virt-list-partitions line 177.


     virt-list-partitions kvmusertest.img /usr/bin/supermin-helper exited with error status 1. To see full error messages you may need to enable debugging. See http://libguestfs.org/guestfs-faq.1.html#debugging-libguestfs at /usr/bin/virt-list-partitions line 177. #solution update-guestfs-appliance........
  • Centos 5.9 Working Vault Repo file


    Centos 5 is not supported running yum will produce an error like this: YumRepo Error: All mirror URLs are not using ftp, http[s] or file.  Eg. Invalid release/ removing mirrorlist with no valid mirrors: /var/cache/yum/base/mirrorlist.txt Error: Cannot find a valid baseurl for repo: base Solution - Update this file CentOS-Base.repo   # CentOS-Base.repo........
  • How to backup entire computer Linux Mint Ubuntu with tar


     sudo tar --ignore-failed-read  -czvf mycomputer-backup.tar.gz --exclude=/home/otheruser/* --exclude=/proc/* --exclude=/sys/* / Note the --exclude clauses and modify/add according to your needs........
  • tar how to ignore failed reads and not exit


    This is an important feature a failed read can genuinely occur if a temporary file has been removed or if you try backing up a sysetm file in /proc /sys (which you shouldn't really anyway). The way to fix this is the following switch: --ignore-failed-read   Example: sudo tar --ignore-failed-read  -czvf mycomputer-backup.tar.gz --exclude=/home/otheruser/* --exclude=/proc/* --e........
  • kdenlive titles/text renders as white screen when using .sh script


    When using the .sh script the rendering doesn't work after an upgrade of related packages to kdenlive.   kdenlive (kdenlive:amd64 (4:17.04.1+git201705191233~ubuntu16.04.1)) with affine or composite transitions was fine but is now broken during the time of transition it is just a white screen. The previous version was fine: kdenlive:amd64 (4:17.04.1+git201705191233~ubuntu16.04.1 But now I can't find it or install it:........
  • Wine uninstalled broken on Linux Mint


    Solution: Aptitude is very smart and fixed the issues it was because of nvidia cuda and opencl and nothing else suggested or hinted this using apt sudo aptitude install wine The following NEW packages will be installed:   ocl-icd-libopencl1{ab} ocl-icd-libopencl1:i386{ab} wine wine1.6   wine1.6-amd64{a} wine1.6-i386:i386{a} The following packages will be REMOVED:........
  • ffmpeg trouble concatenating similar but different files


    When things go wrong your video is basically unplayable or the first video plays fine and then freezes when moving on to the next.  Generally if both videos weren't produced with the exact 100% same settings you will have issues.  You can try the basic concat but it often won't work right. Solution for me: My example uses 3 videos in total so "n=3"  and a=1 to include audio. ffmpeg -threads 12  -i file1.mp4 -........
  • 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........
  • Linux Mint USB Kernel Tainted and Locked Port/Dev File


    Essentially a program I was running for mining did not terminate properly with Ctrl+C it is listed as defunct and cannot be killed, kernel is tainted and normal tricks to disable the port are impossible the dev and sys entries for the device cannot be browsed or interacted with in any form without a lockup of the request.  The only solution is to reboot due to the kernel taint as far as I can find so far.   [1130246.811056] INFO: task minerd:21861 blocked for more th........
  • 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........
  • rsync run as root sudo without password


    This is a common issue, what if a issue shouldn't have root but you want to use that user to make a full backup of a system?  They of course need root access. You can actually just give them passwordless sudo access to rsync in /etc/sudoers: sudo vi /etc/sudoers yourusername ALL = NOPASSWD: /usr/bin/rsync   Here is how you would execute rsync: The key thing for the remote host is to........
  • process_usershare_file: stat of /var/lib/samba/usershares/dump failed. Permission denied - samba error solution


    [2017/06/12 21:14:04.991169,  0] ../source3/param/loadparm.c:3259(process_usershare_file)   process_usershare_file: stat of /var/lib/samba/usershares/dump failed. Permission denied Issue was the parent directory needed chmod 755........
  • Openshot 2.2 is very unstable always crashing in Linux Mint 18.1!


    Jun  1 15:45:42 videoeditor-desktop org.mate.panel.applet.MintMenuAppletFactory[1882]: project_data:INFO Missing folder chosen by user: Jun  1 15:45:42 videoeditor-desktop org.mate.panel.applet.MintMenuAppletFactory[1882]: project_data:INFO Removed missing file: MAH02949.MP4 Jun  1 15:45:57 videoeditor-desktop org.mate.panel.applet.MintMenuAppletFactory[1882]:      ui_util:WARNING Icon theme media-playback-start not found. Will use backup........
  • 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........
  • MySQL Add multiple IPs for remote user including root howto


    To grant the IP 192.168.2.4 to user mysqlguy GRANT ALL ON *.* TO 'mysqlguy'@'192.168.2.4'; To allow any IP for mysqlguy just use the wildcard % character GRANT ALL ON *.* TO 'mysqlguy'@'%'; Also note it is normal and fine to have multiple entries in the mysql table.........
  • cPanel error Access denied for user 'root'@'localhost' when adding remote MySQL IP address solution


    Error while connecting to MYSQL: (XID 4ea7s9) Access denied for user 'root'@'localhost' (using password: YES) at /usr/local/cpanel/Cpanel/Mysql.pm line 181 Solution This error occurs because the /root/.my.cnf has the wrong/outdated password for MySQL root user.  Simply edit /root/.my.cnf with the correct user. This normally happens if you update outside of cPanel.........
  • phpBB3 slow and internal dummy connection


    Using Apache 2.2 and PHP 5.6 PHPBB3 is very slow to respond.  Actually for some reason it takes so long to even register a log entry in access_log as in several seconds or a few minutes later it shows up in Apache.  All other vhosts and Apache access stops working and freezes until the request to access PHPBB3 slowly completes. It seems to randomly be slow if you stop using it whether for posting or reading the forums.  I've migrated to different machines including........
  • ssh forward multiple ports in the same connection and command even works with NAT!


    You can actually just pass multiple "-L" statements to achieve this. An example is as below: ssl -L 80:192.168.10.5:80 -L 443:192.168.10.5:443 -L 2068:192.168.10.5:2068 -L 8192:192.168.10.5:8192  user@remotehost.com   The above essentially is saying forward ports 80,443,2068,8192 to the remote IP of 192.168.10.5 (even though it is behind NAT).  Essentially SSH will do the NAT part even if the........
  • Avocent DSR8020 KVM/IP - Network Connect Error - Solution


    This error is commonly due to Java security or TLS settings but there is a second issue with forwarded ports that also causes it.   1. Java Security/TLS Settings issue: This article has the solution to change them all in Linux automatically 2. Port Forwarding Issue if your Avocent DSR is behind NAT/private IP........
  • ecryptfs errors


    ecryptfs-mount-private Enter your login passphrase: Inserted auth tok with sig [ee16d84] "into the user session keyring mount: No such file or directory" [  156.118113] ecryptfs_mount: kern_path() failed [  156.118431] Reading sb failed; rc = [-2] [  164.233055] traps: mate-notificati[3472] trap int3 ip:7f43d7002c13 sp:7fff162c6600 error:0 [  166.017061] ecryptfs_mount: kern_path() failed........
  • Migrating from Linux Mint 17.2 mdadm RAID array to a new one (because I upgraded to larger drives).


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  • Linux Ubuntu Nvidia GT430 Lockups/Errors/Freezes NVRM: os_schedule: Attempted to yield the CPU while in atomic or interrupt context


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  • Openvz Container IP not working suddenly Solution


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  • Linux Out of Memory OOM Object Killer Solution "Out of memory: kill process 1955 (sshd) score 81 or a child"


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  • MySQL Out of Range Solution for DATETIME field


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  • Understanding /etc/aliases from sendmail when using with postfix or other MTA's


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  • Ubuntu 9.04 Crash


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  • Installing Webmin & Enabling SSL


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  • Virtualmin/Webmin Postfix Error: The status of your system is being checked to ensure that all enabled features are available, that the mail server is properly configured, and that quotas are active ..


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  • SSH delay problem UseDNS and disabling GSSAPI does not help


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  • Cygwin and crontab backups via ssh/scp/rsync


    Install the "Editors" and "Net" groups that will give you rsync, ssh, ssh-keygen and cron. The trickiest thing that I keep forgetting about each time is you have to run "cron-config" which adds the cron service to Windows, and without doing that obviously no cron jobs will be run thus making automatic backups impossible. Warning about rsync/cygwin and using the -a archive switch. It's a good thing I caught this because it doesn't work ri........
  • rsync preserve attributes, permissions/ownership and times without being root non-root user


    One of the purposes of rsync is to backup whole filesystems and archive them but how can you do that properly and restore things to normal if all permissions and ownerships are not preserved from your root filesystem? It's not desirable to have everything running as root, especially not just for an rsync. The Easy rsync preserve permission solution for non-root users sudo is the answer and all you have to do is edit /etc/sudoers At the end o........
  • Ubuntu/Debian DRBD 8.0 Setup Guide


    I've only used it on Centos, so I thought I'd make a quick Debian guide: Install the DRBD Package apt-get install drbd8-utils Reading package lists... Done Building dependency tree       Reading state information... Done The following packages were automatically installed and are no longer required:   libswfdec-0.8-0 Use 'apt-get autoremove' to remove them. The following........
  • yum in Centos 5/Xen halts and exits suddenly


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    You need to jailbreak your phone and inside Cydia you'll find "PushMod" which will allow you to set your mail check time to 1 minute instead of 15-minutes. This is a great mod and has saved me a lot of stress and frustration, the lack of Blackberry style "free push service" makes iPhone less attractive, but this solves that. Apple needs to make mobileme free and have a Blackberry style chat network to compete, I'm not willing to pay for something Blackberry........
  • Why Apple should thank the jailbreakers and not patch/stop the jailbreaking exploits


    First of all, the iPhone is crippled in many ways, but most of my complaints about functionality have been addressed through the jailbreak, I can run apps in the background of my choosing, I can install a terminal, acccess my phone through SSH and SCP and so much more. It even addresses the 15 minute e-mail problem, I installed a program called "PushMod" and now set the checking time to just 1 minute. Apple should really thank the developers for this gift, it ma........
  • iPhone 3GS Jailbreak Information & Benefits


    Truly, the only way to unleash the capabilities and customization abilities of iPhone are to jailbreak, it's not just for hackers anymore. A few days ago someone by the named of "geohot" released a single click application called "purplera1n", which does the entire operation smoothly and seamlessly. In our case, the first time it went as far as "done, wait for reboot" on our Windows machine and for minutes we waited and saw the pic on the iPhone w........
  • iPhone 3GS 32GB "Harsh Review"


    Yes, I admit I finally got bitten by the hype as much as I can usually see through it all.  Keep in mind this review is of the "stock" phone, no jailbreaking yet which is what really unleashes the customizability and why I bought iPhone. I had better things to say about this phone before buying it, and it is a great phone, perhaps the best on the market by far, if not because of the Mac OS port onto the iPhone and all the apps, etc, etc. With that said........
  • iPhone has no password/wand manager saving feature in Safari Web Browser


    I kind of expected this feature to be there in some form, to stay ahead of the pack Apple needs to stay on top of this.  User's of HTC's Android smart phone which uses a Linux based OS with Google's power behind it, note that you can save passwords in the browser on that phone. Apple needs to continuously evaluate the needs in its core apps and make sure the features are cutting edge and top notch, if other phones come out with some of these seemingly small but essential features........
  • Apple iPhone 3GS and predecessors are leading a revolution


    As much of a computer nerd as I am, I'm usually a late adopter to technology for a few reasons.  I feel most new hyped technologies and electronics are mainly fads, and I'm also cheap. Adopting later means you avoid the bugs, kinks and most importantly pay the lowest price, that's me being cheap again :) I never read much about the iPhone but I saw all the hype around it and until recently I wasn't a big fan of anything Apple until a few years ago I realize........
  • Nokia N97 review, feedback and complaints


    I've had an old Blackberry for a few years and I was ready to spend some serious cash on a nice Nokia.  I love the idea of the Linux based Symbian S60 OS, so I was looking at phones like the E63, E71 (both are basically the same, at least CPU/screensize although E71 is thinner, has a 3MP camera, has GPS, and has dedicated buttons to adjust the volume). Then I heard about the N97 and what a revolution it was supposed to be and it was even compared to iPhone.  To........
  • OCFS2 crash


    When trying to even cd or ls the mounted OCFS2 partition it crashes.  I think this is a combination of VMWare Server's problem and the way I mounted and symlinked to it. More than anything this shows the problem and lack of forsight with VMWare, but also that OCFS2 is easily crashed if you do strange things. Output of /var/log/messages for OCFS2   Apr 10 15:57:45 localhost kernel: [84331.691258] Modules linked in: vmnet vmci vmmon ocfs2_stac........
  • Samba SMB Error - Server not using user level security and no password supplied. tree connect failed: NT_STATUS_WRONG_PASSWORD


    Server not using user level security and no password supplied. tree connect failed: NT_STATUS_WRONG_PASSWORD That happens when trying to use smbclient to connect to a share.  The weird thing is that I can authnenticate just fine from Windows XP. It is partially my mistake, I forgot this share does have a password.  I've tried authenticating with the correct user and also with "Guest" because this works in Windows.  In Linux I ........
  • Viewing and Connecting to an SMB Samba Share on Windows/Linux/Unix


    This will give you the basic info needed to browse and connect to Samba shares from the command line.  From the GUI of Gnome or KDE etc, it is pretty standard and straight forward.  However, I've found very little guides on how to do it from the command line and if you're like me, a nerd who prefers command line for its simplicity and for remote use, this is the way to go. First get a list of all the Samba/SMB shares on the target. smbclient -L hostname........
  • SSH Problem User username from 127.0.0.1 not allowed because not listed in AllowUsers


    User username from 127.0.0.1 not allowed because not listed in AllowUsers What's going on?  The user was created properly, it has been defined as having a shell entry and the entry for /etc/passwd and /etc/shadow is set just fine. This is a new and very smart/secure feature of SSHD.  It is simple and yet effective, but also very annoying if you didn't know about it being implemented and that hand editing of /etc/ssh/sshd_config is required to allow a newly add........
  • Writing/Burning a data CD-R/DVD-R or DVD+RW in Unix/Linux


    There's a lot of outdated information and confusion for system administrator's out there. One annoying task for many an Administrator has been backing up data in Linux.  You don't need any GUI tools such as K3B or GnomeBaker.  Both are excellent tools but for veteran command line users working remotely, using the keyboard is a great and possibly automated way to save yourself pain and hassle. At a later date we'll cover how scripting can automatically backup certain........
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