/ - 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........
  • What is /dev/pts and why do we need it in Linux?


    A quick check in /dev/pts shows a lot of entries but what are they for?:  ls /dev/pts 0  10  12  14  16  18  2   21  23  25  27  29  30  32  4  6  8  ptmx 1  11  13  15  17  19  20  22  24  26  28  3   31  33  5  7  9 Basically they are pseudo-termi........
  • Supermicro IPMI / KVM / BMC Remote Console Screen Resizing Issue - Window Cut Off Solution


    It could just be my specific Java but other KVM/IP works ok on my machine but with Supermicro's IPMI for some reason the console window doesn't resize and even putting it in full screen leaves the window cut off as shown below: As you can see above the screen is cut off you can't see the "I agree" on the right side. The window resi........
  • VMWare ESXi 6.7 SSH/PowerShell CLI Commands


    [root@localhost:~] BootModuleConfig.sh          echo                         host-ind                     nfcd                   ........
  • [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........
  • Linux How To Free Wasted Memory RAM in Buffers


    We all know Linux is known for good memory management but is it really?  It seems all on its own with hardly anything running that you can come back in days or weeks and find that almost all of your RAM is used! And many will say "no don't worry it's buffers for optimization" but it doesn't seem to help because what is in buffers is not available to use for new programs running or ones that allocate more RAM as far as I can tell. The reason I know........
  • 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........
  • 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........
  • OpenVPN cannot ping remote IP routing loop issue after connecting


    Sometimes if you have a very basic configuration OpenVPN on the client side for some reason sends all traffic to the OpenVPN server IP through the tun0 which is of course impossible and creates a block or routing loop.  This is because you need to use your normal ISP/LAN gateway to hit the OpenVPN server if it is remote/offsite as is usually the case.  So if you are connected to the OpenVPN through say a tun0 device and your routing is set to connect to the OpenVPN&nbs........
  • 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........
  • mdadm how to stop or start a check


    It's fairly simple to start or stop a check but I do wish mdadm's command had this built in.  Sometimes it will do a check at the worst time causing the server to crawl to a halt. Stop check on md126: echo idle > /sys/block/md126/md/sync_action Start check on md126: echo check > /sys/block/md126/md/sync_action  ........
  • vzquota : (error) Quota on syscall for id 4532: No such file or directory vzquota on failed [3] OpenVZ Error and Solution


    Starting container... vzquota : (error) Quota on syscall for id 4532: No such file or directory vzquota on failed [3]   Solution vzquota drop 4532 Then start the container and it should work.  It actually happened after migrating the VPS manually to ano........
  • 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........
  • MySQL Adding New Field to Existing Database Table


    ALTER TABLE existingtable ADD newfieldname VARCHAR(255);........
  • MySQL How To Add New Field Column To Existing Table


    ALTER TABLE thetable ADD newfield VARCHAR(255) It's very simple just specify "the table" and then the newfield type........
  • 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........
  • rsync specify alternate port non-standard port than 22


    It is not obvious but the rsync --help  rsync --help|grep port      --port=PORT             specify double-colon alternate port number --port does not do anything at all actually for some strange reason it still uses 22 You have to specify a manual ssh command to make it work: -e 'ssh -........
  • ffmpeg Linux Mint download, compile and install howto


    #if you have nvidia make sure you install the nvidia-cuda-toolkit so hardware acceleration can be used wget http://ffmpeg.org/releases/ffmpeg-3.3.2.tar.bz2 tar -jxvf ffmpeg-3.3.2.tar.bz2 cd  ffmpeg-3.3.2/ ./configure --disable-yasm install prefix            /usr/local source path              ........
  • USB 3.0 External HDD Enclosure Seagate UAS problems - [sdd] tag#1 CDB: Write(16) 8a 00 00 00 00 01 70 04 08 68 00 00 00 08 00 00


      This is a 8TB Seagate external USB 3.0 device apparently newer kernels use a module called "UAS" instead of "USB Storage" which causes issues as a lot of devices are not properly supported in UAS mode by the kernel driver.  The solution some say is to disable UAS specifically for your USB device but I'd rather just disable UAS altogether.   Solution blacklist UAS: *do not do this it does not work and just causes your USB 3.0........
  • Linux Mint Intel Screen Tearing Horizontal Line Solution Fix


    sudo mkdir -p /etc/X11/xorg.conf.d/ sudo vi /etc/X11/xorg.conf.d/20-intel.conf   Type "i" and enter the following: Section "Device"   Identifier      "Intel Graphics"   Driver          "intel"   Option          &........
  • use ffmpeg to watermark videos if mencoder/bmovl fail


    If you have this problem: http://realtechtalk.com/mencoder_bmovl_error_vf_bmovl_Unknown_command_Ignoring_-1860-articles Then ffmpeg is for you.  Go here if you are using Linux Mint and cannot find or install it to use an external PPA........
  • 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........
  • How to verify SSL SHA-1 Certificate Fingerprnit Signature of your mail/web server to avoid hijacking/man-in-the-middle attacks


    This is especially helpful if you run your own servers.  If you are presented with an error message or warning that the signature has changed or does not match the IP/domain you are connecting to you always want to verify manually. So your e-mail/web client will show you an SHA-1 fingerprint like this: "Could not verify this certificate because the issuer is unkown" or other reasons such as a mismatch in IP/domain. It will also show you........
  • PayPal Subscription Howto Creation Automatic Payments Manual


    An easy way to pay companies and friends/family since PayPal does not have an option when sending money to make it a subscription: "business" = The e-mail or PayPal ID of the person/organization to pay to. a3 The recurring amount "eg. 115" will be 115 USD p3 The time period (eg. 2) t3 Unit of time period m=monthly,w=weekly,y=yearly item_name = "the note/product service reason you are paying ha........
  • Linksys PAP2T No Dialtone and Cannot Hear Caller


    I have two lines on my PAP2T and the only thing that solved this problem rather instantly was to change the line with the problem to using port 5060 instead of 5061 (so both lines are using port 5600). Note that I am not forwarding either port in my router either. Some of the symptoms of this problem for me were the following: No dialtone or it would take several tries. You answer a call but the phone keeps ringing (takes a few times t........
  • Linux Mint/Ubuntu/Debian Window Controls Missing Solution


    If Linux Mint 17 or other has no window buttons/controls you can do the following from terminal: marco --replace& Sometimes it can be fixed if you go to your themes/appearance and choose a new one but in the case like mine where Compiz is installed but not running/working then that fix will not work and will require the marco command above. What if you can't type in a terminal Window? If you close........
  • Linux Mint Network Manager Connection Disconnect Option Grayed Out


    This is a real pain because I had to manually unplug ethernet cables for network testing or to use an alternate network or guarantee physical access to one network segment is cut off.  For some reason this happened after I killed dbus because it was confused and blocking packets thinking they were coming from the wrong interface since eth0 and eth1 both had the same subnet and gateway. I eventually did a "service network-manager restart" but the option was........
  • 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........
  • Firefox errors Unable to generate public/private key pair. (Error code: sec_error_keygen_fail)


    Your firefox is out of date if you get errors like below:   Secure Connection Failed                                                        ........
  • HP Procurve Switch 2824 CLI Telnet Experience , Guide and Tutorial


    telnet 192.168.1.54 ------------------------------------- ProCurve J4903A Switch 2824 Software revision I.10.77 Copyright (C) 1991-2009 Hewlett-Packard Co.  All Rights Reserved.                            RESTRICTED RIGHTS LEGEND  Use, duplication, or disclosure by the Government is subject........
  • esniper and curl errors https://signin.ebay.com/ws/eBayISAPI.dll?SignIn: Couldn't connect to server: couldn't connect to host


    I kept thinking it was esniper but somehow my bash settings have a preset proxy that was creating the issue. https://signin.ebay.com/ws/eBayISAPI.dll?SignIn: Couldn't connect to server: couldn't connect to host curl manually to any URL is the same: curl: (7) couldn't connect to host Run curl with -vvvvvv mode to see the issue: curl -vvvvvvvvvv http://realtechtalk.com * About to c........
  • Samsung Galaxy Note Upgrade/Update Experience from 4.0.4 with aftermarket ROMs


    It really seems that 4.4.4 is not ready or stable for the i717 yet and this makes sense since it takes a lot of work/development and testing to get the factory stock ROMs working well.  In the end I used the 4.1.2 based Blackstra BlackJelly because it was fast, stable and just works and feels great.  The aftermarket support is great but many devs are focussed on adding features and customization that most of us don't want or need rather than getting things smooth and stable.........
  • 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........
  • CPanel Link to all of the command line options


    <p>CPanel says you can access 98% of the functions through CLI which experienced Unix/Linux admins prefer for simplicity and for scripting.&nbsp; I've never found CPanel easy to use from the admin panel, it seems everything is hard to find and a simple task becomes a series of hunts.</p> <p>So for people like me here's the list: <a href="http://cpanel.net/system-administrators/command-line-scripts/">http://cpanel.net/system-administrators/command-line-scrip........
  • PayPal Convert BuyNow Button to Plain HTML Link


    Say if you have a form/button like this:          <form method="post" action="https://www.paypal.com/cgi-bin/webscr">                 <input type="hidden" value="_s-xclick" name="cmd" /> <input type="hidden" value="THEBUTTONID" name="hosted_button_id&quo........
  • Windows 2008 Server Trial How To Activate & Extend the Trial


    To activate your Windows 2008 server trial which gives you 180 days: Start -> Right Click (My Computer). Click "Activate Windows now" To renew your license for 6 days (can be done 3 times): Start -> Type this command: slmgr.vbs -rearm Wait a few minutes until it says it is successful (unless you get that message it has not worked or been done)........
  • Howto Restore Acer Aspire E1-531-4406


    Hit Alt + F10 before the system boots and you'll boot into the recovery drive and be able to restore your system, of course note that all of your data will be wiped out.........
  • virtio KVM drivers download location


    http://realtechtalk.com/downloads/virtio-win-0.1-74.iso Current Direct stable URL from Fedora: https://fedoraproject.org/wiki/Windows_Virtio_Drivers Direct Downoad of Stable Virtio: https://fedorap........
  • cPanel VPS Server Cannot Login as root


    I was worried the server was hacked, I was logged in already as root but couldn't login to CPanel or a new SSH session.  I even reset the password from the shell and it did not work still. The reason is CPanel Hulk, it detected a brute-force attack so it locked down the root account entirely even from the correct password.  According to cPanel the best way around this is to whitelist your IP.........
  • MySQL How to add a field/column using alter


    ALTER TABLE yourtable ADD COLUMN info VARCHAR(255)........
  • wget test without actually downloading howto


    user the "--spider" switch and you can see what it would do. wget -r --spider dontryrealtechtalk.com........
  • KVM on Centos 6.3 cannot boot FreeBSD 9.2 AMD64


    <p>On the same OS with the same kernels basically I cannot boot FreeBSD installer, I&nbsp;believe the issue is the host CPU.</p> <p>One host runs an Intel and works, while an Opteron 2373 does not work despite suggestions from this thread: <a href="http://149.20.54.209/showthread.php?t=36761">http://149.20.54.209/showthread.php?t=36761</a></p> <p>I've tried cpu options like &quot;kvm64&quot; &quot;Opteron_G3&quot; and none........
  • vzquota : (error) Quota on syscall for id 42131: No such file or directory vzquota on failed [3]


    Starting container... vzquota : (error) Quota on syscall for id 42131: No such file or directory vzquota on failed [3] Solution cd /var/vzquota mv quota.42131 quota.42131-disable  vzctl start 42131 Starting container... Initializing quota ... Container is mounted Adding IP address(es): Setting CPU units: 1000 Container start in progress...  ........
  • Sendmail Gmail.com blocking


    relay=alt4.gmail-smtp-in.l.google.com. [74.125.136.26], dsn=4.0.0, stat=Deferred: 421-4.7.0 [      10] Our system has detected an unusual rate of This is strange because the mail server IP is not blacklisted anywhere and the IP itself has not been used for years and this server is clean and has only sent a few e-mails to gmail.com in its entire time. I wonder if this is a legacy block on a whole range of IPs as punishment for others in the block........
  • LSI MegaRAID Adventures, Guide and HowTo


    LSi Megaraid At first it was configured as a RAID 0, then I deleted the Virtual Disk Group. I thought both drives would be shown and detected in Linux as sda and sdb but it actually shows nothing. To make them work you have to hit Ctrl+R before the system boots (when prompted) and create a Virtual Disk Group.  In my case I created each one as RAID 0 (with a single drive only) as I just wanted JBOD but there is no such option or default in these Dell Pe........
  • mkdir(): Too Many Links - The Solution and Problem in ext3 filesystems


    The error itself "mkdir(): Too Many Links" is not very useful, but I'll translate it into plain English. It means you've reached the filesystem's limit of how many directories can be created in a single directory. In this case for ext3 the limit is 32000 and it was exceeded. What's the solution?  The simple solution is to move those directories into more subdirectories possibly sorting them by date, alphabet or numerically. ........
  • rdesktop/Terminal Server Client Send Ctrl+Alt+Delete Howto


    The program itself catches it, just make sure it's actually focused on rdesktop and it sends Ctrl+Alt+Delete to the remote machine and not the local.........
  • Country List Names in HTML Select From


    This is useful for developing a lot of applications, I'm putting it here to keep it handy for myself and hopefully others:   <select name='country'><option value=Choose>Choose Country</option><option value=CA>Canada</option><option value=JP>Japan</option><option value=US>United States</option><option value=GB>United Kingdom</option><option value=AF>Afghanistan</option><option value=AL&........
  • Directadmin error/** Found 7 pre-existing rpmdb problem(s), 'yum check' output follows: e2fsprogs-devel-1.41.12-3.el6.i686 has missing requires of e2fsprogs-libs = ('0', '1.41.12', '3.el6') e2fsprogs-devel-1.41.12-3.el6.i686 has missing requires of l


    Solution To The Following: yum -y install zlib-devel yum -y install e2fsprogs* *** Cannot find /usr/include/et/com_err.h.  (yum install libcom_err-devel) *** Installation didn't pass, halting install. Once requirements are met, run the following to continue the install:   cd /usr/local/directadmin/scripts   ./install.sh Common pre-install commands:  http://help.directadmin.com/it........
  • How to log all PHP based E-mails for abuse


    Step #1 - Create Wrapper Script vi /usr/local/bin/phpsendmail #!/usr/bin/php <?php //changed by realtechtalk.com to make the log readable /**   This script is a sendmail wrapper for php to log calls of the php mail() function.   Author: Till Brehm, www.ispconfig.org   (Hopefully) secured by David Goodwin <david @ _palepurple_.co.uk> */........
  • Centos 6 RTL8111/8168B r8169 link up and down error solution/fix


    02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03) For whatever reason it seems the r8169 driver that ships and has shipped with most Linux distros for years is still flawed and does not work properly on these cards, causing 100mbit connectivity when it should be 1gbit and even worse, causing random network dropouts.  The r8169 driver in Linux kernels is simply not meant to be used on th........
  • How to install GRUB to the MBR of a disk image.


     cat | grub --device-map=/dev/null Now pay close to the attention of the beginning. Type: "device (hd0) VPS.img" this is telling what hd0 will be to GRUB and we're telling it the disk image file "VPS.img" in the current directory is hd0, you can specify alternate paths and image names of course.     GNU GRUB  version 0.97  (640K lower / 3072K upper memory)  [ Minimal BASH-li........
  • mdadm: /dev/sdb1 not large enough to join array solution


    mdadm --manage /dev/md1 --add /dev/sdb1 mdadm: metadata format 00.90 unknown, ignored. mdadm: metadata format 00.90 unknown, ignored. mdadm: metadata format 00.90 unknown, ignored. mdadm: /dev/sdb1 not large enough to join array md1's first primary member /dev/sda3 has 57394 cylinders while the /dev/sdb1 has 57393 (1 less cylinder) which is why it won't work.  fdisk -l /dev/sda3 Disk /dev/sda3: 47........
  • Linux Ubuntu Nvidia GT430 Lockups/Errors/Freezes NVRM: os_schedule: Attempted to yield the CPU while in atomic or interrupt context


    I'm running Ubuntu 10.10 with Asus NVIDIA GT430 2.6.35-32-generic-pae #65-Ubuntu SMP Tue Jan 24 14:06:16 UTC 2012 i686 GNU/Linux Nvidia binary driver: 260.19.06 The screen sometimes completely freezes and locks up or everything starts going very slow: [1903398.100007] NVRM: os_schedule: Attempted to yield the CPU while in atomic or interrupt context [1903402.373210] NVRM: Xid (0001:00): 53, CMDre 00000000 00000080 00000000 00000005 00........
  • Xen non-HVM container won't work/boot anymore


    One of my test Centos 5 containers was on a partition that filled up and it threw all sorts of errors and stopped responding but now I can't boot it again anymore. All the console shows is the Linux Penguin on the top left corner and the xm console says "usbcore: registered new driver hub" and has halted there. Centos 5 Xen container stuck/frozen won't boot on "usbcore: registered new driver hub" Another great way of troubleshooting is booting fro........
  • MySQL Replication/Dual-Master vs Clustering


    Many people aren't aware but recently Dual-Master Replication setups have become increasingly popular.  That's because you get similar features and benefits of having a full-blown cluster (difficult to setup and maintain and requires I believe 3 servers just as controllers). With a dual-master you just have a different off-set for the keys and you should be good, but of course there is the chance that at some point replication will halt because of an unexpected or unforseen error........
  • Linux Realtek Gigabit NIC huge/high latency problem after sleep?


    That is pinging to the gateway IP on the same switch, the same IP is pingable externally without any problems which makes me think the switch is fine. 64 bytes from 55.55.55.55: icmp_seq=4 ttl=255 time=1.07 ms 64 bytes from 55.55.55.55: icmp_seq=1 ttl=255 time=3536 ms 64 bytes from 55.55.55.55: icmp_seq=2 ttl=255 time=2536 ms 64 bytes from 55.55.55.55: icmp_seq=3 ttl=255 time=1536 ms 64 bytes from 55.55.55.55: icmp_seq=8 ttl=255 time=1.20 ms 64 by........
  • 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


    yum exits in the middle The problem is this VPS seems to be an OpenVZ template from HyperVM.  The only way to make it work was to disable i386 packages since this was an x64 kernel.  That shouldn't be necessary but it was the only way to make yum stop quitting after the first package or two.  I couldn't find any issue by checking the logs either. echo y|yum install vim-minimal telnet expect jwhois net-tools slocate iptables elinks gawk L........
  • Linux Kernel Boot Black Screen of Death Freeze/Halt Solution


    This happens on some systems due to a video issue with Intel Videocards, after you see the kernel load you may see almost immediately that you get a black screen. The following kernel parameters usually solve it: nomodeset i915.modeset=0 xforcevesa some people just use "nomodeset" and others use "i915.modeset=0".  I think nomodeset may also do the same for each video driver so it may imply i915.modeset=0 anyway but I am not sure.........
  • GNOME/Ubuntu how to navigate without a keyboard


    The most basic is the start menu, which is accessed with Alt+F1........
  • Shutdown/Power/Halt In Debian/Ubuntu/Centos Guide Systems Doesn't Work


    Different distributions such as Debian and Centos behave differently when trying to shutdown your system. shutdown -H now on Debian does not do what you'd expect.  The system won't power down, it will halt and do everything but power down. shutdown -PH now will do the job though (actually power the system off).  This is important to test especially if you are not near the system.  If you just use -P it forcefully shuts off which is not........
  • md: kicking non-fresh sda1 from array! - fix/solution


    md: Autodetecting RAID arrays. md: autorun ... md: considering sdb1 ... md:  adding sdb1 ... md:  adding sda1 ... md: created md0 md: bind<sda1> md: bind<sdb1> md: running: <sdb1><sda1> md: kicking non-fresh sda1 from array! md: unbind<sda1> md: export_rdev(sda1) raid1: raid set md0 active with 1 out of 2 mirrors The md0 raid kicked sda1 ou........
  • Realtek r8169 1gbit/1000mbit NIC/Ethernet Goes Down/Halts on Large File Transfer/Heavy Network Usage


    This is obviously a bug in the r8169 kernel module and it seems to affect a lot of people.  I upgraded to the latest kernel and hope this won't happen anymore, as it is a very serious error.  This is especially serious for those who are running servers with this chipset, who can afford for the NIC to randomly go off-line for no apparent reason?   [655548.189113] type=1505 audit(1277067560.902:5): operation="profile_load" name="/usr/bin/freshclam&q........
  • Use rcconf to edit startup/init.d/init scripts on Debian/Ubuntu based distributions


    I've never understood how to enable and disable services for different run levels in Debian based distros, it's just weird, annoying and doesn't make sense.  I much prefer chkconfig from RHEL. Just install the package called 'rcconf' and be done with it.  rcconf makes things easy for you. apt-get install rcconf Reading package lists... Done Building dependency tree        Reading state information... Done........
  • How To Set DHCP/Static IP Address in Centos/RHEL/Fedora & Debian/Ubuntu/Kubuntu/MEPIS Set DHCP/Static IP Address


    Basically the two main types of distros are Debian and RHEL/Centos based.  I'm just going to give a quick overview of how the configuration of IP interfaces works in Debian/Centos based distros. *Just one thing to remember, when setting IPs statically you have to manually specify a DNS server in /etc/resolv.conf (since DHCP is what normally does it automatically) Debian/Ubuntu/Kubuntu/MEPIS The IP (DHCP &........
  • SSH Automatic/Passwordless Logon - Setup Public Key Encryption In Single Command


    This is a very simple solution, but most guides out there make you login twice (once to scp the key) and once to put the key in authorized_keys.  There's no need for that.  If you don't already have a ~/.ssh/id_rsa.pub just type "ssh-keygen -t rsa" and keep hitting enter until it's done :) Just use this code to easily enable passwordless login with SSHD key=`cat ~/.ssh/id_rsa.pub`;ssh user@192.168.5.25 "echo $key >> ~/.ssh/auth........
  • rsync halted froze Out of memory: kill process 7559 (rsync) score 635 or a child Killed process 7559 (rsync)


    Out of memory: kill process 7559 (rsync) score 635 or a child Killed process 7559 (rsync) I was surprised to see this in my dmesg when my rsync backup suddenly stalled/stopped. This system has 3 gigs of RAM and lots of free memory so I don't understand what is happening.   rsync invoked oom-killer: gfp_mask=0x200d2, order=0, oomkilladj=0 Pid: 7600, comm: rsync Not tainted 2.6.24.2 #83  [<c014990e>] oom_kill_pr........
  • MySQL TEXT field size length limit reminder, don't truncate your data!


    I thought there would be an error message or warning from MySQL in the case that the text you submit is greater than the allowed limit based on the field. So essentially I submitted text that was about 120,000 characters long, whereas the limit of TEXT is just 65,535 characters!  I almost lost half of my data/what I typed without knowing it! I just altered the field type in my database from TEXT to LONGTEXT.  I can't see how LONGTEXT wouldn't be long enough for MOST........
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    The folder I was trying to archive is about 72GB, but much like rsync at about 17GB it chokes because of the filesize.  What's with so many common and essential Linux tools having such limitations?  I guess it is likely that the authors never wrote their code with the idea that files would be so large but it's still very annoying.  It's important to stay on top of these limitations on production servers because I didn't realize what happened until I checked the file with "........
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    Here are the results, it is Sempron 3000+ AMD Mobile, 500Gig HDD, 512MB RAM with shared ATI Radeon graphics.      #    #  #    #  #  #    #          #####   ######  #    #   ####   #    #    #    #  ##   #  #   #  #&nb........
  • Great sound tutorial


    Great sound tutorialThis is great if you need users to be able to start/stop playing sound on your page with the click of a button. http://www.smartwebby.com/Flash/sound_button.aspHere's a simple one except that it doesn't do rollovers. http://www.flash-here.com/tutorials/flash_play_sound.html I actually could not get the rollovers to work using the other tutorial so it is either a mistake on the webmaster's part or........
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    Changing field names[quote:91ea6831b6]ALTER TABLE [u:91ea6831b6]table_name[/u:91ea6831b6] CHANGE [i:91ea6831b6]existing_field_name[/i:91ea6831b6] [b:91ea6831b6]new_field_name[/b:91ea6831b6] INT(11);[/quote:91ea6831b6]........
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    Create Table with structure of another existing tableOk, this has many valid uses such as if you need to create backups or the ability to undo changes, you would want to create new tables with the same structure as another. Here is how you do it. [i:7ed9581493] Also remember Indexes such as PRIMARY KEYS [b:7ed9581493]will not be preserved[/b:7ed9581493] so you will have to readd them manually.[/i:7ed9581493] [code:1:7ed9581493]CREATE TABLE NewName AS SEL........
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    ADD PRIMARY KEY to TableHere is an example of readding a PRIMARY KEY with an AUTO_INCREMENT field: [b:40986c2a8b]First make the field NOT NULL[/b:40986c2a8b] [code:1:40986c2a8b] ALTER TABLE tableName MODIFY FieldNAME INT(18) NOT NULL; [/code:1:40986c2a8b] [b:40986c2a8b]Create The Primary Key[/b:40986c2a8b] [code:1:40986c2a8b]ALTER TABLE tableName ADD CONSTRAINT PRIMARY KEY(FieldName);[/code:1:40986c2a8b........
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    Linux Security Mini-tutorialThis site has a good tutorial to get you started on securing your Linux system. Although I'm sure all of our systems are already 100% secure :lol: http://www.yolinux.com/TUTORIALS/LinuxTutorialInternetSecurity.html........
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