• efibootmgr: option requires an argument -- 'd' efibootmgr version 15 grub-install.real: error: efibootmgr failed to register the boot entry: Operation not permitted.


    This sometimes happens when trying to install the EFIversion of grub to a device when you are booted into Legacy/MBR mode. It doesn't seem to occur on all machines, but some and seems somewhat BIOS dependent. grub-install --target=x86_64-efi /dev/sda Installing for x86_64-efi platform. grub-install.real: warning: Couldn't find physical volume `(null)'. Some modules may be missing from core image.. grub-install.real: warning: Couldn't find physica........
  • docker swarm silly issues


    The error below can be caused by a gateway that is unpingable: docker swarm join --token SWMTKN-1-1kogg8da68gtb1j7ezaddowyy9s0an5s9tue758o20k18liskw-5h3f61hrrmv3u6agshvbtcklf 172.16.1.80:2377 Error response from daemon: manager stopped: can't initialize raft node: rpc error: code = Unknown desc = could not connect to prospective new cluster member using its advertised address: rpc error: code = DeadlineExceeded desc = context deadline exceeded........
  • Save money on bandwidth by disabling reflective rpc queries in Linux CentOS RHEL Ubuntu Debian


    Even today we see a lot of servers that have different services and ports open for rpc and this creates not only potential inward vulnerabilities but perhaps more common, the abuse of your network resources in reflective rpc queries. To stop this problem, you should disable and remove all services relating to rpc or at least block all relevant ports for the service. Surprisingly, there are still some providers and OS installs in Linux that install these services and leave them........
  • How To Stop DNSMasq from listening on all IPs/Interfaces and allow only localhost


    Some people find it less than intuitive to do on DNSMasq and by default DNSMasq is available on 0.0.0.0 which could even be your LAN or Public IP. Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp ........
  • Docker Swarm vs Kubernetes Comparison Guide


    A lot of companies are unsure which solution to choose and many may not be aware of Docker Swarm as an alternative to Kubernetes. One thing that many Sysadmins find is that Docker Swarm is simply easier, quicker to setup and maintain by far than Kubernetes.........
  • Proxmox install issue cannot see the buttons or install wrong / bad resolution cannot see the entire screen problem solution


    If you are using a hypervisor to test Proxmox (eg. Vbox) then changing the video card/display adapter can fix it. For example VboxSVGA causes the issue but switching to VMSVGA fixes it. For example VboxSVGA causes the issue but switching to VMSVGA fixes it. ........
  • request_module: runaway loop modprobe binfmt-464c Kernel panic - not syncing: No init found Pid: 1, comm: swapper/0 Not tainted solution


    request_module: runaway loop modprobe binfmt-464c Kernel panic - not syncing: No init found Pid: 1, comm: swapper/0 Not tainted This is usually caused by a mismatch in architecture and happens frequently in development environments. Here is a example of what caused this issue: Your binaries are based on one architecture Your kernel was compiled with another architecture. Why does this happe........
  • How to install and configure haproxy on Linux Ubuntu Debian


    haproxy is one of the best known and widely used Open Source load balancers out there and a strong competitor to nginx. haproxy is used by many large sites per Wikipedia: HAProxy is used by a number of high-profile websites including GoDaddy, GitHub,........
  • Debian Ubuntu apt install stop daemon questions/accept the default action without prompting


    This can be a real pain when automating things and you do an apt install and some packages ask a lot of questions. Make sure you set this variable when running: DEBIAN_FRONTEND=noninteractive Remember as well that if chrooting you will want to run like this: DEBIAN_FRONTEND=noninteractive apt install -y yourpackagename ........
  • Enable Turbo Mode for CPU Ubuntu Linux Mint Debian Redhat


    Sometimes due to your BIOS/EFI you may find that you have chosen "Energy Efficient" for your CPU which may effectively disable turbo mode. This is because "Energy Efficient" will often restrict or throttle your CPU to the base speed. This can impact nearly any CPU such as Intel's, AMDs, Opteron, Xeon etc... This is of course frustrating, for example if you have a CPU that is 2.0GHz base speed but turbo to 2.5GHz, you will never hit more than 2GHz.........
  • Cisco UC CME How To Enable Licensed Features


    Router#show license Index 1 Feature: ipbasek9 Period left: Life time License Type: Permanent License State: Active, In Use License Count: Non-Counted Lic........
  • md mdadm array inactive how to start and activate the RAID array


    cat /proc/mdstat Personalities : [raid1] [raid10] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] md124 : inactive sdj1[0](S) 1048512 blocks Solution, we "run" the array sudo mdadm --manage /dev/md124 --run mdadm: started array /dev/md/0_0........
  • Loaded: masked (Reason: Unit hostapd.service is masked.) Solution in Linux Debian Mint Ubuntu


    If you are getting this error from systemctl "Loaded: masked (Reason: Unit hostapd.service is masked.)" we need to unmask the service. Solution systemctl unmask hostapd Removed /etc/systemd/system/hostapd.service. It's fixed root@routerOS:/var/log# systemctl start hostapd root@routerOS:/var/log# systemctl status hostapd ● hostapd.service - Access point and authentication server for Wi-Fi and Ethern........
  • LightDM Mint Ubuntu Debian won't start errors Nvidia Graphics


    This error implies that there may be an issue with Xorg or maybe your NVIDIA GPU cannot start or initialize: 35 laptop kernel: [ 2031.857704] nvidia: loading out-of-tree module taints kernel. 35 laptop kernel: [ 2031.857724] nvidia: module license 'NVIDIA' taints kernel. 35 laptop kernel: [ 2031.857725] Disabling lock debugging due to kernel taint 35 laptop kernel: [ 2031.873280] nvidia: module verification failed: signature a........
  • How To Do Linux Network Bonding Teaming in Mint Debian Ubuntu


    Bonding is an excellent way to get both increased redundancy and throughput. It is similar to the "Network Teaming" feature in Windows. There are a few different modes but we will use mode 6, I think it's the best of both worlds, as it is not just a failover, but it provides round robin, so you will get redundancy and load balancing. So if you have a 1G single port, you will have a combined throughput of 4G at this point. Just bear in mind that the true thr........
  • Docker Tutorial HowTo Install Docker, Use and Create Docker Container Images Clustering Swarm Mode Monitoring Service Hosting Provider


    The Best Docker Tutorial for Beginners We quickly explain the basic Docker concepts and show you how to do the most common tasks from starting your first container, to making custom images, a Docker Swarm Cluster Tutorial, docker compose and Docker buildfiles.........
  • HongKong VPS Server, Cloud, Dedicated Server, Co-Location, Datacenter The Best Guide on Hong Kong, China Internet IT/Computing


    In our 2024 VPS Server/Cloud Buyer's Guide, we place the location of your VPS/hosting/server as one of the priorities that is often overlooked. 2024 Update - Datacent........
  • Juniper JunOS Command Overview and Howtos Switch, Router, Firewall Tutorial Guide


    Enable "cli" mode equivalent in JunOS cli Configure Mode configure So rather than going to the console on a Cisco switch and typing "enable" and then "conf t", the equivalent in JunOS is "cli" and "configure". How Do You Apply Changes You've Made? You can make all kinds of changes to the switch, but remember they are not........
  • Scanner not working in Linux Ubuntu Fedora Mint Debian over the network? Use sane-airscan!


    I have a Canon MF642c and the scanner wouldn't work. I tried to use saned but it didn't work with the BJNPlike it did for some other Canon models. Introducing sane-airscan with packages for the most common distributions: https://software.opensuse.org/download.html?project=home%3Apzz&package=sane-airscan http........
  • How To Replace Audio Track of Video using ffmpeg


    A very common use case is that you don't want to waste time using a video editor that requires you to open it up and manually import the video clip and audio clip, then manually delete the old audio track and import the video and new audio. That's too much work and time since we don't want to go through the hassle. ffmpeg is our solution, all we have to do is specify 3 variables and we're done! -i Windows2019-Server-Noaudio.mp4 is our in........
  • apcupsd how to setup and monitor APC UPS units


    It really seems limited in that it can mainly give you the things you would see on the physical unit such as load etc.. wget https://downloads.sourceforge.net/project/apcupsd/apcupsd%20-%20Stable/3.14.14/apcupsd-3.14.14.tar.gz?r=https%3A%2F%2Fsourceforge.net%2Fprojects%2Fapcupsd%2Ffiles%2Flatest%2Fdownload&ts=1598115866 tar -zxvf apcupsd-3.14.14.tar.gz cd apcupsd-3.14.14 [root@somebox apcupsd-3.14.14]# ./conf........
  • mdadm how to stop a check


    Is a mdadm check on your trusty software RAID array happening at the worst time and slowing down your server or NAS? cat /proc/mdstat Personalities : [raid1] [raid10] md127 : active raid10 sdb4[0] sda4[1] 897500672 blocks super 1.2 2 near-copies [2/2] [UU] [==========>..........] check = 50.4% (452485504/897500672) finish=15500.3min speed=478K/sec ........
  • How To Get Started on Ubuntu with gpt-2 OpenAI Text Prediction


    apt install software-properties-common add-apt-repository ppa:deadsnakes/ppa apt update apt install python3-pip apt install python3.7 curl gnupg python3.7-dev git ln -s /usr/bin/python3.7 /usr/bin/python3 pip3 install numpy keras_preprocessing curl https://bazel.build/bazel-release.pub.gpg | sudo apt-key add - echo "deb [arch=amd64] http://storage.googleapis.com/bazel-apt stable jdk1.8" | sudo tee /etc/apt/sources.list.d/bazel........
  • How To Install OpenProject on Centos 7 Step-by-Step Guide


    There are a few caveats that may not be obvious to everyone so I am going to cover them here but keep this in mind before starting. Before starting install epel or you will be missing tesseract: yum -y install epel-release #1) When you specify your SSL certificate with a full path, it really needs to exist where you tell it to (including the default location of /etc/ssl/certs and /etc/ssl/c........
  • ssh Received disconnect from port 22:2: Too many authentication failures


    If you are getting this error it is usually caused by having more than 5 keys in your ".ssh" directory. It is a bit of a bug and this is how it manifests itself. You will find at this point that you are not given any chance to enter a password, or if you are using key based auth that the same thing happens. You'll also find that this is happening with ALLservers you try connecting to. The solution is to move away key pairs from .ssh so that there ar........
  • OpenVZ vs LXC DIR mode poor security in LXC


    It is unfortunate that LXC's dir mode is completely insecure and allows way too much information from the host to be seen. I wonder if there will eventually be a way to break into the host filesystem or other container's storage? OpenVZ better security: [root@ev ~]# cat /proc/mdstat cat: /proc/mdstat: No such file or directory /dev/simfs 843G 740G 61G........
  • how to use ifplugd in Linux to execute a command or script when a NIC cable is unplugged or plugged in


    It is fairly simple to use once you know how to use it. However, the tricky thing is that by default it doesn't seem to be active or listen on any interface on manually specified. How To Install ifplugd First we install ifplugd sudo apt install ifplugd Let's enable it on our desired device(s) vi /etc/default/ifplugd set this line as so:........
  • mpv / mplayer with Radeon / AMD GPU Video Card Driver enable VDPAU GPU Accelerated Video Decoding


    The easiest way to know if your videos are playing with GPU acceleration are to watch the process of xplayer, mpv or whatever you are playing. The CPU usage should be no more than 10% for that process/program if it is using acceleration. Let's manually play with vdpau to make sure it works before we make it permanent: First make sure you have libvdpau installed: sudo apt install vdpau-driver-all If yo........
  • Centos 7 Stopped and Disabled Firewalld and ports still blocked


    This is a gotcha but be aware sometimes iptables may be active and loaded by default. Also make sure you don't just disable firewalld but also stop it otherwise it will still block stuff: systemctl stop firewalld If the above is not the issue then it is possible iptables is running and blocking stuff too, so you'll need to stop iptables. So in addition to opening firewalld or disabling it, you would need to disable iptables........
  • Cisco Unified Communications Manager Express Cheatsheet CUCME CME Tutorial Guide


    Video Links: How To Setup 2 Phones on a Single CME Router and get the GUI going. How to use Dialpeers with CME with two routers How to implement call restrictions using COR / Class of Restriction Getting started, let's enable ephones and DNs we can add a phone with........
  • Linux Ubuntu Debian Missing privilege separation directory: /var/run/sshd


    service sshd status ● ssh.service - OpenBSD Secure Shell server Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled) Active: failed (Result: start-limit-hit) since Wed 2019-10-02 11:07:54 EDT; 36s ago Process: 476 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=255) Oct 02 11:07:54 box systemd[1]: Failed to start OpenBSD Secure Shell server. Oct 02 11:07:54 box sys........
  • Virtualbox vbox not starting


    If you've just installed VBox and it is not starting or working, the most common problem is usually that you don't have your kernel source installed, which means there is no kernel driver for vbox so it can't work. You may get an error that says "Kernel driver not installed" in your Virtualbox. So the first thing you should do is install your kernel source by running this: sudo apt-get install linux-headers-`uname -r`........
  • Ubuntu/Gnome/Mint/Centos How To Take a partial screenshot


    By default printscreen or alt print screen will get the whole desktop or the application in focus, respectively. But what if you want to select a portion of the screen? gnome-screenshot: ksnapshot compiz This is a nicely integrated solution sudo apt-get install compizconfig-s........
  • Cisco Unified Communications Manager / CUCM IP 8.6,10,12 Install Error Solution


    Install Errors on Version 12: This error happened on QEMU emulator version 2.11.1 pve-qemu-kvm_2.11.1-5 on Proxmox/Debian but installing on QEMU.12 on Centos 6 did not produce the error. *Update it is not related to the OS or QEMU version. This happened in Centos 6 too after a second install. What really causes this even though you successfully install........
  • Ubuntu Debian Mint Linux SSHD OpenSSH Server Not Starting After Reboot Solution


    If you get error messages like this it is usually because /var/run/sshd does not exist. root@userbox:/# service sshd status ● ssh.service - OpenBSD Secure Shell server Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enab Active: failed (Result: start-limit-hit) since Wed 2019-04-10 02:24:44 EDT; 1 Process: 511 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=255)........
  • Cisco Unified Communications Manager 12 Install Errors on Proxmox/KVM


    The strange thing is that usually the first install or two will work on any new machine but then it suddenly won't. I had this experience on QEMU 2.13 on a different machine. There is something finicky or buggy about the CUCM installer even when choosing the same virtual hardware specs. qemu-kvm command: /usr/libexec/qemu-kvm -version QEMU PC emulator version 0.12.1 (qemu-kvm-0.12.1.2-2.506.el6_10.1), Copyright (c) 2003-2008 Fabrice Bellard ........
  • Linux How To Disable SATA NCQ For Better Performance


    This is the closest way to disabling it without using the "libata.force=noncq" kernel boot option is to set the queue to a depth of 1 which doesn't actually disable it. Change the sdc below to match the device you want to disable NCQ for. [root@officebox ~]# echo "1" > /sys/block/sdc/device/queue_depth Errors that indicate you are having a performance issue are these in messages or dmesg relating to N........
  • the sign-in method you're trying to use isn't allowed. For more info, contact your network administrator - solution for active directory


    This is usually because the Group Policy forbids that user or group from logging in. run "gpmc" (not "gpedit.msc" as that is for local computer settings when you are not using Active Directory) or go to Administrative Tools and Group Policy Management. Edit the default domain policy like below........
  • How To Use Letsencrypt SSL/TLS Encryption to Create Certificates without installing on the target machine


    For some reason, perhaps you don't want to run a daemon or let Letsencrypt have access to your production server. There is a way to use it like a normal CSR/CA setup in manual mode. ./letsencrypt-auto certonly --manual -d realtechtalk.com - www.realtechtalk.com   Eventually you will get prompted to create a certain path and file with certain data: Create a file containing just this data: Casdfasfadsfsad........
  • Cisco Switch Setup Guide Command List


    Enter configuration console: enable configure terminal This is important because if your console doesn't look like below none of the commands will work! Switch(config)# Save and Apply Settings wr Show Switch Configuration: show run Show Port List/Sta........
  • Centos 7 Reallocate logical volume space to another


    Do you hate how Centos 7 defaults to allocating most of your valuable space to /home even though it is a production server? Here is a quick guide on how to take back that space live, while online (of course make sure you have backups just in case something goes wrong!): First we will reduce our home dir by 100G: lvreduce -L -100G /dev/mapper/centos-home WARNING: Reducing active and open logical volume to ........
  • mdadm force resync when resync=PENDING solution


    cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] md127 : active (auto-read-only) raid10 sdc1[0] sdb1[2] 1953382400 blocks super 1.2 512K chunks 2 far-copies [2/1] [U_] resync=PENDING bitmap: 15/15 pages [60KB], 65536KB chunk Solution force repai........
  • Linux wlan0 check all wireless clients


    iw dev wlan0 station dump This is very useful because it is helpful if you are running something like hostapd and need to see the signal strength and negotiated connection speed. Station ff:ff:ff:ff:ff:ff (on wlan0) inactive time: 16309 ms rx bytes: 25451 rx packets: 325 tx bytes: 44381 tx packets: 159 tx retries: 0 tx failed: 0 signal: -72 [-72] dBm signal avg: -72 [-72] dBm........
  • How Does Cisco CUCM (Cisco Unified Communication Manager) Work?


    Cisco's CUCM (Cisco Unified Communication Manager) is a system that combines voice, video, data and mobile products into a single unified management suite. At its core, the CUCMis like a "Super PBX" that controls the flow of all communications through an organization even single or multiple site deployments. Cisco's CUCMmakes communication more effective and simple through centralized management and unification of communications resources.........
  • What DNS Options Does Active Directory Offer in Windows Server 2008,2012,2016 ?


    What Is Active Directory? Active Directory is essentially an enhanced, centralized database with a set of objects that make user management, authorization, and data management simpler. Active Directory is synonymous with "Domain Controllers" where a single "domain" often consists of multiple sites and members of the domain. Multiple domains can also be joined to belong to a tree ( a collection of domains). And the highest layer is the forest whi........
  • 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 Ialways 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........
  • Proxmox understanding the directory structure and why an NFS datastore appears to be missing files/isos


    Proxmox at the root of your storage creates and "images"and "templates/iso" folder for VM images and iso's respectively. It ignores files in any other location.........
  • [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 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........
  • OpenVPN auth-user-pass-verify ENV script error


    Starting with newer versions of OpenVPN Ibelieve 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........
  • Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10) Dovecot Solution


    This happens because Dovecot limits the maximum IMAPconnections per IPto just 10. This may be fine for a single client side IPbut if an entire office or multiple users are behind one IPor 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........
  • pcimodules and lspci not working alternative solution


    pcimodules no longer works it produces nothing probably because the format of /sys/bus/pci is different. lspci -k doesn't work on older lspci versions. pciutils can be compiled but it won't work if you have an old system and compile on a newer glibc. iteriate through /sys/bus/pci/devices/*/modalias cat /sys/bus/pci/devices/*/modalias pci:v00008086d00001237sv00000000sd00000000bc06sc00i00 pci:v00008086d00007000sv0000000........
  • mdadm how to mount inactive array


    myguy@devbox:~$ sudo mdadm -As myguy@devbox:~$ cat /proc/mdstat |grep sdf md125 : inactive sdf3[2](S) sudo mdadm --manage /dev/md125 --run mdadm: started /dev/md125 ........
  • 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........
  • ecryptfs how to mount or recover from a backup


    The easiest way to recover or mount an off-line ecryptfs directory is the built-in command from ecryptfs sudo ecryptfs-recover-private It will find your wrapped passphrase and ask for your password and mount it in tmp. Much easier especially when your current active OS is using ecryptfs too. This a fantastic tool when going through old backups.........
  • 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 ........
  • cudaminer freezes Linux Mint taints kernel


    When running cudaminer once it tries to initialize the card the entire screen freezes. The computer itself is still running but the Xorg is done for, you cannot even switch to another console window and must reboot (even an mdm or Xorg restart does not help). At first cudaminer will give you these errors: stratrum_recv_line failed ...retry after 15 seconds GPU #0: Geforce 210 with compute ca........
  • 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........
  • What happens when you unplug 1 or more devices from an mdadm RAID array to simulate a failure in Linux Ubuntu/Centos/Debian?


    In short the two drives in the array were /dev/sdd and /dev/sde. The kernel sees they were unplugged and have gone down as you can see below. mdadm caught the first one being unplugged /dev/sde and disabled the missing drive. However when the final drive that was part of the array is unplugged it didn't notice at all. Instead it complains about an IO error later for drives that the kernel knows do not exist anymore. [45817.162728] ata4: exception........
  • mdadm and lvm how to completely disable and remove vg/pv/lv


    In short the solution is just to use vgremove for the actual /dev/mapper device: vgremove /dev/mapper/backups-backuplv box mnt # mdadm --manage /dev/md8 --stop mdadm: Cannot get exclusive access to /dev/md8:Perhaps a running process, mounted filesystem or active volume group? box mnt # lv lvchange lvconvert lvcreate l........
  • mdadm frozen and doesn't realize array is dead/missing failed due to unplugged drives


    This was a surprising bug but I unplugged all drives for an array md127. At first it was just 1 drive and mdadm seemed to notice this. I unplugged the second drive taking the array offline but mdadm did not realize it was offline and still showed a non-existent disk as being part of it. This created problems trying to unmount it or even to stop this array with mdadm freezing. As for how to fix it I can only think of making sure you are not in a mounted path of........
  • Unable to mount location Failed to retrieve share list from server: No such file or directory solution


    Cannot even "Browse Network" when clicking on "Windows Network" Unable to mount location Failed to retrieve share list from server: No such file or directory logs: [2017/02/14 00:16:44.271314, 0] ../source3/nmbd/nmbd.c:58(terminate) Got SIGTERM: going down... [2017/02/13 17:35:41.797944, 0] ../lib/util/become_daemon.c:124(daemon_ready) &........
  • mdadm how to make inactive array active


    This happens when you assemble array it doesn't mean it will be active for many reasons: md20 : inactive sdf1[2](S) 732442488 blocks super 1.2 Solution: sudo mdadm --manage /dev/md20 --run........
  • 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: [17925926.174581] block drbd0: drbd_sync_handshake: [17925926.174586] block drbd0: self 2AAE66AF9252D6DB:2815BF........
  • mysql_real_escape_string returns an empty string solution


    This is a common mistake but many people do not realize this function comes from mysql itself, so therefore you need an active mysql connection open. Usually the string will be empty and null when you call it from outside of the database connection portion of your code. eg. an example of the wrong way and creating a null/empty string $var = mysql_real_escape_string($myself) mysql_connect(); // returns n........
  • Cannot Read License File cPanel Solution


    This can happen because port 80 is not open, or your license has expired and/or your IP is out of date and also if the license server itself from cPanel is having issues. In most cases as long as you have a valid license the following command will solve it: /usr/local/cpanel/cpkeyclt Updating cPanel license...Done. Update succeeded. Building global cache for cpanel...Done Cannot........
  • Apache SSL Reverse Proxy Very Slow Solution


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