• 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........
  • 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........
  • 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........
  • tar do not overwrite files


    It is as simple as using the "-k" option for: -k, --keep-old-files don't replace existing files when extracting --keep-newer-files don't replace existing files that are newer than thei........
  • MySQL how to copy/duplicate a table


    CREATE TABLE articles_backup LIKE articles The code above creates a new table called "articles_backup" which has the exact same structure and attributes as the original articles table. CREATE TABLE articles_backup SELECT * FROM articles; The above code does the same thing as the first example, BUT it also copies all of the data.........
  • VirtualBox Convert Import/Boot .vmdk VMWare Hard Disk/Drive Image Won't Work


    I wanted to Import/Use a .vmdk hard disk image file from VMWare. Generally you can just "point" VirtualBox to it and use it and it will work but I found an exception. One of my Centos 4.4 x64 images wouldn't boot. I had two copies, an older one and the newer one. The older one booted as normal (once I changed the VirtualBox driver to IDE from SATA). The newer one stopped at the "GRUB loading" message no matter what I tried. As far as........
  • tar gzip: stdout: File too large - Error Size Limit on Large file > 17GB


    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 "........
  • How To Save iptables firewall rules Centos/Redhat/Fedora Linux


    This is something that annoys a lot of people, fortunately the Redhat style OS's are the most simple in this respect. I disagree that Debian's way makes sense, it is more of a hackish approach in how they implement iptables. Anyway, for those who are using Redhat/Centos style OS's it is very simple. Set your rules from the shell/command prompt and to save the iptables firewall rules so they are remember/loaded on boot just run this command: service iptables........
  • Latest Articles

  • ImageMagick Convert PDF Not Authorized
  • ImageMagick Converted PDF to JPEG some files have a black background solution
  • Linux Mint Mate Customize the Lock screen messages and hide username and real name
  • Ubuntu/Gnome/Mint/Centos How To Take a partial screenshot
  • ssh how to verify your host key / avoid MIM attacks
  • Cisco IP Phone CP-8845 8800/8900 Series How To Reset To Factory Settings Instructions
  • ls how to list ONLY directories
  • How to encrypt your SSH private key file id_rsa
  • Linux Mint 18 Disable User Name List from showing on Login Screen
  • Firefox Cannot Hit Enter Key In Address Bar and Location History Not Working
  • Cisco Unified Communications Manager / CUCM IP 8.6,10,12 Install Error Solution
  • Ubuntu Debian Mint Linux SSHD OpenSSH Server Not Starting After Reboot Solution
  • nmap how to scan for all ports and not just the 1000 most common ports
  • Windows 7,8,10 and Server 2008, 2012, 2016, 2019 Read Only Attribute Won't Go Away
  • bind / named how to make a wildcard record and retain defined A records
  • Cisco Unified Communications Manager 12 Install Errors on Proxmox/KVM
  • Local Vs Universally Administered MAC Address NIC Refuses to come up
  • Cisco Unified Communications Manager 12 CUCM 12 - How To Enable Video Calling
  • Windows 7, 8, 10, Windows Server 2008, 2012, 2016, 2019 How To AC97 Audio Drivers and Other Unsigned Drivers
  • Cisco Unified Communications Manager / CUCM IP Telephony Definitions