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........

Traditionally kernels were numbered starting from 0 but by default the "new style" of grub boot loading considers each subkernel item to be different so if you have 3 entries for 4.40-148 rather than counting for 1. To get the expected behavior let's show this example and how we can boot it We do a grep on menuentry in /boot/grub/grub.cfg to see all of the bootable kernels rather than scrolling through loads of extra entries we don't care about (thou........

4.374647] usb_common: exports duplicate symbol usb_get_dr_mode (owned by kernel) [ 4.403334] usbcore: exports duplicate symbol __usb_get_extra_descriptor (owned by kernel) [ 4.427736] xhci_hcd 0000:00:15.0: xHCI Host Controller [ 4.427844] xhci_hcd 0000:00:15.0: new USB bus registered, assigned bus number 1 [ 4.429040] xhci_hcd 0000:00:15.0: hcc params 0x200077c1 hci version 0x100 quirks 0x01109810 [ 4.429141] xhci_hcd 0000:00:15.0: cache line size of 64 is not sup........

INFO [07-19|12:11:51] Imported new block receipts count=590 elapsed=8.440s bytes=74117699 number=4870906 hash=6bc60b…934753 ignored=0 INFO [07-19|12:11:57] Imported new state entries count=499 elapsed=9.963ms processed=71076 pending=1526 retry=2&nbs........

This usually happens when you are using something like an INT and try to insert a larger valuethan the maximum which is larger than "2147483647" On a practical term I have seen this and been guilty of this error when using scripts like PHPand generating large random numbers: $hash = mt_rand(5,9999999999999); Obviously that many 9's are more digits than the maximum of an INT resulting in that error. Change your code accord........

MySQL will silently truncate a larger INT than capable. Check MySQL's own documentation here: As we can see the maximum size of INT (which is the most commonly used) is 2147483647 A lot of coders make this mistake by using very large values such as 9999999999 but it would actually truncate to 2147483647 which is the maximum size of an INT. This is dangerous beca........

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. ........

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 -........

Solution: yum -y install --skip-broken package-you-want-to-install Packages skipped because of dependency problems: php56w-mysql-5.6.30-1.w6.x86_64 from webtatic Error: Multilib version problems found. This often means that the root cause is something else and multilib version checking is just pointing out that there is........

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

There are a few ways of doing this and all basically involve using the reverse proxy or "ProxyPass" feature of Apache to accomplish it. 1.) Create a normal vhost and simply symlink the root directory of the site you want to mirror. Eg. originalsite.com and newsite.com /vhosts/originalsite.com/httpdocs You would symlink like this: ln -s /vhosts/originalsite.com/httpdocs vhosts/originalsite.com/........

Device Boot Start End Blocks Id System /dev/sdc1 1 132 1060256+ fd Linux raid autodetect Partition 1 does not end on cylinder boundary. Partition 1 does not start........

This command in Debian/Ubuntu/Mint will get everything need installed for most Java based KVM viewers: sudo apt install icedtea-netx The following additional packages will be installed: ca-certificates-java icedtea-netx-common openjdk-8-jre openjdk-8-jre-headless It seems every other updated version of Java or Icedtea breaks things and I will save the frustration of Java for another post.........

If a service is not working and resetting it to defaults is not working and you get bizarre error messages it is probably a broken update and possibly duplicate package. Take in this case "exim" not working even after resetting to defaults. Check for duplicates: rpm -aq|grep exim ........

This can happen when you install RPMForge or other repos with the wrong architecture and here's how you fix it (simply uninstalling won't usually fix it): solution yum clean all yum -y install openvpn Loaded plugins: fastestmirror, presto Loading mirror speeds from cached hostfile * base: mirror.its.sfu.ca * extras: centos.mirror.nexicom.net * rpmforge: mirror.cpsc.ucalgary.ca * up........

This is a great way to test and experiment without risking your current table, or to make a backup of your current table to avoid corruption or dataloss due to malicious activity eg. deletion etc.. There are two steps and two commands 1.)Copy Table Structure "cars_backup" is the new table and it will be a copy of the table called "cars"........

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.........

Have you ever found a website/page that has several or perhaps dozens, hundreds or thousands of files that you need downloaded but don't have the time to manually do it? wget's recursive function called with -r does that, but also with some quirks to be warned about. If you're doing it from a standard web based directory structure, you will notice there is still a link to .. and wget will follow that. Eg. let's say you have files in http://serverip/documen........

Error Detected........

For many reasons you may be dealing with a standard text file and you want to know if there are any duplicate lines: Here's how you do it: cat filename|uniq -c The "uniq -c" program counts how many time each line occurs.........

This is a great way to reduce MySQL code/mistakes/annoyance when doing things, take for example this statement: INSERT IGNORE INTO sometable(CatName) VALUES("someitem"); Notice the "IGNORE", that is what does the magic. Normally if the entry "someitem" existed you'd get an error message back such as "Duplicate entry for whatever". What I have normally done in PHP or whatever language is manually coded or made a........

I decided on using yum to help me decide even though I normaly use proftpd I decided to see what else I could find. yum search ftp Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * rpmforge: ftp-stud.fht-esslingen.de * base: mirrors.netdna.com * updates: updates.interworx.info * addons: yum.singlehop.com * extras: mirrors.netdna.com rpmforge........

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