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.........
In newer of versions of Virtualbox, especially above 6.0 (eg. 6.1 like the example below), a lot of times the "Enable Nested VT-x/AMD-V".
If you are having this issue, you will see the option is grayed out. It doesn't mean that your computer does not support virtualization, although it is possible it is disabled in the BIOS. You can verify........
Just a quick note and warning is that if you are testing to see if EFIPXE booting works on a VM, MAKE SURE it actually works. For example Iinitially tested using my Distro's QEMU 2.5+dfsg-5ubuntu10.46 and ovmf BIOS firmware (OVMF supports EFI). However, I found on old versions of QEMU (like 2.5), EFIbooting with GRUB NEVER works so it may appear that you have made a mistake when everything is fine when you boot a physi........
It really seems limited in that it can mainly give you the things you would see on the physical unit such as load etc..
tar -zxvf apcupsd-3.14.14.tar.gz
apt install software-properties-common
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........
A big problem over ssh and especially sshfs is that your connection will often timeout and disconnect after inactivity.
To fix this you can modify the server but it may not be practical or you may not have access. Why not send keep alives fom your end (client side)?
Just edit /etc/ssh/ssh_config (not to be confused with sshd_config as that is the server side):
Find the line that says "Host *" and change it like this:........
The cool thing here is that we only need 1 drive to make a RAID 10 or RAID 1 array, we just tell the Linux mdadm utility that the other drive is "missing" and we can then add our original drive to the array after booting into our new RAID array.
Step#1 Install tools we need
yum -y install mdadm rsync
Step #2 Create your partitions on the drive that will be our RAID array
Here I assume it is /dev........
Most of us know the heredoc method but what if you need a basic query done repeatedly and manually while working from bash? It is a pain to manually type mysql and login each time.
With this command below you can semi-automate those queries:
echo "use somedb; select * from auctions" | mysql -u root --password="yourpassword"
Just modify the above to suit your needs and you can add more queries by adding a sem........
create database yourdbname;
Show All Databases:
Drop / Delete a MySQL Database:
drop database nameofyourdatabase;........
chroot which stands for change root allows you to virtually operate in another operating system even though you haven't booted it. It is commonly used to deploy new distros, applications and to fix a broken Linux/Unix install or prep a new system image without having to physically boot the drive or disk.
So in this example let's say we have a drive that has a Linux OS installed on /dev/sdb1 and we have mounted this partition on /mnt/sdb1
The key point is to edit the &quo........
The key thing is that you must use a "machine"id of "pc-1.3" or it will say your hardware is not supported.
Additionally you MUST use a virtio disk or you will get a ks_pre.sh error as soon as the install starts (a look at logs will show it can't find a disk). This is funny because even though the OS finds the disk and an fdisk -l shows it, it looks like the script looks for a /dev/vda device (virtio) and nothing else, so if you didn't use Virtio as you........
The key thing here is to know the actual partition that is encrypted.
Often in Linux Mint's installer that ends up being partition 5 or /dev/sda5
sudo cryptsetup luksOpen /dev/sda5 anynamehere
You will then be prompted for your irrecoverable passphrase:
Enter passphrase for /dev/sda5:
If all goes well it won't say anything further. If it says ""No key available with this passphr........
lvreduce -L -100G /dev/mapper/centos-home
Do you really want to reduce centos/home? [y/n]: y
Size of logical volume centos/home changed from ........
Ihave 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 Idid:
[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........
So I have a domain "testdomain.com".
Inside test domain.com's root is the following .htaccess:
Options +FollowSymLinks -Indexes
ErrorDocument 403 /launch/index.html
Deny From All
Allow From 192.168.1.2
When you visit anything other than root things work fine. Eg. if you visit http://testdomain.com/somedirfile.html
It will show the right error in /launch/........
I modified this code after quickly learning how Wordpress plugins actually work, how they're called etc.. was the first trick to modifying the code to add tags.
Add this code after line 570 in wp-content/plugins/wp-instagram-post/classes/class-woo-igp.php
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........
M4A is a weird format, so you have to be creative here is a quick copy of what I did.
Basically you need to convert to .wav to make use of them and thenI converted the resulting .wav into an mp3 (nice small file size and basically universally playable):
sudo apt-get install mpg321 mp3gain faad normalize lame
faad "Voice 002 (copy).m4a"
faad "Voice 002 (copy).m4a"........
VBoxManage modifyhd "my.vdi" --resize 60000
Note the above will resize my.vdi to 60,000MB........
For themes and custom CMS setups, the typical HTML theme is not ready to go at all but here are some common sed commands (search and replace that will get most of them working without breaking as you'd expect).
The problem is that often the theme directory will be separate from the content and this will break the relative paths that these themes use.
sed -i s/'href="'/'href="/themes/yourtheme/'/g index.html
sed -i s/'src="'/'src="/themes/y........
Many may ask why would you need to do this? When upgrading from phpBB 2 to 3 the conversion does not keep the admin user you create. If your old admin user has an email address associated that no longer works or is accessible this makes it impossible to reset the admin password.
Some may just say "I'll just manually edit the e-mail address" but it won't work and phpBB will fail to find that user if you don't update the "user_email_hash" field but how do........
Usually just modify the .spec file to resolve this:
Change "Copyright: GPL" to "License: GPL" and try again.........
I never found a solution to do it live (nothing worked that I found) so it looks like a relogin is required.
Check your maximum file limit
This is different than your actual's user limit which you'll see below
Try and set it higher but it won't work
ulimit -n 65000........
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.........
Step #1 - Create Wrapper Script
VBoxManage modifyhd XP.vdi --resize 15000
VBoxManage modifyhd XP.vdi --resize 15000
That resizes the virtual hard drive image "XP.vdi" to 15000MB instantly.
I doubt this is safe to do while the VM is running and I'm not sure if it would attempt it still but turn the VM off first to be safe.
I also notice in the VBOX GUI that it still shows the orig........
VBoxManage modifyvdi /path/to/your.vdi compact
I believe this should be done only when your VM is powered off, but I decided to try it with the system powered on. i wouldn't recommend it because it's dangerous even if it does work but this is a test system. For anything important/production I would always take a backup first and make sure the system is powered off.
VBoxManage modifyvdi XP-clone.vdi compact
I am a huge fan of Linux and the idea of OpenSource but I've said it many times, there are still hurdles in today in 2010 for Linux as a Desktop. Linux is still intended for servers at its very core. This can be changed succesfully though, as Apple has shown us with Mac OS X based on FreeBSD.
Half of the issue is lack of driver support and the other half is the Linux Kernel and Window Manages, KDE and GNome still both don't cut it (but they're getting closer).
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.
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........
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]
ALTER TABLE tableName MODIFY FieldNAME INT(18) NOT NULL;
[b:40986c2a8b]Create The Primary Key[/b:40986c2a8b]
[code:1:40986c2a8b]ALTER TABLE tableName ADD CONSTRAINT PRIMARY KEY(FieldName);[/code:1:40986c2a8b........
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........