I accidently deleted the /etc/libvirt/qemu/networks/default.xml. How to restore it? Thanks.
On some distros you can find the original master in /usr/share/libvirt/networks. Alternatively it is in GIT upsteam.
Once you have the file, simply run as root
# virsh net-define default.xml
# virsh net-start default
# virsh net-autostart default (if you want it to run on boot)
Related
I wanted to disable some options in the MySql server strict mode, but for some reason I'm not even able to find its configuration file (my.cnf)
Currently installed MySql:
Ver 14.14 Distrib 5.7.20, for macos10.12 (x86_64)
Output generated by
mysql --help
Default options are read from the following files in the given order:
/etc/my.cnf
/etc/mysql/my.cnf
/usr/local/mysql/etc/my.cnf
~/.my.cnf
But there is no such file as my.conf
I had done some research work on SO but none of the advises has worked for me.
What I'm supposed to do?
There are defaults built into MySQL. The configuration file(s), if any, override the defaults.
Note that the config files are not looked at except during startup. So, editing or creating such a file has no effect until you restart mysqld.
If you mess up the syntax, mysqld will not start. Then you need to find the error, either during startup, or in a log file. (Or you could ask here "what is my syntax error".)
As for the location, and name, of the config files that will be used:
$ mysql --help
gives you the list for mysql, but perhaps you need it for the server, so try
$ mysqld --help --verbose
gives you long output; maybe 50 lines from the top, you should see something like:
Usage: mysqld [OPTIONS]
Default options are read from the following files in the given order:
/etc/my.cnf /etc/mysql/my.cnf /usr/etc/my.cnf ~/.my.cnf
You asked about my.conf; was that a typo?
Regardless, If those files are missing, you can create them, make them readable by mysql, and put things into it preceded by [mysqld] so that the server will see them.
Personal override
Regardless of what is in the defaults and/or config files, you can add to the last file given. In the examples above that is 'hidden' .my.cnf in your home directory. All you need to do is create a few lines:
[mysql]
some_setting = somevalue
[client]
some_setting = somevalue
That helps for the "mysql" commandline tool and/or other clients (maybe).
But if you need to make changes to the server mysqld, it needs to be in one of the other files. Again, the minimum is something like
[mysqld]
some_setting = somevalue
Note the mysqld to refer to the server. And remember to restart the service.
Another note: If you see (in an existing config file), !includedir ..., then go to that directory to find any number of further files. You could add your own file, say z.cnf (so it would be picked last) with the two (or more) lines as indicated above.
If you have installed Mysql 8 or Above using the package installer from mysql website, then follow what i did
Create the config file in your home directory vim ~/.my.cnf
Do open System preferences in mac
Then Select the configuration file you created on the option.
The content in this website says.
I had the urgent need to configure some specific stuff in MySQL 5.7 on my developer machine, a MacBook Pro running Mac OS Sierra. Unfortunately, I did not find a my.cnf file that could be customized anywhere?
Internet research showed that MySQL Database Server on Mac OS runs without a my.cnf config file by default, simply started with default values.
Luckily, it is pretty simple to customize the MySQL Server installation by creating and editing a custom my.cnf file like this:
sudo cp /usr/local/mysql/support-files/my-default.cnf /etc/my.cnf
Then edit / customize the /etc/my.cnf file as required and restart your MySQL Server.
Or you can refer to this answer
You could try:
$ locate mysql | grep my.cnf
It should reveal the location(s) if it exists.
I already install ipfs via go ipfs. and I don't know why I encounter an error when I want to run "ipfs init " in my Terminal.
could anyone help me to figure out where is the problem?
here is an image of my Terminal:
The default IPFS repository path is ~/.ipfs.
Perhaps you can try to change your default path using:
export IPFS_PATH=/path/to/ipfsrepo
And then run:
ipfs init
Also, have you by any chance installed go-ipfs from snap?
In my case, I have faced this same problem. Because I also installed IPFS Desktop, it initialized some configurations. If you want a fresh start, you delete the initialized IPFS node:
> /Users/scbas/.ipfs
If you have not made any directory for IPFS, then using
ipfs init
will automatically generate a node in your base Users/Username directory.
If you want to change the directory, you can create one and then change the path using this command in the terminal according to the directory you created:
export IPFS_PATH=/Users/<your system username>/<the name of directory you created>
For example, I created an ipfs-repo folder for my IPFS node, so I have to run:
export IPFS_PATH=/Users/jonah/ipfs-repo
Steps To Replicate
On Windows 8.
In shell (with SSH connection active):
rhc snapshot save [appname]
Error
No system SSH available. Please use the --ssh option to specify the path to your SSH executable, or install SSH.
Suggested Solution
From this post:
Usage: rhc snapshot-save <application> [--filepath FILE] [--ssh path_to_ssh_executable]
Pass '--help' to see the full list of options
Question
The path to keys on PC is:
C:\Users\[name]\.ssh
How do I define this in the rhc snaphot command?
Solution
rhc snapshot save [appname] --filepath FILE --ssh "C:\Users\[name]\.ssh"
This will show the message:
Pulling down a snapshot of application '[appname]' to FILE ...
... then after a while
Pulling down a snapshot of application '[appname]' to FILE ... DONE
Update
That saved the backup in a file called "FILE" without an extension, so I'm guessing in the future I should define the filename as something like "my_app_backup.tar.gz" ie:
rhc snapshot save [appname] --filepath "my_app_backup.tar.gz" --ssh "C:\Users\[name]\.ssh"
It will save in the repo directory, so make sure you move it out of this directory before you git add, commit, push etc, otherwise you will upload your backup too.
What if there are more than one my.cnf files on my server?
Which configuration file will be looked by MySQL?
Assuming one runs mysql under linux, there the option-files will be read in that order:
the file specified by option --defaults-file=/PATH/TO/my.cnf while startup of mysqld
/etc/my.cnf
/etc/mysql/my.cnf
SYSCONFDIR/my.cnf (usually sysconfdir is /etc)
$MYSQL_HOME/my.cnf
the path set by --defaults-extra-file=/PATH/TO/my.cnf
~/my.cnf (your homedir, usually used for mysql-client configuration)
Also keep in mind that there are three options which change this behavior in MySQL:
-defaults-file=/PATH/TO/my.cnf - only read that option-file
-defaults-extra-file=/PATH/TO/myextra.cnf - read all global option-files, then this
-no-defaults - ignore every option-file and start with default
Please also refer to the docs on option-files: MySQL-Docs
The one specified on the command line that starts the mysqld process, or if no configuration file is specified, the default location. On Linux it is in /etc. I don't know where the Windows default is, but you can look in the documentation.
I use mercurial in my project, and every time I push new changesets to the server by ssh, it ask me for a password.
Then how to config the mercurial to push with out asking password?
I works on Ubuntu 9.10
On Linux and Mac, use ssh-agent.
Ensure you have an ssh keypair (see man ssh-keygen for details)
Copy your public key (from ~/.ssh/id_dsa.pub) to the remote machine, giving it a unique name (such as myhost_key.pub)
Log in to the remote machine normally and append the public key you just copied to the ~/.ssh/authorized_keys file
Run ssh-add on your local workstation to add your key to the keychain
You can now use any remote hg commands in this session without requiring authentication.
Assuming you're using Windows, have a read of my Mercurial/SSH guide. Down the bottom of the post you'll find info on how to use PuTTy to do this for you.
Edit: -- Here's the part of the post that I'm talking about (bear in mind you'll need to have pageant running with your key already loaded for this to work):
Client: Setting up Mercurial
If you haven't already, make sure you install Mercurial on the client machine using the default settings. Make sure you tell the installer to add the Mercurial path to the system PATH.
The last step of configuration for the client is to tell Mercurial to use the PuTTy tools when using SSH. Mercurial can be configured by a user-specific configuration file called .hgrc. On Windows it can also be called Mercurial.ini. The file is located in your home folder. If you don't know what your home folder is, simply open a command prompt and type echo %USERPROFILE% - this will tell you the path.
If you haven't set up your configuration yet, then chances are the configuration file doesn't exist. So you'll have to create it. Create a file call either .hgrc or Mercurial.ini in your home folder manually, and open it in a text editor. Here is what part of mine looks like:
[ui]
username = OJ Reeves
editor = vim
ssh = plink -ssh -i "C:/path/to/key/id_rsa.ppk" -C -agent
The last line is the key and this is what you need to make sure it set properly. We are telling Mercurial to use the plink program. This also comes with PuTTy and is a command-line version of what the PuTTY program itself does behind the scenes. We also add a few parameters:
-ssh : Indicates that we're using the SSH protocol.
-i "file.ppk" : Specifies the location of the private key file we want to use to log in to the remote server. Change this to point to your local putty-compatible ppk private key. Make sure you user forward-slashes for the path separators as well!
-C : This switch enables compression.
-agent : This tells plink to talk to the pageant utility to get the passphrase for the key instead of asking you for it interactively.
The client is now ready to rock!
Install PuTTY.
If you're on Windows, open projectdir/.hg/hgrc in your favorite text editor. Edit it to look like this:
[paths]
default = ssh://hg#bitbucket.org/name/project
[ui]
username = Your Name <your#email.com>
ssh = "C:\Program Files (x86)\PuTTY\plink.exe" -ssh -i "C:\path\to\your\private_key.ppk" -C -agent
If it's taking forever to push, the server might be trying to ask you a question (but it's not displayed).
Run this:
"C:\Program Files (x86)\PuTTY\plink.exe" -T hg#bitbucket.org -i "C:\Program Files (x86)\PuTTY\plink.exe" -ssh -i "C:\path\to\your\private_key.ppk"
Answer any questions, and then try pushing again.
If you're using Bitbucket, open your private key with puttygen, copy your public key out of the top textbox, and add it to your user account: https://bitbucket.org/account/user/USERNAME/ssh-keys/