Archive

Archive for the ‘sysadmin’ Category

copy your debian installed packages to a new machine

June 17, 2017 Comments off

Run this to retrieve a list of installed packages:

dpkg -l | grep ^ii | awk ‘{print $2}’ > installed_packages

Then install on new system with:

apt-get install $(cat installed_packages)

You should probably look at installed_packages and remove any obvious
errors.

Categories: sysadmin

Turn on syntax (color) in vim for Debian

February 8, 2017 Comments off

To add syntax checking to vim with Debian, just edit /etc/vim/vimrc and uncomment
the “syntax on” line.

Then your editor will show (in color) syntax errors in Postfix and html/css files.

Categories: sysadmin

disable or enable ipv6 ssh

September 20, 2016 Comments off

You may experience problems with ssh and ipv6. If so edit the /etc/ssh/sshd_config file
and enable the ListenAddress 0.0.0.0 option. You can also enable (unpound) the ipv6
option ListenAddress ::.

You may experience lockouts from ssh if you have AAAA ipv6 records in your nameserver if
you don’t make theses changes.

Be sure and restart ssh after changes.

Categories: sysadmin

Check Spamassassin perl modules

June 19, 2016 Comments off

To check spamassassin and verify all required perl modules are installed
run this:

spamassassin -D –lint 2>&1 | grep -i failed

then use cpan install module::name ie
cpan install Digest::SHA1

Some additions are required to augment the default install. There is benefit
to adding missing modules as a more complete spam analysis will occur.

Categories: sysadmin

Backup/Copy mysql or mariadb database

March 19, 2016 Leave a comment

You can copy or backup all your databases with these commands including
coping to another server.

# backup
mysqldump -u root -p yourdb > mysqlbak.sql
or for dumping all databases
mysqldump –all-databases -u root -p > mysqlbakall.sql
# restore
mysql -u root -p yourdb < mysqlbak.sql
to restore all databases
mysql -u root -p < mysqlbakall.sql

Categories: sysadmin

Cloning mikrotik routerboard (rb7xx, rb9xx, rb11xxx)

February 1, 2016 Leave a comment

You can easily clone like routerboard hardware with these commands:

First to ssh admin@youripaddress or run terminal from winbox and run the following on the device you want to clone in this example we clone an rb751g to rb951.

## on rb751g type:
/export compact file=name

Then copy the name.rsc file to the rb951 $$either drag and drop it to files with winbox or use sftp.

hard reset the device you want to clone to by powering off and holding reset button, powering on,
and releasing reset button when led next to power plug starts to rapidly flash. Wait until the
os initializes and access with winbox.

## on rb951 type (after hard reset):
/import name.rsc ## you should see no errors.

## then on rb951 type:
/system reset run-after-reset=”name.rsc”
This will clear the current config and import the one from the rb751g

After a minute to load or so you should be able to access the rb951 with winbox and have a complete clone
of the rb751g.

Categories: sysadmin

Install libguestfs-tools and add serial console access to your vm

November 13, 2015 Leave a comment

To add serial access to your vm, with Debian/Ubuntu apt-get install libguestfs-tools.
Then with vm shutdown, execute the following:

root:~# guestmount -d vmname -i /mnt
root:~# ln -s /mnt/lib/systemd/system/getty@.service /mnt/etc/systemd/system
/getty.target.wants/getty@ttyS0.service
root:~# umount /mnt

Reboot your vm and you should have serial console access.

Categories: sysadmin