Chris Reeves' Blog | Page 4 of 26 | Just another IT Blog

VMware Creating RDMs from Locally Attached SATA Disks

Posted 24/11/2015 by Chris & filed under Virtualisation, VMware ESX.

I recently had to connect two 4TB sata disks to a server to provide some raw storage to the network. Going on past experiences I didn’t want to virtualise the disks but rather present them to the virtual machine guest as a raw device mapping (RDM).

You will need a separate datastore that is separate to the ones you are attaching. It will have to be VMFS5 to get around the 2TB limit with VMFS3.

Note: This is not supported by VMware to the best of my knowledge.

Procedure

Start a SSH session to the VMware ESX host (or if on the physical server, drop to console)
Run fdisk to see the disk layout.

fdisk –l

fdisk –l

You will need to find the vml identifier, you need to match that to the drive.

ls /dev/disks/ -l

1	ls /dev/disks/ -l

In my example, the two I am interested in are:

vml.01000000002020202020202020202020205a33303346325742535434303030

vml.01000000002020202020202020202020205a33303351523246535434303030

Now browse to the VMFS5 datastore you will be creating the RDM’s

cd /vmfs/volumes/datastorename

1	cd /vmfs/volumes/datastorename

Best practise would be to create a folder for the RDM’s to sit in

mkdir RDMs

1	mkdir RDMs

Create the RDM’s by running the vmkfstools command (use the vml. location that you found in previous steps)

vmkfstools -r /vmfs/devices/disks/vml.01000000002020202020202020202020205a33303346325742535434303030 4TB_Disk1_RDM.vmdk -a lsilogic
vmkfstools -r /vmfs/devices/disks/vml.01000000002020202020202020202020205a33303351523246535434303030 4TB_Disk2_RDM.vmdk -a lsilogic

1 2	vmkfstools -r /vmfs/devices/disks/vml.01000000002020202020202020202020205a33303346325742535434303030 4TB_Disk1_RDM.vmdk -a lsilogic vmkfstools -r /vmfs/devices/disks/vml.01000000002020202020202020202020205a33303351523246535434303030 4TB_Disk2_RDM.vmdk -a lsilogic

Verify you have the files created

ls –lash

ls –lash

Attach to virtual machine

Should you have any questions, comments or suggestions, please don’t hesitate to comment below. If you like what you have read, please share it on your favourite social media medium.

Limit SSH connections geographically

Posted 27/08/2015 by Chris & filed under Linux & Unix.

There is a real security risk to leaving your shell connection ports exposed to the internet especially if you don’t ever intend on connecting from Zimbabwe as well as other random countries.

This can limit brute force attack exposure and also save valuable resources and bandwidth by rejecting a packets before a tcp handshake.

Install GeoIP

You will need to implement a database that can be queried locally that stores IP ranges to countries.

apt-get install geoip-database geoip-bin

1	apt-get install geoip-database geoip-bin

Query GeoIP database

geoiplookup 8.8.8.8

1	geoiplookup 8.8.8.8

The script

mkdir /scripts
vi /scripts/sshfilter.sh

1 2	mkdir /scripts vi /scripts/sshfilter.sh

Past the following in:

#!/bin/bash
ALLOW_COUNTRIES=&quot;AU&quot;

if [ $# -ne 1 ];
then
echo &quot;Usage: `basename $0` &lt;ip&gt;&quot; 1&gt;&amp;2
exit 0
fi

COUNTRY=`/usr/bin/geoiplookup $1 | awk -F &quot;: &quot; '{ print $2 }' | awk -F &quot;,&quot; '{ print $1 }' | head -n 1`

[[ $COUNTRY = &quot;IP Address not found&quot; || $ALLOW_COUNTRIES =~ $COUNTRY ]] &amp;&amp;; RESPONSE=&quot;ALLOW&quot; || RESPONSE=&quot;DENY&quot;

if [ $RESPONSE = &quot;ALLOW&quot; ]
then
exit 0
else
logger &quot;$RESPONSE sshd connection from $1 ($COUNTRY)&quot;
exit 1
fi

#!/bin/bash

ALLOW_COUNTRIES="AU"

if [ $# -ne 1 ];

then

echo "Usage: `basename $0` <ip>" 1>&2

exit 0

COUNTRY=`/usr/bin/geoiplookup $1 | awk -F ": " '{ print $2 }' | awk -F "," '{ print $1 }' | head -n 1`

[[ $COUNTRY = "IP Address not found" || $ALLOW_COUNTRIES =~ $COUNTRY ]] &&; RESPONSE="ALLOW" || RESPONSE="DENY"

if [ $RESPONSE = "ALLOW" ]

then

exit 0

else

logger "$RESPONSE sshd connection from $1 ($COUNTRY)"

exit 1

Enable script

chmod +x /scripts/sshfilter.sh

1	chmod +x /scripts/sshfilter.sh

Lock down SSH

Setup a deny all for the ssh daemon

vi /etc/hosts.deny

1	vi /etc/hosts.deny

Add the following into the deny file

sshd: ALL

sshd: ALL

Enable the script in the allow ssh file

vi /etc/hosts.allow

1	vi /etc/hosts.allow

Add the following into the allow file

sshd: ALL: aclexec /scripts/sshfilter.sh &amp;a

1	sshd: ALL: aclexec /scripts/sshfilter.sh &a

Testing

Test the script by inputting the script name and then an IP afterwards

/scripts/sshfilter.sh 8.8.8.8

1	/scripts/sshfilter.sh 8.8.8.8

Should output something like the following:

Aug 25 15:23:21 server root: DENY sshd connection from 8.8.8.8 (US)

1	Aug 25 15:23:21 server root: DENY sshd connection from 8.8.8.8 (US)

Update GeoIP

There is only one constant with the world and that is change, IP addresses are no exception.

Create a new file called update_geo.sh in /scripts

vi /scripts/update_geo.sh

1	vi /scripts/update_geo.sh

Add the following into the file

#!bin/bash

cd /tmp
wget -q https://geolite.maxmind.com/download/geoip/database/GeoLiteCountry/GeoIP.dat.gz
if [ -f GeoIP.data.gz ]
then
gzip -d GeoIP.dat.gz
rm -f /usr/share/GeoIP/GeoIP.dat
mv -f GeoIP.dat /usr/share/GeoIP/GeoIP.dat
else
echo &quot;Cannot download the GeoIP database&quot;
fi

#!bin/bash

cd /tmp

wget -q https://geolite.maxmind.com/download/geoip/database/GeoLiteCountry/GeoIP.dat.gz

if [ -f GeoIP.data.gz ]

then

gzip -d GeoIP.dat.gz

rm -f /usr/share/GeoIP/GeoIP.dat

mv -f GeoIP.dat /usr/share/GeoIP/GeoIP.dat

else

echo "Cannot download the GeoIP database"

Change the script to execute

chmod +x /scripts/update_geo.sh

1	chmod +x /scripts/update_geo.sh

Edit the crontab

crontab -e

1	crontab -e

Paste the following at the bottom of the crontab

* * 20 * * /scripts/update_geo.sh

1	* * 20 * * /scripts/update_geo.sh

Adding Colour to Linux Bash Shell

Posted 01/11/2014 by Chris & filed under Linux & Unix.

If the standard black and grey makes you feel uninspired, you can change this by adding two lines to your .bashrc file in the users profile.

1. Edit the .bashrc file

vi ~\.bashrc

1	vi ~\.bashrc

2. Add the following lines

force_color_prompt=yes
PS1='${debian_chroot:+($debian_chroot)}\[&#92;&#48;33[01;32m\]\u@\h\[&#92;&#48;33[00m\]:\[&#92;&#48;33[01;34m\]\w\[&#92;&#48;33[00m\]\$ '

1 2	force_color_prompt=yes PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\[email protected]\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '

Should you have any questions, comments or suggestions, please don’t hesitate to comment below. If you like what you have read, please share it on your favourite social media medium.

Install MediaWiki on Apache with mySQL

Posted 29/10/2014 by Chris & filed under MediaWiki.

From MediaWiki site: MediaWiki is a free software open source wiki package written in PHP, originally for use on Wikipedia.

I decided to give MediaWiki a try as a scripts repository so I thought I’d write a quick guide of how to install it on a Linux/Apache/mySQL server.

Assumptions

A fully qualified domain name with a host record pointing to a internet facing server
A fully working Linux server (my example is a Debian server)
Apache installed on the Linux server and listening on port 80
A preconfigured vhost
PHP installed
mySQL server installed

Installation

1. Download the compressed installation file

wget http://releases.wikimedia.org/mediawiki/1.23/mediawiki-1.23.5.tar.gz

1	wget http://releases.wikimedia.org/mediawiki/1.23/mediawiki-1.23.5.tar.gz

2. Extract the compressed archive

tar xvzf mediawiki*.tar.gz

1	tar xvzf mediawiki*.tar.gz

3. Copy files from mediawiki-1.23.5 folder to the root folder

cd mediawiki-1.23.5
mv * ../
cd ..
rm -rf mediawiki-1.23.5
rm mediawiki-1.23.5.tar.gz

cd mediawiki-1.23.5

mv * ../

cd ..

rm -rf mediawiki-1.23.5

rm mediawiki-1.23.5.tar.gz

4. Create mySQL Database

CREATE DATABASE $databasename

1	CREATE DATABASE $databasename

5. Create mySQL Database user

CREATE USER '$databaseuser'@'localhost' IDENTIFIED BY '$databasepass';

1	CREATE USER '$databaseuser'@'localhost' IDENTIFIED BY '$databasepass';

6. Grant database permissions to database

GRANT ALL PRIVILEGES ON $databasename.* TO '$databaseuser'@'localhost' IDENTIFIED BY '$databasepass';

1	GRANT ALL PRIVILEGES ON $databasename.* TO '$databaseuser'@'localhost' IDENTIFIED BY '$databasepass';

7. Flush mySQL privileges

flush privileges;

1	flush privileges;

8. Log into the site eg:

http://wiki.example.com

Click on “Complete the installation”

9. Select the language

10. Click continue

11. Input all database information

12. Change settings to suit your database requirements

13. Input name of MediaWiki and desired credentials

14. Configure options for your MediaWiki

15. Install MediaWiki

16. Installation complete

17. Download and copy the LocalSettings.php file to the root of the MediaWiki installation

18. Browse to your MediaWiki installation and log in

Example: http://wiki.example.com

Should you have any questions, comments or suggestions, please don’t hesitate to comment below. If you like what you have read, please share it on your favourite social media medium.

Browse websites in a Linux terminal

Posted 14/10/2014 by Chris & filed under Linux & Unix.

I stumbled upon a package that allows the user to browse websites in a terminal, I thought I’d spin up a VM and try this for myself…

Installing W3M

This is very simple, requires one package (two if you want images displayed in Xterm)

apt-get install w3m w3m-img

1	apt-get install w3m w3m-img

Browsing

Now this isn’t going to look pretty as it’s in a terminal but it will work

w3m google.com

1	w3m google.com

Navigation

You can use the arrow keys to navigate to the section you want or use the mouse to click on the particular area.

shift+ b = Take you back a page

shift + u = Gives you a URL prompt

Shift + h = Help menu

Should you have any questions, comments or suggestions, please don’t hesitate to comment below. If you like what you have read, please share it on your favourite social media medium.

VMware Creating RDMs from Locally Attached SATA Disks

Limit SSH connections geographically

Install GeoIP

Query GeoIP database

The script

Enable script

Lock down SSH

Testing

Update GeoIP

Adding Colour to Linux Bash Shell

Install MediaWiki on Apache with mySQL

Assumptions

Installation

Browse websites in a Linux terminal

Installing W3M

Browsing

Navigation

Archives

Categories

Install GeoIP

Query GeoIP database

The script

Enable script

Lock down SSH

Testing

Update GeoIP

Assumptions

Installation

Installing W3M

Browsing

Navigation

Tags

Archives

Categories