Never the Lost

Old School .bashrc setup

Loren — Mon, 21 Nov 2011 23:58:54 +0000

#
# Bash Time stamps
#
HISTTIMEFORMAT=”[%c] ”
export HISTTIMEFORMAT

#
# Personal Aliases
#
alias ssr=’ssh -l root’
PS1=”\n<\[\033[0;32m\]\h\[\033[0m\]> \w (\[\033[0;36m\]\u\[\033[0m\])$ “

Quick and Easy Perl ipaliases setup

Loren — Thu, 14 Jul 2011 03:21:17 +0000

So lets start by defining what ip aliases are. I put these in the same category as virtual interfaces. In other words these are not physically connected interfaces but are stacked on top of the main interface, in most cases this is eth0.

First lets take a look at the actual perl script. In this case I called it ipaliases.pl and I chmoded it to +x. I also stored this script in /etc/global/ (my nice default for custom scripts on my boxes). The script is rather simple in the fact that it opens /etc/ipaliases for reading as the variable ipaliases. We then do a while loop on the file and use the system command to output the exact text line by line thats listed in that file.


##
#/bin/perl
#
# network       Perl script to quickly bring up IP aliase interfaces
#
##

open(ipaliases, "/etc/ipaliases");

while() {

system($_);

}

Next is our /etc/ipaliases file which looks like below:


ifconfig eth0:2 192.168.1.102 netmask 255.255.255.0 broadcast 192.168.1.255
ifconfig eth0:3 92.168.1.102 netmask 255.255.255.0 broadcast 192.168.1.255
ifconfig eth0:5 12.68.12.98 netmask 255.255.255.0 broadcast 192.168.1.255

As you can see this is what a hand upping of an interface looks like. And lastly I added this line to the /etc/rc.local on a independent line:


perl /etc/global/ipaliases.pl

So now on reboot those will be automatically added back in to the system.

Remote System Logging with Syslogd

Loren — Thu, 26 May 2011 21:35:35 +0000

With the need to back fill my time some days I have been looking into and trying to get a centralized syslog server deployed for a while. This is a huge benefit for the fact that as it says it is centralized. So I have finally had enough time to be able to tackle this as of today and wanted to write down some of my notes to keep it fresh and to also let people be able to find it. The big thing is that default after installation of a CentOS host you could set this up in a few minutes.

Lets start on the host in which we want all the logs to be pushed to.

vim /etc/sysconfig/syslog
Where you see the option of SYSLOGD_OPTIONS= add -r in the quotes. So it should look something like SYSLOGD_OPTIONS=”-r -m 0″
:wq

Next you need to edit the actual syslog conf file:
vim /etc/syslog.conf
now add in the following or something similar in this case I did cisco switches

local1.*   /var/log/cisco.log
local2.*   /var/log/cisco.log
local3.*   /var/log/cisco.log

:wq

Now restart the syslog service:
/etc/init.d/syslog restart

You should now notice at this point that /var/log has a file that was created called cisco.log. This is where all the information will be written to.

Now lets go ahead and setup a cisco host to log to this server:

conf t

logging event link-status global
logging event trunk-status global
ntp logging
ntp server
logging facility local1 (you would use which ever one you wanted to allocate)
logging
logging trap 7

exit
wr mem

Now all your logs should funnel into your log server.

nginx major fail as it just didn’t work for my application

Loren — Thu, 14 May 2009 14:07:11 +0000

So if you have ready any of my previous postings you will see that I setup nginx as a reverse proxy to help speed things up on my personal VPS. This seemed to work wonders and dramatically reduced the load on my VPS. Well I have updates

After agreeing to host a friends projects and one of his friends projects I ended up having to scrap nginx. It wasn’t that I didn’t think it was cool but it actually added extra load to my server for some reason. Let me explain, my f riend runs some pretty neat sites that get a lot of traffic. Some of them include www.mycodeteacher.com www.iphonedevcentral.org and www.topvoicesnow.com. All of these sites either have streaming video or streaming media in general. nginx just didn’t give me what I was looking for as it was causing issues on the sites and jacking my load up to the point it would crash the web server.

The World of RAID

Loren — Sun, 10 May 2009 02:05:37 +0000

In the world of servers there are many options when it comes to protecting your disks and the data on those disks. You can create backups of your disks or even get creative and rsync your data to another drive or to an off site storage area. On my server I chose to go with a RAID array.

In my line of work I see a number of times that people over look their data. They then have a drive failure or some other catastrophe and then poof their data is gone. Their first feeling of emotion is to blame their host or to some other extent any one besides them selves. This is often the “fear” that is talking but in some cases they just could not afford it.

I’m not saying I’m rich and by far I do see the requirement for data security. I have been stupid before in my choices but this time around I wanted to make sure I protected my servers most important data from failure. Of course a $400 RAID card would have been great but I couldn’t afford that at the time I started to use this server. So I went with something a little bit different called a software RAID.

Redundant Array of Independent Disks is what RAID stands for, it has been revised from the “Inexpensive” disk version originally created. As I only chose to go with RAID-1 as I have a server with 4 disks in it. I got thinking that I wanted to test how well a software raid worked. So like any confidant geek I went to the data center and pulled on of the drives in the array. My plan was to make sure my monitoring worked (it didn’t) and to make sure that everything kept running. So upon pulling it the server went on without skipping a beat. The bad thing was that it required to be looked at because I never got a failed RAID notice.

I checked using the “cat /proc/mdstat” command to get my array status:
Personalities : [raid1]
md0 : active raid1 sdb1[0]
488383936 blocks [2/1] [U_]
unused devices:

As you can see it only lists 1 drive out of two so we can see that something has gone wrong! I did some checking and noticed that all four drives were in fact being seen by my server so I did a reboot (I don’t know why I thought maybe the array would rebuild on its own.) of course I needed to interact with it (this is where a $400 + card comes in very nicely).

I checked my disks “fdisk -l”:
Disk /dev/sda: 160.0 GB, 160000000000 bytes (Primary OS Drive)
Disk /dev/sdb: 500.1 GB, 500107862016 bytes (RAID-1 Disk #1)
Disk /dev/sdc: 500.1 GB, 500107862016 bytes (RAID-1 Disk #2)
Disk /dev/sdd: 500.1 GB, 500107862016 bytes (Backup Drive)
Disk /dev/md0: 500.1 GB, 500105150464 bytes (RAID-1 Array)
Disk /dev/md0 doesn’t contain a valid partition table (Normal for the Way I did the Array)

So I added my disk back into the array and let it try to start rebuilding “mdadm /dev/md0 -a /dev/sdc1″

Now I check to see the status of the array “cat /proc/mdstat”
Personalities : [raid1]
md0 : active raid1 sdc1[2] sdb1[0]
488383936 blocks [2/1] [U_]
[>....................] recovery = 4.0% (19803264/488383936) finish=169.7min speed=46010K/sec

What do you know it is recovering / rebuilding . You can see it is going at roughly 46Mb per second with an estimated completion time of 169 minutes or just under 3 hours. Not bad for some freeness is it?

Quick and Easy Clean up for cPanel Servers

Loren — Wed, 29 Apr 2009 14:25:13 +0000

So with Disk space being an issue I thought how can we clean up on a cPanel server. This script is not perfect but it does a good job of clearing about 1GB of disk space on average I have noticed.

So create a new bash script I like to use vim so I would do vim disk_cleanup.sh and paste the following in:

## Out Put for the boys and girls to See the before usage

df -h

## Yum works best when cleaned often I have noticed

yum clean all

## Remove all Compressed logs / remove any variations / incrementals

rm -f /var/log/*.gz

rm -f /var/log/*.?

## And I said clean up after home!

# Any Core files that may have been dumped as they take up a good 40 to 60Mb of Disk space.

rm -rf /home/core.*

# Get rid of Easy Apache

rm -rf /home/cpeasyapache

# Get rid of Old MySQL Install

rm -rf /home/MySQL-install

# Get rid of other BS

rm -f /home/latest

rm -rf /home/cprubygemsbuild

rm -rf /home/cprubybuild

rm -rf /home/cprestore

rm -rf /usr/local/cpanel/src/3rdparty/*

cd /tmp

for files in `ls`; do rm -f $files; done;

## See what kind of Kernels you may have that are old but first lets remove any kernel sources

rpm -qa kernel-source | xargs rpm -e

## Display new space prior to any kernels being removed.

df -h

## List out the installed kernels

rpm -qa | grep kernel

## Give current running kernel

uname -a | awk {‘print $3′}

## End

The Nginx Way, How to Install on a cPanel Server

Loren — Wed, 29 Apr 2009 10:47:48 +0000

Recently a co-worker mentioned that they tried out nginx and noticed that it was quite snappy. I didn’t know exactly how it worked but thought I would give it a try. As a result I had this site down for a number of days while I corrected the issues. In the end I did the following:

Download the following and save them to/usr/src

http://wget.neverthelost.net/nginx/mod_rpaf-0.6.tar.gz

http://wget.neverthelost.net/nginx/nginx-0.7.52.tar.gz

http://wget.neverthelost.net/nginx/pcre-7.9.tar.gz

Once Downloaded we need to go ahead and install some of the pre-required items before getting into the dirty configuration parts.

cd /usr/src

tar xvzf mod_rpaf-0.6.tar.gz
cd mod_rpaf-0.6
/usr/local/apache/bin/apxs -i -c -n mod_rpaf-2.0.so mod_rpaf-2.0.c

Hit Enter one more time

cd /usr/src

tar xvzf pcre-7.9.tar.gz

cd pcre-7.9

./configure

make

make install

Hit Enter one more time

cd /usr/src

tar xvzf nginx-0.7.52.tar.gz
cd nginx-0.7.52
./configure –with-http_ssl_module –with-http_realip_module –with-http_dav_module –with-http_flv_module –with-http_gzip_static_module
make
make install

Hit Enter one more time

Now we have all of our required items installed we can start our configuration.

Do it your self Security….

Loren — Mon, 30 Mar 2009 11:07:12 +0000

Well recently I have been very interested in some aspects with securty at work. I have been testing and reviewing some great DVR systems that run on linux. So I went ahead and added a VPS to my OpenVZ server and turned up and installed Zone Minder. So far I have not been able to get the two cameras hook up and allow Zone Minder to monitor for motion, yet I still find it amazing at the quality of these cheaper cameras. I have done security systems before and usually they require a box of 3 to 5 thousand dollars and 30+ man hours just to setup and test the cameras. From this point you would be required to then setup users, remote access, and train the end user all while this hardware you have it on is usually a single drive system and really does you no good other than to have a over view of what ever you want to watch.

So right now my server is setup as the following:

- Intel Pentium D 3.)GHz (dual core) CPU

- 8GB DDR2 ECC Memory

- 160GB Primary Drive

- RAID-1 500GB /vz Drive for all VPS hosts

- 500GB /backup Drive for backups

- Janky Hot Swap Case

So my research finds Zone Minder to be a little resource intensive but this server dosen’t do much so I press on and install it anyways. I followed the same instructions you can find at http://www.zoneminder.com/wiki/index.php/CentOS#Step_Five_-_Installing_ZoneMinder_1.23.3 Wiki for Great Justice!

First Post of luck… I hope

Loren — Fri, 27 Mar 2009 12:35:11 +0000

All I shall say is I think Virutozzo 4 should have kept the progress bar like in Virtuozzo 2.5 and 3.0.