SysAdmin: January 2014

Jan 31, 2014

How to install GlusterFS 3.4.x server and client on Debian Wheezy 7.3

1. Install glusterFS 3.4.x

Add the GPG key to apt
wget -O - http://download.gluster.org/pub/gluster/glusterfs/3.4/3.4.2/Debian/pubkey.gpg | apt-key add - Add the source and update package list
echo deb http://download.gluster.org/pub/gluster/glusterfs/3.4/3.4.2/Debian/apt wheezy main > /etc/apt/sources.list.d/gluster.list

apt-get update Install gluster server and client apt-get install glusterfs-server glusterfs-client Ref: http://download.gluster.org/pub/gluster/glusterfs/3.4/3.4.2/Debian/README

2. Dealing with mounting issue at boot time

With GlusterFS 3.4.2, we may get in trouble trying to mount the gluster volume via /etc/fstab
<server-ip>:/gluster_volume /var/mount glusterfs defaults,_netdev 0 0 This may not mount the volume as we expect in previous version of glusterFS. Therefore, we have to use a script to mount our glusterFS volume at boot time.

How to apply for an Individual Taxpayer ID Number (ITIN) when filing tax

If you do not yet have an ITIN, you can include the application in your tax filing. Follow these steps to apply for an ITIN and file your tax return:

1. Complete IRS Form W-7.
2. Complete your federal and state tax returns using the number 999-88-9999 in place of a Social Security Number.
3. Print the tax returns and cross off the 999-88-9999 from the SSN field. Do not attempt to e-file your return.
4. Write "Applying for ITIN; Application attached" next to the SSN field.
5. Mail the signed federal return, the completed Form W-7, and all documentation required by the Form W-7 Instructions to the address specified in the Form W-7 Instructions. (Alternatively, you may choose to take all this information in-person to a local IRS office for processing.)
6. If you need to file a state tax return: Mail the signed state return and a copy of Form W-7 to your state's regular filing address.

Source: Turbotax
The free e-file from TurboTax is easy to use with a nice design.

Jan 26, 2014

Install VMware Tools on Debian Wheezy 7.3

To install VMware Tools on Debian Wheezy 7.3 we have install gcc, make, and linux hearders packages first (can be installed from the DVD source)
apt-get install gcc make linux-header* linux-kbuild*
Mount the VMware Tools iso
mount /dev/cdrom /mnt
Extract the tool
cd /mnt
tar xvf VMware* -C /tmp
Install VMware Tools
cd /tmp/vmware-tools-distrib
./vmware-install.pl
Note: If we clone a VM on vSphere and see the VMware Tools status as Current (not running), then we need to rerun the VMware Tools config after cloning
/usr/bin/vmware-config-tools.pl
After that, check if we can see the IP of the VM.

Jan 24, 2014

Enable HAProxy logging on CentOS

By default, HAProxy will not log to files unless we make some modifications
1. Create rsyslog configuration file
nano /etc/rsyslog/haproxy.conf
Add these lines to the file
# Enable UDP port 514 to listen to incoming log messages from haproxy
$ModLoad imudp
$UDPServerRun 514
$template Haproxy,"%msg%\n"
local0.=info -/var/log/haproxy/haproxy.log;Haproxy
local0.notice -/var/log/haproxy/admin.log;Haproxy
# don't log anywhere else
local0.* ~
Restart rsyslog service
/etc/init.d/rsyslog restart
Ref: http://blog.hintcafe.com/post/33689067443/haproxy-logging-with-rsyslog-on-linux
2. Modify the log rotate config to match the new folder:
nano /etc/logrotate.d/haproxy
Change
/var/log/haproxy.log {
daily
rotate 10
missingok
[...]
to
/var/log/haproxy/*.log {
daily
rotate 10
missingok
[...]
Now we can check if HAProxy logging is working.
tail -f /var/log/haproxy/haproxy.log

Jan 18, 2014

How to get free credit score, report, and monitoring from 3 major bureaus Equifax, Experian, and TransUnion

If we live in the U.S. and do care about our credit history, score, and report (actually, we should), there are truly free ways to get free credit score, report, and monitoring from 3 major bureaus Equifax, Experian, and TransUnion. By truely I mean that these services require no credit cards, and some of them require us to enter only the last 4 digits of our social security number (SSN). Well, at least it is better than entering a full SSN.

1. Equifax https://www.quizzle.com
Quizzle now offers our full credit report, monitoring and credit score from Equifax and also a Vantagescore. Just go to https://www.quizzle.com/ and register an account.

2. Experian https://creditsesame.com
Credit seame offers our credit score and monitoring from Experian. However, it does not provide a full credit report, even though we can still see a list of all our credit cards.
Just go to https://creditsesame.com and register an account.

3. TransUnion https://www.creditkarma.com
Credit Karma offers our credit score and monitoring from TransUnion and an acceptable report that helps us understand our credit score, which I find it very useful to understand what is going on with my credit score. Credit Karma also provides Insight, which connects directly to our accounts and helps us keep track of our finances. For this feature, I think Mint at https://mint.com does a better job.
Just go to https://www.creditkarma.com and register an account.

If we want to buy a car, a house, or order a gas, water, electricity, or have a phone line under our name, then we need to keep an eye on our credit score and history. When I first came to the U.S., I thought that I would not have to care about my credit score because I would not buy anything I cannot afford at the time. Eventually, I realize that many other services require a good credit score, not just when we need to buy something.

Jan 16, 2014

Synchronize time using NTP on CentOS

If we run CentOS on a virtual machine, there will be time that the server time is off a few seconds or even minutes. We can install and use ntp to update server time:


yum -y install ntp

chkconfig --level 235 ntpd

service ntpd start

date

If we want to manually sync server time with a time server, then we need to stop ntpd service first, then use ntpdate to sync time:


service ntpd stop

ntpdate 0.centos.pool.ntp.org

ntpdate 0.pool.ntp.org

date

Log client's IP address in apache log when using HAProxy and ISPConfig

If we use HAProxy and ISPConfig to publish websites, by default, Apache log will log only the IP of the HAproxy server. To log client's IP in Apache log, we have to:

1. Config HAProxy
Add
option forwardfor to backend option in HAProxy config file, then reload haproxy
service haproxy reload
2. Change the LogFormat for ISPConfig site
Edit ispconfig config file nano /etc/httpd/conf/sites-available/ispconfig.conf Replace LogFormat "%v %h %l %u %t \"%r\" %>s %B \"%{Referer}i\" \"%{User-Agent}i\"" combined_ispconfig with LogFormat "%v %{X-Forwarded-For}i %h %l %u %t \"%r\" %>s %B \"%{Referer}i\" \"%{User-Agent}i\"" combined_ispconfig
3. Change the LogFormat for httpd
Edit httpd.conf file nano /etc/httpd/conf/httpd.conf Replace LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined with LogFormat "%{X-Forwarded-For}i %h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined Save the file and restart apache server service httpd restart
Check the log again. Not as other guides, I still keep the %h because we sometimes need to test the webserver directly. Also, we want to log if there is any other IP accessing our webserver besides the HAProxy.

Jan 3, 2014

VMware Tools are not running after cloning a CentOS VM

After cloning a CentOS virtual machine, the VM status may say that the VMware Tools are not installed and running. If we have installed the VMware Tools in the source VM, then the VMware Tools are still there, we just need to rerun the VMware Tools configuration script
/usr/bin/vmware-config-tools.pl

How to install GlusterFS on CentOS 6.5

1. Install from gluster repo
Install gluster repo


cd /etc/yum.repos.d/

wget http://download.gluster.org/pub/gluster/glusterfs/3.4/3.4.0/EPEL.repo/glusterfs-epel.repo

Install gluster server and client


yum install glusterfs-server

If we want to install only glusterfs client, then run


yum install glusterfs-client

Start GlusterFS


chkconfig --level 235 glusterd on

service glusterd start

2. Install from rpm packages
Download the packages for CentOS


mkdir /tmp/glusterfs

cd /tmp/glusterfs

wget -l 1 -nd -nc -r -A.rpm http://download.gluster.org/pub/gluster/glusterfs/LATEST/RHEL/epel-6.5/x86_64/

Install the GlusterFS packages


yum install glusterfs-3.4.2-1.el6.x86_64.rpm glusterfs-fuse-3.4.2-1.el6.x86_64.rpm glusterfs-geo-replication-3.4.2-1.el6.x86_64.rpm glusterfs-server-3.4.2-1.el6.x86_64.rpm glusterfs-cli-3.4.2-1.el6.x86_64.rpm glusterfs-libs-3.4.2-1.el6.x86_64.rpm