Problem: After fail2ban install, everything works fine, but after reboot fail2ban does not start. Manual /etc/init.d/fail2ban restart fails also.

Cause: Fail2ban looks for fail2ban.sock in
/var/run/fail2ban/
During reboot, that directory is removed. Fail2ban assumes it is there and fails on restart.

Solution: Make sure the directory exists during start of fail2ban. Edit the init.d for fail2ban to fix this.
sudo vi /etc/init.d/fail2ban
Find the do_start option.

do_start()
{
# Return
# 0 if daemon has been started
# 1 if daemon was already running
# 2 if daemon could not be started
do_status && return 1

return 0
}

Add the following after the if statement.

Finally, it should look like this

do_start()
{
# Return
# 0 if daemon has been started
# 1 if daemon was already running
# 2 if daemon could not be started
do_status && return 1

return 0
}

Now restart and it should work.

sudo /etc/init.d/fail2ban restart

Just for kicks, see how /var/run has the newly created fail2ban directory.

sudo ls /var/run


Steps
1. sudo vi /etc/apparmor.d/usr.sbin.mysqld
2. Add
/newdir/ r,
/newdir/** rwk,
3. sudo /etc/init.d/apparmor restart
4. sudo /etc/init.d/mysql restart

If that still does not work, check the nix permissions to be sure mysql is owner and group for the new directory recursively.

sudo /usr/bin/vmware-config.pl

sudo dpkg-reconfigure mysql-server-5.0

It will allow you to reset your root password without messing with the data or any other configuration in my.cnf.

“Could not reliably determine the server’s fully qualified domain name, using 127.0.1.1 for ServerName”
or
“[warn] _default_ VirtualHost overlap on port 80, the first has precedence”

you need to make sure a couple of lines are in your /etc/apache2/httpd.conf  file.

ServerName localhost
NameVirtualHost *:80

Then we decided to load the database onto other servers for more data points on this Mysql performance test. We ran the same query returning 429 rows of data with 13 table joins and a couple of sub-queries. All queries were run on the command line client on the servers themselves to avoid network lag.  All servers are running Mysql 5.0.x.

Results

1. Ubuntu Linux: 0.70 seconds
2. CentOS: 0.78 seconds
3. Windows 2003 Server: 1.40 seconds
4. Windows 2003 Server: 1.42 seconds

Server hardware

1. Ubuntu Linux
AMD ATHLON 64 X2 4200+
2GB DDR400
200GB 7200RPM SATA/150

2. CentOS
Dual Opteron 240
2GB DDR ECC
120GB 7200RPM SATA/300

3. Windows 2003 Server
Dual Xeon
2GB DDR ECC
7200RPM PATA

4. Windows 2003 Server
2 Dual Xeon (4 CPUs)
8GB DDR ECC
3 73GB 10,000RPM SCSI in RAID 5

A followup to the benchmark that clarifies the cause of the differences

So what can you speed up the load time for your site.  For one thing, if you are using more advanced technology than static HTML files, which most site are in this category these days, you need to make sure the server hosting the site is fast enough.  A lot of sites are running on the cheapest shared web hosting services and as we all know, the cheapest is not always the best.  These services do give you a lot on paper, but with their bogged down servers you will never be able to utilize half the resources they allow for your account.

Now, if your hosting service or your own server is plenty fast with enough bandwidth, then it is time to look closer at the details.  Like I mentioned before, if you are running a static HTML site, these tips will not help you.  But you do have many other problems of how on earth will you update your content or design across the entire website.  That is another post.  But for the majority of us using databases to generate dynamic content, the database is a big culprit in site latency.  Databases need to be optimized for the hardware and the application it is running.  Optimizing a database starts from the design of the schema to the implementation of regular maintenance processes.  Again, there can be books written on how to optimize a database and maybe I will write one someday.

Anyhow, if you are running a site that is slow, don’t just ignore it.  Spend some time to figure out why it is slow and solve the issue.  It would be a shame to lose all those potential visitors to slow load time.

$ service httpd -D SSL -k start

Also, I found that restart does not always take new changes to my conf files.

$ service httpd -D SSL -k restart

Instead, use the stop then the start command to be sure.

$service httpd -D SSL -k stop
$service httpd -D SSL -k start

That was a source of much pain while working on this particular server.