Author: The Geek Decoder

WHM Setup Options

November 28, 2014 The Geek Decoder No Comments cPanel, WHM

Email Settings Auto Discovery

Enable: This will allow email clients to automatically locate and configure themselves based on the server’s configurations.

No, thank you: This will prevent the auto setup features on email clients from automatically locating and configuring themselves.

Email Archiving

Enable: This will allow users to configure the retention period for incoming, outgoing and mailing list emails. You can enable the archiving feature through the cPanel interface on a per-domain basis. Messages can be retrieved through the following methods:
IMAP connection
Downloading the messages directly
WebMail
Mail Delivery Reports feature in WHM

No, thank you: This will prevent the server from retaining messages being sent. Additionally, these options to control the archive type and retention period per domain will be removed from cPanel.

Query Apache for “Nobody” Senders

Enable: This will allow you to query the Apache servers status to determine the true sender of the email. By looking at the process table to determine who really sent the message, cPanel can accurately report the sender of the message. While this requires more process time, it is more reliable and cannot be forged.

No, thank you: This will prevent mail delivery process from querying the Apache server to determine the true sender of a message when the user who sent the message is ‘nobody’.

Security Tokens

Enable: This will allow cPanel and WHM to secure their URLs from being affected by Cross-Site Request Forgery (XSRF) attacks by adding unique tokens to the URL upon login.

No, thank you: This will prevent the use of unique security tokens that would otherwise be displayed in the URL upon login. This is not recommended and will leave you vulnerable to XSRF attacks.

SMTP Restrictions

Enable: This will prevent users from sending mail openly without any restrictions. This feature configures your server so that the mail transport agent (MTA), Mailman mailing list software and root user are the only accounts able to connect to remote SMTP servers.

No, thank you: This will allow users to send mail openly without any restrictions. This is not recommended if you want to keep your users’ mailing restricted.

Trust X-PHP-Script for ‘nobody’ senders

Enable: This will allow the server to trust the X-PHP-Script headers to determine the sender of email sent from processes running as “nobody.” The server will trust messages which contain X-PHP-Script headers (this requires the Easy Apache option MailHeaders to be compiled in Apache) and use them to determine the true sender.

A sophisticated, malicious user can forge email headers. Although it may be more CPU intensive, the Apache query method is recommended if you do not trust your users.

No, thank you: This will prevent the server from checking the mail headers for X-PHP-Script headers to determine whether or not the email can be trusted and identified as a true user.

Smartctl on Linux

November 27, 2014 The Geek Decoder No Comments Administration, Hardware

SMART (Self-Monitoring, Analysis, and Reporting Technology) allows you to see the status or overall health of a hard drive. This information is instumental in providing warning signs of problems with a hard drive.

All Linux distributions provide the smartmontools package, which contain the smartctl program used to display SMART information from attached drives. This package also provides the smartd daemon which periodically polls the drives to obtain SMART information.

Using smartd is essential as it can let you know immediately when a SMART attribute fails.

With the -i option, you can view the type of drive, its serial number, and so forth. In a system with a lot of drives, having this information recorded can assist in knowing which drive device (i.e., /dev/sda) corresponds with which physical drive.

Install:

# yum install smartmontools

Now start the service of Smartctl. 


#service smartd start 
# chkconfig smartd on

To enable Smart Capability for the disk run below command. 

#smartctl -s on /dev/sdb

To disable Smart Capability for the disk run below command. 


#smartctl -s off  /dev/sdb

To display details Smart info for the disk run below command. 


#smartctl -a /dev/sdb              // For IDE drive
#smartctl -a -d ata /dev/sdb       // For SATA drive

To begin, see what the drive details are:


[root@austin ~]# fdisk -l

Disk /dev/sda: 250.0 GB, 250000000000 bytes
255 heads, 63 sectors/track, 30394 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          62      497983+  83  Linux
/dev/sda2              64         584     4184932+  82  Linux swap / Solaris
/dev/sda3             585       30390   239416695   82  Linux swap / Solaris

Now we know the single drive is sda. Also, you can usually identify which hard disks are on your system by
looking in /proc/ide and in /proc/scsi.

# smartctl -i /dev/sda

root@austin ~]# smartctl -i /dev/sda
smartctl 5.43 2012-06-30 r3573 [x86_64-linux-2.6.32-504.el6.x86_64] (local build)
Copyright (C) 2002-12 by Bruce Allen, http://smartmontools.sourceforge.net

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital RE3 Serial ATA
Device Model:     WDC WD2502ABYS-18B7A0
Serial Number:    WD-WCAT19910234
LU WWN Device Id: 5 0014ee 157014252
Firmware Version: 02.03B04
User Capacity:    250,000,000,000 bytes [250 GB]
Sector Size:      512 bytes logical/physical
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   8
ATA Standard is:  Exact ATA specification draft version not indicated
Local Time is:    Thu Nov 27 16:10:20 2014 MST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

[root@austin ~]# smartctl -i /dev/sda
smartctl 5.43 2012-06-30 r3573 [x86_64-linux-2.6.32-504.el6.x86_64] (local build)
Copyright (C) 2002-12 by Bruce Allen, http://smartmontools.sourceforge.net

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital RE3 Serial ATA
Device Model:     WDC WD2502ABYS-18B7A0
Serial Number:    WD-WCAT19910234
LU WWN Device Id: 5 0014ee 157014252
Firmware Version: 02.03B04
User Capacity:    250,000,000,000 bytes [250 GB]
Sector Size:      512 bytes logical/physical
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   8
ATA Standard is:  Exact ATA specification draft version not indicated
Local Time is:    Thu Nov 27 16:14:54 2014 MST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

Now, edit /etc/smartd.conf and add entries for your drives:


/dev/sda -d ata -H -m root
/dev/sdb -d ata -H -m root

Turn the service on:


# chkconfig smartd on
# service smartd start

The smartctl program also allows for you to view and test SMART attributes of a drive. You can quickly check the overall health of a drive by using:

# smartctl -H /dev/sda

smartctl can be used to initiate long and short tests for the drive. These should be run periodically to do quick, or full, self-tests of the drive:


# smartctl --test=short /dev/sda
# smartctl --test=long /dev/sda
# smartctl -a /dev/sda

More info : https://wiki.archlinux.org/index.php/S.M.A.R.T.

Plesk install Fails on Windows

November 27, 2014 The Geek Decoder No Comments Plesk

The update of Parallels Panel has failed: “Syntax error in file panel.inf3: Error parsing Element”

Cause

The issue is temporary and caused by network connectivity issue to one of the autoinstaller mirrors.
Resolution

As a workaround use another autoinstaller mirror, add the following IP addresses for autoinstall-win.pp.parallels.com to the hosts file:

93.184.221.133 US, Kansas
68.232.34.73 US, California
72.21.81.253 US, California
46.22.75.111 EU, United Kingdom
72.21.89.132 EU, Germany

For example:

93.184.221.133 autoinstall-win.pp.parallels.com

Migrate Plesk IP’s to New Plesk server

November 26, 2014 The Geek Decoder No Comments Plesk

When Migrating from an old dedicated server to a new server, you can ask your hosting provider to migrate the data and the IP’s. Here is the strategy to move them.

  1. ssh to the old and new server.
  2. One the old server, change the following:

Edit /etc/sysconfig/network-scripts/ifcfg-eth0

# cd /etc/sysconfig/network-scripts

# nano ifcfg-eth0

# =============================================================
# Network Interface Script generated by BareMetal
# =============================================================
DEVICE=eth0
BOOTPROTO=STATIC
ONBOOT=yes
IPADDR=216.xx.xxx.xx
NETMASK=255.255.255.0
HWADDR=6C:xx:xx:xx:xx:xx

[stextbox id=”info”]* IP and Mac changed to xx. Yours will have the real IP and mac address.[/stextbox]

# service network restart

Change the primary IP – ifcfg-eth0 on the old server to a temp one – one assigned for a place holder so you can access the panel.

3. Do the same on the new server, adding the IP from the old server to /etc/sysconfig/network-scripts/ifcfg-eth0
Edit /etc/sysconfig/network-scripts/ifcfg-eth0

# cd /etc/sysconfig/network-scripts

# nano ifcfg-eth0

# =============================================================
# Network Interface Script generated by BareMetal
# =============================================================
DEVICE=eth0
BOOTPROTO=STATIC
ONBOOT=yes
IPADDR=216.xx.xxx.xx
NETMASK=255.255.255.0
HWADDR=6C:xx:xx:xx:xx:xx

# service network restart

Now the old server has a temp IP and the new server has the old server primary IP.

Login to plesk on the old server and assign the new temp IP to all the domains. Remove the other secondary IP’s from plesk.

Login to plesk on the new server. Add the secondary IP’s from the old server. Assign the IP’s to the domains according to their DNS records.

Remove any IP’s on the new panel that were assigned, but will not be used.

Add Wildcard SSL or multi-domain or UC/SAN SSL certificate

November 22, 2014 The Geek Decoder No Comments cPanel, SSL Certificates

What is a multi-domain or UC/SAN SSL certificate?

Multi-domain certificates are SSL certificates that allow you to secure multiple, potentially unrelated domains with a single certificate. This includes UCC/SAN certificates and wildcard certificates. Unified Communications/Subject Alternate Name (UC/SAN) Certificates are SSL certificates that allow you to specify a list of hostnames that the same certificate protects.

Note:

Icon

You must reissue these certificates each time that you add a new hostname.

What is a wildcard SSL certificate?

A wildcard certificate allows you to install the same certificate on any number of subdomains if they share an IP address. You can apply a wildcard certificate to services in WHM’s Manage Service SSL Certificates interface (Home >> Service Configuration >> Manage Service SSL Certificates).

  • For example, if you have a wildcard certificate for  
    *.example.com

    , you can use it to securely connect to 

    mail.example.com

     and 

    www.example.com

    , but not to 

    example.com

    .

  • The  
    root

     user may install a wildcard certificate on a collection of subdomains that are associated with a single root domain on multiple IP addresses. If multiple IP addresses are used, a user on the server must not own the 

    root

    domain.

What is the difference between a wildcard and a webserver certificate?

Webserver certificates only allow you to secure a single domain. Wildcard certificates allow you to secure a domain and an unlimited number of subdomains. For example, if you wish to secure 

store.example.com

 and 

blog.example.com

, you can use a single wildcard certificate to do so. However, each subdomain will require its own dedicated IP address.

Subdomain Creation Error in cPanel

November 22, 2014 The Geek Decoder No Comments cPanel

You go to create a subdomain and get the following errors.

[stextbox id=”warning”]There was a problem creating the sub-domain: You do not have permission to create subdomains of the server’s hostname[/stextbox]

Or
[stextbox id=”warning”]The system experienced a problem during the creation of the “example” subdomain.[/stextbox]

This was fixed by changing settings in WHM: WHM Home -> Server Configuration -> Tweak Settings

Allow users to park subdomains of the server’s hostname: ON