Archive for the ‘Web Hosting’ Category

Howto fix blank RDP Screen on Virtuozzo Windows Container

Tuesday, March 12th, 2013

Applies to:

Windows 2008 R2 Parallels Virtuozzo Containers

Description:

While logging into Administrator account through RDP on a VPS after a reboot, a blank screen or recycled svchost.exe property page is shown. Rebooting the VPS does not resolve the issue.

Cause:

This problem is caused by corruption of the Administrator account profile.

Solution:

On the hardware node run the following command from command prompt, in order to enter the container.

vzctl enter <Container_ID>

(Conatiner_ID can be obtained by running the vzlist –a command.)

Now you will get the C:\Windows\system32> prompt in the terminal, indicating that you have entered the container. In the C:\Windows\system32> prompt run the following commands, in order to create another account and make it a member of Administrators group on the container.

net user <username> <password> /add
net localgroup administrators <username> /add

Now RDP into the affected container, using this new username and password.

After you successfully login into the container, make sure from task manager that Administrator account is not logged into the container. If Administrator account is still logged into the container, then log off Administrator from Task Manager, running with elevated privilege.

Then copy all important files from C:\Users\Administrator folder to another folder for safekeeping and delete the C:\Users\Administrator folder.

Next login into the Administrator account. This account will use a temporary profile path due to absence of C:\Users\Administrator folder. Now create the C:\Users\Administrator folder again.

Then go to the windows Control Panel. Inside control panel select Small Icon view and click the User Accounts icon or link.

Inside User Accounts click on the Configure advanced user profile properties link on the left panel. It will popup User Profiles dialog.

Inside User Profiles dialog, select the Default Profile and then click Copy To button. It will pop up the Copy To dialog.

In Copy profile to section, browse and select the path C:\Users\Administrator and in Permitted to use section click change and select the Administrator user. Then click Ok.

Now the Confirm Copy message box will pop up with the message – “C:\Users\Administrator already exists. The current contents of this directory or this file will be deleted during this operation. Are you sure you want to continue?”. Click Ok to confirm.

Now logoff from Administrator account and login again. Now the account will use the permanent profile path C:\Users\Administrator and everything should be fine.
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Auto shutdown script for Xen VMs on XenServer

Monday, September 5th, 2011

In case of a scheduled maintenance which requires your Xen VMs to be shutdown on your Xen server when you are not available, the following script should can be put to use:

Create a script as allvmshutdown.sh with 755 permissions and add the list of VMs as in the example script:

#!/bin/bash
xe vm-shutdown vm=VM1
xe vm-shutdown vm=
VM2
xe vm-shutdown vm=VM3
xe vm-shutdown vm=VM4
xe vm-shutdown vm=VM5
xe vm-shutdown vm=VM6
xe vm-shutdown vm=VM7
xe vm-shutdown vm=VM8
xe vm-shutdown vm=VM9
xe vm-shutdown vm=VM10

To get a list of VMs on the server, run the command #xe vm-list from the command line, which will list the VMs hosted on your Xen host.

Now you just need to add a cron entry to schedule this job. For example, to run script at 02:00 am on Sunday:

crontab -e
*   02 *    *    0           /scripts/allvmshutdown.sh

Note: Do ensure that the script is commented or removed from the crontab, after the maintenance has been completed to prevent this script from recurring.

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Benefits of SSL communication

Thursday, August 18th, 2011

SSL is absolutely essential for any website collecting sensitive information online. On your computer, you can see it as the little padlock in the bottom right-hand corner of your browser, when you send or collect information online.

If you go to an unsecured website, you transmit information over many computers and networks, practically inviting hackers to steal this information – like passwords and credit card information. Obviously, that’s not something you want to fall prey to. SSL ensures that this does not happen.

What is SSL?

Secure Sockets Layer or SSL, was introduced in 1994 and has been declared as the standard for securing E-commerce transactions.  SSL is a protocol that encrypts credit card numbers and other sensitive information by scrambling the data so it can not be accessed by eavesdroppers.  More than likely, you have visited a few sites protected with SSL encryption as it is typically indicated by a URL that starts with HTTPS opposed to HTTP and a padlock icon located on the top or bottom of the web page.

SSL ensures safe transactions:

To make sure that no hacker can intercept and misuse information being collected online, SSL does two things:

  • Encrypts it with a hidden key on the user’s computer before the information is sent out;
  • Sends the key to the receiving computer using another encryption system called RSA. With this key the information collected online can be decoded.
    A 128-bit public encryption key and a 1024-bit private RSA key are unbreakable today. They are also part of most web browsers and web servers.

How does SSL  communication work:

    • Provides visible authentication:

      Before an SSL session is established, the server it connects with needs to have a digital certificate – a kind of unique digital identification to establish its authenticity. Digital certificates are issued by a Certification Authority, after performing several checks to confirm the identity of the organization to which it is issuing the certificate.

      An SSL digital certificate generates a public key for your customers and a private key on your server that works as a kind of official, online stamp for your enterprise. This private key needs to be kept secure, along with a back-up. A user can check to see if a secure session has been established by looking at the web address: in a secure session, the ‘http:’ portion of the web address changes to ‘https:’

        • Assures data integrity:

          This basically ensures that nobody can tamper with the data or information that is already online. Your customers will know that the contents of your website – or any information they have transmitted to it online – cannot be tampered with. It assures them that they are doing business in a safe environment.

            • Ensures data privacy:

              This means that online collection of sensitive information is secure and cannot be intercepted or read by anyone except the computer it was intended for.

              Data integrity and data privacy are integral to the functioning and success of any website handling or facilitating online financial transactions – and that’s what e-commerce is all about.

              Once a secure session has been established, the public key is used by customers, to encrypt the information being sent online. This information is then decoded instantaneously through your server’s private key.

              How to backup/restore Xen Virtual Machines using Xen Center

              Thursday, March 24th, 2011

              When you export a VM, a complete copy of the VM (including disk images) is stored as a single file on your local machine, with a .xva file extension. The VM export/import
              feature can be used in a number of different ways:

              • As a convenient backup facility for your VMs. An exported VM file can be used to recover an entire VM in the event of disaster.
              • As a way of quickly copying a VM, for example, a special-purpose server configuration that you use many times. You simply configure the VM the way you want it, export it, and then import it to create copies of your original VM.
              • As a simple method for moving a VM to another server.

              Note It may not always be possible to run an imported VM that was exported from another server with a different CPU type. For example, a Windows VM created on a server with an Intel® VT Enabled CPU, then exported, may not run when imported to a server with an AMD-VTM CPU.

              To export a VM:

              1. If the VM you want to export is running, you must shut it down first. See the image below:
              2. In the Resources pane, select the VM, right-click, and then click Export as Backup on the shortcut menu. Alternatively, on the VM menu, click Export as Backup.
              3. Enter a name for the export file and specify the folder where you want it to be saved.
              4. To have the export file verified, select the Verify export on completion check box at the bottom of the dialog box. Be aware that verification may take some time.
              5. Click Save to begin exporting the file.
              6. The export progress is displayed in the status bar at the bottom of the XenCenter window and on the Logs tab. To cancel an export in progress, click on the Logs tab, find the export in the list of events, and click the Cancel button.

              Exporting a VM may take some time, depending on its size and the speed and bandwidth of the network connection between the server and XenCenter.

              To import an external VM in XenCenter, you use the Import wizard: select a server or pool in the Resources pane, right-click, and then select Import VM on the shortcut menu, and follow the wizard steps.

              1. Import source. Enter the location of the exported VM in the Import file name box and ensure that the Exported VM option button is selected. Click Next to continue.
              2. Home server. Select a home server for the new VM, then click Next to continue.
              3. Storage. Select a storage repository where virtual disks for the new VM will be stored, then click Import to begin the import process.
              4. Network. Configure the virtual network interfaces for the imported VM. The default network interfaces are listed on this page; you can add, modify, or delete virtual network interfaces as required. When you are happy with the new VM’s network configuration, click Next to move to the final wizard page.
              5. Finish. To have your new VM start up as soon as the import process has finished and the new VM is provisioned, ensure the Start VM after import check box is selected before  you click Finish.

              Click Finish to complete the import process and close the wizard.

              The import progress is displayed in the status bar at the bottom of the XenCenter window and also on the Logs tab. The import process may take some time, depending on the size of the VM and the speed and bandwidth of the network connection between XenCenter and the server where you are installing the new VM.

              Once the newly-imported VM is available, it appears in the Resources pane. This is in a nutshell, the simplest way to backup your VMs if you are the administrator of a Xenserver. There are advanced tools available like PHDVirtual, which automates the backup and transfer of your VMs to an external storage and though their pricing is a bit steep its well worth the price for the convenience and automation offered.

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              Checklist of recommended best practices for your office email server

              Wednesday, February 2nd, 2011

              Having a latest hardware with leased internet connectivity and a feature rich email client are not the only requirements you need to setup your office email server. Unless you can send mails to your clients, partners and associates across the globe, your mail server is of no practical use. It is the trustworthiness of your mail server over the Internet that is standing between you and the recipient.

              To be a trusted E-mail sender we need to follow the best practices which are highlighted below:

              1.  Messages from IP (No Domain)

              Messages should be from a domain and not from any IP Address. e.g. user@domain.com is a valid sender, whereas user@192.168.0.18 is an invalid sender and thus the mail will be rejected.

              2.  Mail Servers on Dynamic/Dial-up Addresses

              The sender server IP Address must not be a dynamic IP. Normally all IP addresses should have a correct reverse DNS, and especially email servers. Most Anti-Spam tools will reject email from places whose reverse DNS looks not to belong to an email server, but more likely to be a home or office dynamic address. If you are running an email server, make sure the Reverse DNS of the IP address reflects your domain, e.g.  ‘gateway.yourdomain.com’ or ‘mail.yourdomain.com’.

              3.  Valid FROM domain

              The FROM address is important as it is the address that would be used if problems were encountered delivering the message, so if the address can’t be responded to, the E-mail cannot be accepted from that address either.

              e.g. user@yourdomain.com is an accepted sender but the following bad examples will get rejected:

              user@localhost
              user@192.168.1.200
              user@myfakedomain.not

              4.  The sender server must identify itself and the identification must be Valid (Valid HELO)

              Most email servers and anti-spam tools will not allow mails to be received unless the above protocol is in place. This practice does not supply enough information to safely identify the server and responsible party, if a problem email is received. And almost every mail server offers this capability. This is a simple rule which just insists that the HELO (or EHLO) is sent with every email connection and it is properly formatted.

              In order to ensure that messages are not stopped by this check, make sure the HELO is a FQDN.The HELO string sent should in the style of:

              HELO mta1.mycompany.com

              The following bad example(s) will get rejected:

              HELO
              HELO localhost
              HELO hostnameonly
              HELO 192.168.1.1 (just an IP)

              If you are the one who is not receiving emails or are unable to send mail to some of your recipients, you may ask them to check if they really follow these practices.

              At Diadem Technologies, we provide secure and reliable hosted email solutions on shared, dedicated and virtual servers. With over 10,000 hosted mailboxes and a decade of expertise, we have the right solution for your needs. Please visit our website or drop us a line for more details.

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              The new Plesk 10 hosting control panel – Our first impressions

              Wednesday, January 26th, 2011

              As a loyal customer of Parallels for the past 7 years who has been using the Industry standard hosting control panel, Plesk for our web hosting automation needs, we are excited with the latest release of their control panel – Panel 10. In the past few weeks we have been evaluating Parallel’s new release of Plesk Panel version 10. It is pretty good with respect to managing user level permissions. From this version onwards, web hosters would need to maintain the recommended user hierarchy while creating users, E.g. Reseller > Client/Customer > Domain/Subscription. Domain Administrator feature has been deprecated and a role based user access level has been created, e.g. certain users can only configure email ids, some users cannot access ftp options and so on.

              Another feature which has been added in the Linux version of Plesk is the option to create additional FTP users, which will benefit organisations which require additional ftp users with restricted access to their folders and a primary admin user to manage the individual ftp users from a single console.

              New client dashboard with an enhanced menu system. The new menu is more user friendly and faster access with respect to earlier Plesk versions.

              The above screenshot is for the user (role) creation for grant/deny of particular service(s).

              The most awaited new feature “Additional FTP Account”, which can be control with a Main FTP user.

              An improved application vault for installing your favourite open source applications like WordPress, Joomla and much more.

              Some of the key features of Plesk 10 is highlighted below:

              Separate administrator user interface – Parallels Plesk Panel now comes with a separate administrator interface, optimized for server and business management.

              Control panel improvements – Performance improvements for control panels make pages load much faster.

              Upgradable Apache configurations – Your customized Apache configurations will now remain in force when you upgrade.

              Role-based access – Customer administrators can specify application access based on user roles, enabling them to easily limit access to only those users who need it.

              Improved security and performance – FastCGI lets you isolate sites in a shared hosting environment with greater account density than suPHP.

              Improved password security – Assignment of random default passwords and a password strength indicator protect your servers from hackers and lower support costs attributable to broken passwords.

              More flexibility in hosting plans – New and more flexible hosting concepts support a superior growth path to the future. Key features include multi-domain hosting; ability to assign multiple add-on plans to a subscription; and ability to automatically update subscription settings when plans change.

              Intuitive and modern SiteBuilder (free with Parallels Plesk Panel Unlimited licenses) – The brand-new SiteBuilder, rebuilt from the ground up, enables instant Web site creation. It includes point-and-click and drag-and-drop capabilities, complete with content appropriate for different small business types and personal interests.

              Like most web hosters, we are hopeful that the new version would allow our clients to get more out of their hosting plans and we intend to upgrade our clients to the new version in a phased manner over the next few months. Feel free to share your views on the new Plesk 10 panel.

              Links for more information on Plesk 10:

              http://www.parallels.com/products/plesk
              http://www.parallels.com/products/plesk/new
              ftp://download1.sw-soft.com/Plesk/PP10/Doc/

              Shared Versus Dedicated Web Hosting

              Wednesday, November 10th, 2010

              Your Web hosting company can be your site’s best friend or worst enemy – depending on the level of service and responsiveness. A successful Web site depends on a good Web host, but it’s just as important to select the right kind of hosting account.

              Are you willing to share space on a server with other sites or do you need a server of your own? Know the answer before you make a decision.

              Shared Hosting Services

              Unique And Shared IP Addresses

              Every server connected to the Web has its own IP address. The IP address uniquely identifies that server much like a membership number or driver’s license number identifies a particular individual. IP addresses are also tied to domain names. This relationship means that Web users can either enter a domain name or an IP address in a Web browser to access the information on a Web server.

              The basic difference between Web hosting accounts is whether a site has its own server or shares one with other Web sites. That arrangement determines whether the site has its own IP address or shares one with other sites.

              Most small to medium-sized sites use a type of hosting called “virtual hosting” where a number of Web sites reside on the same server. Because the sites share a server, they also share an IP address.

              Large and/or busy sites usually can’t share server space because the volume of Web traffic from many sites would quickly overwhelm the server. Those sites either operate their own servers or select a “dedicated hosting” option from their Web host. Dedicated hosting means that your site is the only site residing on the server and so you aren’t sharing an IP address with any other site.

              Which type is best for you? Let’s look at the good and bad points of both.

              The best thing about virtual hosting is price: it’s usually really low. Depending on your site’s technology, storage, and bandwidth requirements, virtual hosting can cost anywhere from Rs. 999 per year to Rs. 9999 per year depending on your space and feature requirements. If price is your main concern, then virtual hosting may be right for you.f you run a small business and don’t expect more than 1000 visitors to your website per day, then shared hosting is for you.The only problem with shared hosting is that bandwidth is limited, so if your site becomes very popular you might find yourself running out of bandwidth quickly. But make sure you’re aware of potential problems:

              Know your neighborhood: Sharing an IP address with known spam sites or adult sites raises a warning flag with search engines. Spam sites try to trick search engines into giving them an underserved high rank, so some search engines like AltaVista respond by banning the entire IP address from their index.

              Check your Web host’s terms of service page to see what sites are allowed on their servers. Also ask if they offer an individual IP address for different sites on the same server. Some hosts do, but make sure the IP address and domain name resolve correctly before you start promoting the site.

              Server response : Some web hosts provides free hosting service for a limited period from where you can judge the server performance and the features they would provide you for your hosting service.

              Dedicated Servers

              Dedicated hosting is the opposite of shared hosting. Dedicated hosting is about you being in total control of the server and what goes on the server. You decide whether to host 1 site or 10 of your sites.Dedicated hosting allows you to tailor database, email and software applications to your desire – so it works the way you want it to. This is powerful.Dedicated hosting is ideal for websites with high traffic and large businesses who want complete control over the server so they can fine tune there applications, etc.

              Another benefit of dedicated hosting is you can resell the space/bandwidth to people who want to setup their own website.Unlike shared hosting, dedicated hosting will cost considerably more and a monthly payment.If your website is critical to your business, then it is highly recommend that you opt for a dedicated hosting.

              Benefits of Dedicated Hosting

              • More control: You don’t have to worry about someone’s bad script slowing or crashing the server. You have only yourself to blame if that happens!
              • Faster response with high traffic loads. Because the server only responds to request for information from your site, visitors won’t have to wait in line to view your Web pages and images.
              • No bandwidth penalty. Virtual hosting accounts usually offer a certain amount of bandwidth per month to each site on the server. Sites that go over their allotment get charged extra. But dedicated hosting generally has no such restrictions because it’s assumed you need a lot of bandwidth if you require your own server.

              Evaluate your needs and your financial resources before you sign up for hosting and choose your host carefully.

              To know more about various hosting options, pricing  and how it could enhance your web presence  you can visit our website or write in your queries to info@diadem.co.in

              Email and server security features on Diadem servers

              Thursday, October 14th, 2010

              Diagram of Various Tiers of security in datacenter network and at server level

              security


              At Diadem Technologies we take extreme precaution and safeguard of our mailing services to ensure continuous and reliable availability of our mailing services to our clients. We have all our servers located in the world’s leading datacenter which has a very secure environment with various levels of physical and hardware based protection to keep your data safe from different attacks and vulnerabilities. The servers have multi core Xeon processers and have RAID10 array of HDDs for complete data redundancy so that a hard disk crash would not affect the server operations and would not result in any loss of data on the server.

              The servers are restricted to be accessed via the Public network so that no unauthorized access to the servers can be made. We use a secure encrypted VPN (virtual private network) connection that connects to the private backend network and hence the servers are only accessible to the legitimate admin users at our end.

              For network level protection we have in place perimeter hardware firewalls by CISCO systems to block external threats along with CISCO GUARD DDOS (Distributed Denial of service) and CISCO Tipping point IPS (Intrusion prevention system). CISCO GUARD DDOS protects from requests that make a computer resource unavailable to its intended users and brings down the server to halt. CISCO Tipping point IPS is an advanced Intrusion prevention system that is used extensively in critical networks to monitor network and/or system activities for malicious or unwanted behavior and can react, in real-time, to block or prevent those activities. Network-based IPS, for example, will operate in-line to monitor all network traffic for malicious code or attacks. When an attack is detected, it can drop the offending packets while still allowing all other traffic to pass.

              After passing through the various levels of security mentioned above we have more additional security features on the physical server for protecting the server /server applications and the inbound and outbound mails.

              • At the server we have robust software based firewalls that have been customized to add another level of security in the server.
              • We have SMTP connection tracking system to check all the connections that are being made to the server for sending or receiving mails. At this level various parameters of a mail are checked like if the IP of the sender is blacklisted in any third party Anti SPAM website, if the sender has a valid mail server, if the reverse DNS of the sender email server is valid.
              • We have enabled greylisting on the server to cut down on SPAM mails before they can enter the server. We have advanced content filtering along with anti spam software, antivirus, malware and anti root kit signatures that are updated regularly to block emerging threats immediately.
              • Once the mail is scanned with the above filters, we implement a new and unique technique to authorize defined servers only to server your emails through the use of SPF records. Any other servers would not be able to send or receive any mail on behalf of your domain. This will cut down spoofing of your emails.
              • At the last stage we have SMTP authentication enabled that allows mails to be relayed through our servers only for those who are intended to send mails hence reducing the unwanted relaying of mails.

              The above illustration highlights our commitment to ensure that we provide our clients with the best of breed technologies to ensure spam free, virus free, efficient and continuous availability of our mailing services for their operations.

              If you are interested in knowing more about our web hosting services and plan details, you can look us up at www.diadem.co.in.

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              SA-SCSI Storage with RAID – Now Available on our VPS Servers

              Monday, August 30th, 2010

              In line with our sustained efforts in providing our VPS clients with industry leading hardware and software options, we have upgraded the HDDs on our VPS servers from the current Raptor 10K RPM disks to Seagate Cheetah SA-SCSI 15k RPM drives.

              SA-SCSI (Serial Attached Small Computer System Interface) is the gold standard in storage solutions for web servers requiring enterprise class robustness with high availability and fault tolerance features, especially where large databases and mission critical applications are involved. To ensure our clients are able to get the performance of a dedicated hardware at a fraction of its cost, we  have gone ahead and upgraded all our VPS clients to the new hardware without any additional expense and they are all delighted with the improved performance which is being delivered to their applications, as a result of this upgrade.

              The SCSI HDDs coupled with the RAID hardware makes it a very stable and robust platform for hosting VMs on the Citrix Xen Server platform. Furthermore, we have also upgraded the Xen Server virtualization platform to its latest version (Xen Server ver 5.6) which is more stable and has several bug fixes implemented in its current verion. We have also added more storage space to our VPS hosting plans alongwith a higher monthly bandwidth allocation for no additional charges.

              Bottom line is that if you are looking for a VPS or would like to host your application, website or mail server on a dedicated server platform, you will be hard pressed to find an offering which could better ours!

              Check out our new Linux VPS and Windows VPS hosting plans and talk to our sales team today!

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              New Web Hosting Plans for Linux and Windows 2008

              Friday, August 27th, 2010

              In sync with the launch of our new website, we have also revamped our shared web hosting plans for both Windows 2008 Enterprise and Linux platforms and the new hosting plans are now available online. The new hosting plans have enhanced web space, bandwidth and email id allocations amongst other updates and the key benefits are given below:

              • No limits on mailbox quotas: You can now define your own mailbox capacity on a per mailbox basis and the total storage limit allocated on your domain would apply for all users on your domain.
              • No limits on web hosting space: For Linux hosting plans, we have removed web hosting space limits. The total applicable limit on your hosting plan can be used your website, emails or a combination of both, as per your choice.
              • Additional mailboxes: Starting with the SOHO plan onwards, we have increased the no. of mailboxes on every hosting plan by as much as 50% than our previous hosting plans for no additional charges.
              • Latest OS & Control Panel: Industry leading Plesk 9.5 control panel is available to all our clients. We also host ASP/ASP.net enabled websites on Windows 2008 Enterprise Edition for enhanced performance and IIS 7 Support.
              • More server storage space: We have upped storage limits on our hosting plans by nearly 50% across the board. The additional storage space is matched by the upgraded hardware to make your websites and applications run better and faster.

              These feature enhancements coupled with our commitment to providing our clients with the most responsive hosting support team in the country clearly makes it a win-win deal for our clients.

              Want to learn more? Check out our new Linux and Windows 2008 enterprise hosting plans and signup online.

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