Tips for Virtual Private Server

[Nitro]

Understanding the Registry :

Registry is the complete repository information of the system.
The Windows 9x/ME/NT/2000/XP Registry is a complex, unified, system wide, continually referenced during operation database, used for centrally storing, locating, editing and administering system, hardware, software and user configuration information, following a hierarchical structure.
It was introduced to replace the text/ASCII based MS-DOS configuration (.BAT, .SYS) and MS Windows initialization (.INI) files.

Registry Structure :

Registry is divided into five separate structures that represent the Registry database completely. These five groups are known as Keys and they are as below given ;

1) HKEY_CURRENT_USER
This registry key contains the configuration information for the user that is currently logged in. The users folders, screen colors, and control panel settings are stored here. This information is known as a User Profile.
2) HKEY_USERS
In windowsNT 3.5x, user profiles were stored locally (by default) in the systemroot\system32\config directory. In NT4.0, they are stored in the systemroot\profiles directory. User-Specific information is kept there, as well as common, system wide user information.
3) HKEY_LOCAL_MACHINE
This key contains configuration information particular to the computer. This information is stored in the systemroot\system32\config directory as persistent operating system files, with the exception of the volatile hardware key.
4) HKEY_CLASSES_ROOT
The information stored here is used to open the correct application when a file is opened by using Explorer and for Object Linking and Embedding. It is actually a window that reflects information from the HKEY_LOCAL_MACHINE\Software subkey.
5) HKEY_CURRENT_CONFIG
The information contained in this key is to configure settings such as the software and device drivers to load or the display resolution to use. This key has a software and system subkeys, which keep track of configuration information.
Each of these keys is divided into subkeys, which may contain further subkeys, and so on. Any key may contain entries with various types of values. The values of these entries can be ;
- String Value
- Binary Value (0 or 1)
- DWORD Value, a 32 bit unsigned integer
- Multi-String Value
- Expandable String Value

Editing Registry :

Always make sure that you know what you are doing when changing the registry or else just one little mistake can crash the whole system. That’s why it’s always good to back it up !
To view the registry (or to back it up), you need to use the Registry Editor tool. There are two versions of Registry Editor ;

To modify the Registry, you need to use a Registry Editor as :

- Start
- Run
- Regedit.exe (Windows 95/98/ME/NT/2000/XP) = located in %WinBootDir% (%SystemRoot%) has the most menu items and more choices for the menu items. You can search for keys and subkeys in the registry.
- Regedt32.exe (Windows NT/2000/XP) = located in %SystemRoot%\System32,enables you to search for strings, values, keys, and subkeys. This feature is useful if you want to find specific data.

What is REG Files ?

.reg file, which can be in the for of ;
- Plain text/ASCII format in Windows 95/98/ME and NT/2000/XP or
- Binary format in Windows 2000/XP
Text .REG files can be easily viewed/created/edited by hand using any text/ASCII editor, like Notepad.
Their purpose is to add, modify or delete Registry (Sub) Keys and/or Values.

What does Private refer to in Virtual Private Server ?

On a node each VPS Hosting gets its own portion of resources, which are usually guaranteed to be available to that particular VPS Hosting. For instance, the host server (node) may have 8GB of ram, and 256mb (for instance) could be guaranteed to be available to a VPS Hosting. That would mean that regardless of what other VPS Hosting’s on the same server use, that amount of RAM will be available to the VPS Hosting. Also, each VPS Hosting runs completely independent of eachother. Each VPS Hosting has its own filesystem so a VPS Hosting can’t see any of the data of another VPS Hosting. Also each VPS Hosting has it’s own server load, can run its own Operating System, can be rebooted individually, and so on. Basically by the end user it can be treated as a dedicated server.

mod_rewrite: could not create rewrite_log_lock

While restrating apache if you are getting below mentioned error

————————————————†”—————————–
No space left on device: mod_rewrite: could not create rewrite_log_lock
————————————————†”—————————–

Do this to fix it (replace “apache� with the name of the user apache runs as):

ipcs -s | grep apache | perl -e 'while () { @a=split(/s+/); print `ipcrm sem $a[1]`}'

That will solve your problem.

Virtuozzo over OpenVZ

Virtuozzo is SWsoft’s virtualization and automation solution built on top of OpenVZ. Differently from OpenVZ, Virtuozzo provides improvements and additional functionality in the areas of density, management tools, recovery, and other areas. Specific benefits of Virtuozzo compared to OpenVZ can be found below:
* Higher VPS Hosting density. Virtuozzo provides efficient memory and file sharing mechanisms enabling higher VPS Hosting density and better performance of VPS Hostings.
* Management Tools. Virtuozzo ships with number of management, monitoring, troubleshooting, and administration tools significantly reducing management, administration, and deployment costs.
* Specific tools include VZMC — GUI-based administration, management, monitoring, and provisioning tool.
* VZCC — browser-based administration, management, monitoring, and provisioning tool.
* PowerPanel — browser-based recovery and administration tool for VPS Hosting owner.
* Number of additional shell utilities.
* Support and Maintenance. Virtuozzo™ is a commercial product supported and maintained by SWsoft with options for 24×7 phone support and guarantees on maintenance schedules.
* Advanced Recovery, Monitoring, and Back-up tools.
* Physical-to-VPS Hosting and VPS Hosting-to-Physical migration tools. Those tools allow easy conversion of existing physical machines into Virtuozzoâ„¢ VPS Hosting (and vice-versa) facilitating the adoption of virtualized infrastructure.
* Common client-server XML-based management API (VZAgent). API allows easily integration of Virtuozzo into existing management infrastructure and development of additional management and monitoring modules.
* Traffic accounting tools. These tools enable bandwidth management and control for individual VPS Hostings and provide additional security mechanisms for VPS Hostings running on the same host.
Other benefits of Virtuozzo:
* Integration with SWsoft’s Plesk control panel solution.
* Discounts on Plesk licenses.
* Name-based hosting (no need for public IP for each VPS Hosting).
* Easy to use installation utility.

Server virtualization

In Server virtualization server resources are masked & a number of operating systems runs on single operating system. All servers are treated as single resources in a network.
A software application is used is used to divide one physical server into multiple servers (virtual enviroment). The servers running in the virtual enviroment are also called as VPS Hosting - Virtual Private Servers .
Server Virtualization helps to strengthen infrastructure, optimize utilization, reduce total costs and improve business legerity. With server virtualization, multiple operating systems and software batches can be consolidated on a single processor-based platform, and platform resources can be dynamically allocated to meet specific business and application requirements.
Todays Server Virtualization softwares supports number of features which makes it easy. The server virtualization softwares improves security, lustiness & ability. It helps to booste server performance & capacitwith a good server uptime.

Automation of Backups in Virtuozzo (Windows)

The virtual environments (VE’s) within Virtuozzo can be integrated with the Windows Scheduler to have automated backups performed.
By creating a simple batch file and integrating it with our Command Line Interface (CLI), the process can run at regular intervals on the server. Both full and incremental backups can be performed through the Windows Scheduler. The command used to backup a VE is called vzbackup. Examples of how to perform each type of backup is listed below.

While running this command, vzbackup does the following:

It connects via SSH to the Source Node where the identified VE you wish to back up resides;


It compresses the private area of the selected VE and its registry settings to a .zip formatted file;


It connects via SSH to the Backup Node


It transfers the compressed file to a special backup folder on the Backup Node


For example, to back up a single VPS Hosting (101) hosted on a Hardware Node, the command below would back it up on that server.
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vzbackup 101
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To have the scripted backup create a backup on Host Node (10.10.40.100) and send it to the Backup Node (10.10.40.200), the following command would be used:
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vzbackup 101 -A 10.10.40.200 –U Administrator –P passwd200
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Where

-U is the Administrator login to the backup node. This option can be omitted – in this case vzagent0 password should be used with the –P option.
-P is the password of the Administrator ID to the specified server
-A is the IP address of the Backup Node to receive the backup

Note: In case you have the Service VPS Hosting in the NAT mode you have to use the Node IP with –A option. In case you have Service VPS Hosting without the NAT mode, you will use the Service VPS Hosting IP with –A option.

In the example below, this backup script allows all the VE’s to be backed up at once:
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@echo off
for /F “skip=3 usebackq tokens=*� %%i in (`cmd /c “vzlist -ao veid�`) do (cmd /c “vzbackup “%%i && echo VPS Hosting ID %%i has been backed up!)
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Goodluck!