VPS Hosting Stuff

Virtual private server is the technique of splitting the physical server into many virtual servers to get multiple servers. This is mainly a cost effective technique. The physical servers are really very costly. So when these can be split to many logical servers, the cost remains the same of getting a physical server. But at the same time, there are many servers available. This is mainly useful in the hosting of web sites. So the users often come up with the doubt of whether VPS is a best choice for them. It is essential to understand the scenario to answer the question.

VPS is ideal for those web developers who are technically advanced. Those who require access to the root server for their administrative purposes can go for a VPS hosting service. They aim at getting total control over the system.

Those who want a control over the resources in the server can opt VPS. The control over space and the programs necessarily requires the system to be VPS. The users can allocate the resources as per the availability when he can carry out the administration of the environment.

If you want to start a hosting company aiming at making profit in your business, then VPS is a right choice for you.

A virtual private server (VPS, also referred to as Virtual Dedicated Server or VDS) is a method of partitioning a physical server computer into multiple servers such that each has the appearance and capabilities of running on its own dedicated machine. Each virtual server can run its own full-fledged operating system, and each server can be independently rebooted.

VPS Advantages
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The main advantage of VPS is the ability of each server to execute independently. The servers run on their own OS and resources. Each server has no access to the resources or software running on any other server connected to the same physical server. So when there is any problem in the working of one of the servers, the total performance is never affected. Only the affected server needs to be halted and all others continue delivering their service.

One of the main advantages of using VPS is the reduced cost in obtaining multiple physical servers. The expense required to get multiple resources and network can be lessened as the physical server is virtually partitioned. Each server has all the functionalities of a real server but at the same time there is no need of getting the real server for use. This is mainly beneficial when the servers of architecture like mainframe are too costly to buy. There you can emulate the servers and reduce the over all expense.

Each server has its own share of CPU, memory and bandwidth. They need not compete for these resources. The end result is a high performance system capable of doing multiple tasks for any number of users. The virtual servers never get access to the resources of other virtual servers in the system, though they can access the physical server through proper access requests.

The users can install their own software in their virtual server. The update or integration of this software in no way will affect other servers in the system. Users can never look into the data existing in other servers of the system. No transparency is available to the data or resources of the servers from another server of the system. Thus privacy and security is ensured in the system.

The servers have their own operating system. This allows for their rebooting without affecting the physical or virtual servers in the system. The highly efficient control panel helps in the up gradation of software in the virtual servers.

The traffic at the physical server can be divided into the virtual servers. This helps to get rid of the issues related to the demand for resources and servers in the system. The traffic at one of the servers will never slow down the performance or execution time of another server as complete isolation is provided in the virtualized environment.

Because of these advantages of virtual private servers, they are in great demand in the business sectors. Those who are web hosting resellers use this technology to help their clients to get a server that has all the functions of the root server. This will help them to get more money at the expense of little cost from their pocket.

STEPS TO TAKE BACKUP :
You will need to install the perl Lchown module on the backup server. So on the backup server run this:

perl -MCPAN -e “install Lchown”

To add a central backup server, first go to  admin home -> central backup servers  and add the servers by providing the parameters there. The parameters are:

Backup Server Name/Ip

Slave-ID Slave ID is needed if you want the browse backup feature, that allows the end user to browse and restore his own backup files individually. To enable browse-backup, you have to add the backup-server into the hyperVM cluster, and then provide the slave-id of the backup-server here.

SSH Port :
Backup Root Directory : This is the core root directory where the backup will be stored. For instance, /mnt/backup/hypervm/ . The backup of the vps will be stored inside this directory.
Number of Backups : This is the total number of backups to be taken. The default is 3, but you can set upto 7. This many backups will be permanently stored on the backup server.

You can add many backup-servers here.

After adding the backup-servers, go to server home -> central backup config and then set the central Backup Server for this particular slave. Many slaves can share one backup server. If you want the old setup, just add one backup-server, and then set this as the backup-server for all the slaves.

To enable backup for a vps, you will need to set the central backup feature, by going to vps home -> limit and checking the enable central backup

The steps required for backup:

a) You have to create a passwordless ssh channel from the master to each backup server. This is the only ssh access you will need to configure. This can be accomplished by running the scpid.sh script that comes with hypervm.

cd /usr/local/lxlabs/hypervm/httpdocs/
//foreach backupserver
sh ../bin/common/scpid.sh root@servername

The username has to be root, since you need to replicate entire userids on the backup server.

b) Setup Osimages on each backupserver.

cd /usr/local/lxlabs/hypervm/httpdocs/

//foreach backupserver
lphp.exe ../bin/backuposimage.php –backuplocation=root@servername:/full/path/to/backup/directory/ –sshport=$sshport

The above will automaticaly setup all the Osimages from the master in the backup server. The backuplocation is a composite string of the form user@server:/full/path, where ‘full/path’ is the location on the backupserver which is going to the root directory for the backups. Please note that you have to provide full paths, since otherwise the rsnapshot program will not work. The vps backups will be taken relative to the Osimage the vps is created from.

cd /usr/local/lxlabs/hypervm/httpdocs/

lphp.exe ../bin/vpsbackup.php –newarg=true

d) Schedule it everyday in cron. Or whatever period you want the backup to happen.

The central backup flag is managed via the resource plans and also in vps home -> limit . You can enable/disable central backup for VPSes by changing them either in the limits or in the resource plans.

The –newarg=true is to distinguish the current configuration from the old one. If you don’t provide the newarg=true , the backup script will fail and send a warning message to admin.

SOURCE : lxlabs.com