1 .How does VaaS compare to the ITSC iHost service?

The iHost Service is a shared web hosting service. ITSC will keep offering the service free.

All users of the iHost Service share the same list of software, e.g. Apache 2.1 and PHP 4.2, pre-installed on the system and the software cannot be changed easily. In addition, resources like CPU time and memory are equally shared by all users.

VaaS, on the other hand, provides flexibility and choices. User has full control of a rented virtual server and is free to install any software. More resources can be purchased as demand increases.

2. Can I import/migrate an existing phyical / virtual server into VaaS?

Yes, we support migrating servers into our system. User may do this in one of the two ways below,

  1. Online Migration
    • You are required to provide us an administrator account on the server. We'll coordinate with you to clone your server to our system. During the process, service on the server may need to be suspended to ensure data integrity. Depending on the volume of data on the server, service interruption may last for a couple of hours.
  2. Server Image Upload
    • You prepare a server image file using tools like VMware Player and upload it to our secure server. We will help to put it up on our system. At the moment, we support only the OVF/VMDK virtual image format.
3. Does a virtual server offer the same speed and performance as a physical server?

All virtual servers offered through VaaS run on state-of-art physical servers and backed by fast SAN disk storage. This ensures supreme performance of the system. There is also continuous monitoring system in place to verify each virtual server meets its performance requirements.

Backup, Restore and Recovery

1. Does backup affect server performance?

As the backup operation is independent of the server to be backup except during snapshot creation. There is basically no performance degrade during backup.

2. Is there any backup service for VaaS virtual server?

All virtual servers come with free daily backup.

3. If a virtual server failed to boot up, can I restore the system from backups?

Yes. Please call ITSC Helpdesk for help. You may choose to restore from any existing backups.

4. How long are backups kept for?

We keep the latest 7 daily, 4 weekly and 3 monthly backups.

5. Does backup of database supported?

VaaS backup is disk-based but user can ensure database consistent backup by using custom quiescing scripts. It requires VMware Tools installed and running on the virtual server.


Below are some scripting samples,

  1. Back up MySQL on Linux without stopping services or dumping the database
  2. Running custom quiescing scripts inside Windows virtual machine with ESX 3.5 Update 2 and later (1006671)

To verify custom scripts, create a snapshot manually and make sure to,

  1. Check the option "Quiesce guest file system"
  2. Uncheck the option "Snapshot the virtual machine's memory"
6. When do server backups take place? Can I request for an alternate schedule?

Backups are done daily between 9:00pm and 7:00am the next day. The schedule cannot be changed.

7. Can I access to files in the backups of my virtual server?

Files in backups of a server can be accessed from the same server using the VDR File Level Restore Client software on supported server plaforms. These include most Windows servers and many Linux distributions.

The file restoration software is pre-installed in all virtual servers offered by ITSC. The latest version can be downloaded from the following links: (Linux Windows). 

8. Does backup support files that are "in Use" or "Locked"?

Backup is disk-based so files being in use will be backup as well. But data haven't been written to disk will get lost.

Backup supports Volume Shadow Copy on Windows and Sync on Linux system. Applications that support these technologies will be notified and given chance to purge data in memory to disk before backup snapshot is created.

9. Which backups are kept as weekly or monthly backups?

The backups between Friday night and Saturday morning are chosen as weekly backups. Monthly backups are those done between the last night of a month and the first morning of the following month.

For example, the weekly backup for the week starting 4 Mar, 2012 was taken between 9:00pm, 9 Mar and 7:00am, 10 Mar. The monthly backup of Mar 2012 was taken between 9:00pm, 31 Mar and 7:00am, 1 Apr.

10. Could server backup fail? What will be the arrangement should it happen?

Backup failure could happen if a virtual server is very busy through out the whole backup period such that the system cannot take a snapshot of the server.

In case of a server backup failed, we will inform the registered server administrators by email and re-schedule the backup about noon the following day. Server administrators may contact us if they have other preferences on the re-scheduled backup.

11. How virtual servers are backup?

Backup is disk-based and is done using snapshot technology.

The backup software first creates a point-in-time image of the virtual server's file system called snapshot which takes a very short time to generate. The backup of the snapshot is then taken from a backup server connected to the point-in-time disk image over a separated storage network. This guarantees minimal impact on the server to be backup.


1. Is my data on virtual server secure?

All virtual servers and data reside on redundant storage with daily backup. Upon termination of service, the server disks, together with its backups, will be erased within 7 days.

Virtual Server Management

1. How can I access to my virtual server?

For Linux server, user may use any SSH client software to connect to it. For Windows Server, please use Remote Desktop Connection.

2. How can I read the content of a CDROM/DVD image from my virtual server?

You may mount a ISO image as a virtual CDROM drive on your desktop computer and then use file-sharing to share it with the virtual server.

On Linux, you may use the loop device.

3. Can I access to the console of my virtual server?

Yes, you may access to the console of your virtual server remotely through the VaaS Gateway. For details, please check out the ITSC VaaS Quick Start Guide.

4. How can I read a CDROM/DVD from my virtual server?

The simplest way is to load the disc into a desktop computer and share it. You may then read the content of the disc from the virtual server by mounting the file share.

5. How can I power up my server after shutdown ?

User may first connect to the console of the powered-off virtual server. Then, select "Power" -> "Power On".

6. Can I access to performance data of my virtual server?

Yes, real-time performance data can be read from the web management interface. Historical data requires the VMware vSphere Client utility.