Leostream
High Availability Controller
Backup and Failover-Powered by Virtualization
Leostream High Availability (HA) Controller automates the backup and restoration of both running and stopped Virtual Machines (VM). You can store images on local vmfs partitions, or remote NFS and Windows shares as a backup set.
You can modify VMs during restoration by giving them a new Virtual Machine Name, Windows Machine Name, and Domain.
Backup of Physical Machines
In concert with the separate Leostream P>V 2.0 physical to virtual converter you can schedule an automatic conversion of a physical machine to a VM without the need to reboot the physical machine. Once in a VM format the image can be almost instantly verified - then backed up.
Support for Traditional Backup Systems
You can move VM disk images to off-line storage without the loss of VM metadata. This means that when you restore them to the intermediate storage system they will be recognized by the Controller and can be fully restored as required.
Failover for Virtual Machines
You can protect against failure of a host server by automatically restarting affected VMs on another host.
Physical to Virtual Failover
The Controller monitors your physical machines. If one fails to respond to a network test, such as ping, then the corresponding VM can be started automatically.
Role and Policy-Based Access Control
Web-based access to the Controller means that there is no need for client software. Leostream's policy-based access control extends existing authentication systems, such as LDAP or Microsoft's Active Directory, to enable fine-grained access control of both management functionality and VMs.
Performance Monitoring and Reporting
The Controller provides real-time monitoring and reporting of host and VM information. You can choose to receive alerts by email or via SNMP.
Functionality Explained
Hot backup of ESX based Virtual Machines
According to a schedule specified by you, the Leostream HA Controller automatically takes a snapshot of the disk image of a running or stopped VM, compresses it, and stores it on a locally-attached VMFS partition, or on a remote NFS or Windows share.
A disk snapshot is taken by putting the virtual disk into read-only mode, and caching further disk writes in a REDO log. The disk image is then copied and compressed as it is written to the storage system, along with a manifest file that contains the VM's meta-data.
After the disk image has been copied the cached disk writes are applied using an iterative write process that ensures that the virtual disk cache is not filled up faster than it can be written back to the disk image. Once the cache has been emptied it is removed and the disk returned to its non caching mode.
Each VM has a backup set that allows point in time recovery, along with automated recycling of images in a backup set.
The VM can either be restored exactly as it was backed up, with information such as the origin host stored in as meta-data, or it can be modified (given a new Virtual Machine Name, Windows Machine Name, Domain) so as to create a new VM.
Backup of Physical Machines
VMs make an ideal complement to traditional backup because the images can be verified and restored very rapidly to any hardware.
Leostream P>V 2.0 provides an automated and scheduled conversion process from physical to virtual, while the Controller provides a common way of managing the converted images, and if necessary archive them into a traditional backup system.
Support for Traditional Backup Systems
The Leostream High Availability system is designed to extend existing backup systems rather than replace them. Traditional backup agents running inside a VM are still required for active databases.
A manifest file that contains all the VM metadata is stored in the Controller alongside the virtual disk images. This means that the backup images can be moved from the local disk into a backup system, and then restored if required, without the loss of VM-specific information.
There are three clear advantages of this approach over an existing backup solution: the immediate validation of a backup image (by starting the VM); rapid restoration; and the ability to restore the image to different physical hardware.
Failover for Virtual Machines
If a host server fails then all the VMs running on that host are affected. The Controller provides a rapid response to host server failures by automatically restoring the affected VMs to their previous state on another host.
The Controller achieves this by monitoring host servers continuously. If one fails to respond to a preset number of pings, then the VMs running on it are also checked before initiating failover.
During failover a suitable destination host server is identified, the cached configuration files for the affected VMs are copied to the new host server, the relevant VM disk images are remapped to the new VM location, and the VMs are returned to their status prior to failure.
Physical to Virtual Failover
Using the Leostream P>V 2.0 it is possible to schedule an automated conversion from a physical to virtual machine.
Once the Controller has control over the VM then it can monitor the physical machine using a variety of network-based health tests. If the physical machine fails the Controller will automatically start the corresponding VM.
Role and Policy-Based Access Control
The Controller provides policy-based access control to the VMs themselves (according to their categorization), and role-based access control to the Controller functionality.
A variety of roles and policies are defined within the Controller which determine the access rights of users assigned to them.
The actual mapping of users to a particular role and policy can be determined by that user's profile in an external authentication server such as Microsoft's Active Directory.
For example, you might give the Finance department's backup admin the right to back up all finance department machines, but no right to create new VMs, and no right to see the HR department's machines.
Performance Monitoring And Reporting
The Controller monitors and stores the vital statistics of each host and VM. High level variables such as memory and processor usage are shown on a "dash board gauge" while allowing the user to drill down to graphs that show usage over time.
All stored data can be exported in real-time to Microsoft Excel , SQL databases, or third party charge-back systems - enabling the creation of complex reports and real-time graphs.
Interfaces
The Controller provides external interfaces for: Microsoft Active Directory, LDAP, XML-RPC control API, Controller logging, IBM Autonomic Computing, Web query and SNMP.
Components
The Leostream High Availability system comprises the following components:
- Leostream HA Controller: Runs as either a VM, or as a Windows application. Manages VMs running under VMware ESX, GSX for Windows, and Microsoft Virtual Server 2005 R2.
- It is compatible and complementary with VMware VirtualCenter.
- The VM version requires 1.5Gbytes of memory and 700Mbytes of hard disk space, as well as a bridged network connection.
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The Windows version requires a clean install of Windows Server 2003.
Each Controller is capable of managing up to 25,000 VMs and 2,000 host servers. The performance is determined by the number of simultaneous operations per second. A single operation could be stopping a VM or receiving one sample of performance data from a host. A VM running on a moderately loaded 4 CPU host should handle 20 to 50 operations a second. Other configurations can handle up to 250 operations a second.
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Host Agent: A Host Agent is installed on the destination host server running the virtualization software. Two versions are available:
- The Leostream Host Agent for Windows is compatible with VMware Workstation 5.x running on Windows XP (any service pack), VMware GSX 3.x and Microsoft Virtual Server 2005 R2 running on Windows Server 2003 (any service pack).
- The Leostream Host Agent for ESX is compatible with VMware ESX Server v2.5 (v3.x).
- Leostream P>V Wizard: This is a stand-alone product that works in conjunction with the Controller to provide automated physical to virtual conversions.
- It converts from Windows NT4 SP6a, 2000, XP, and 2003 to VMware Workstation, GSX, ESX, and Microsoft Virtual Server 2005 R2.
Deployment
To deploy the Leostream system, download the VirtualController either as a VM disk image, register it with the virtualization software, and start it, or simply install the Windows application.
Then install the appropriate Host Agent on each host server and set the IP address of the VirtualController. The Host Agents will auto discover all of the virtual servers and report them.