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Data recovery software for extracting files from corrupt VMDK images

Tue, 08 Sep 2009 15:50:04 GMT

MediaHeal for Virtual Drives retrieves files from corrupted VMware virtual drive images. VMDK and VHD files and binary disks / partition dumps are supported. The extracted files are saved into a new location chosen by user.

Support for corrupt VMDK snapshot drives has been added recently.

Full description of the utility and a free demo are available at

http://www.officerecovery.com/mediaheal-for-virtual-drives/

OfficeRecovery.com

Linked Clones implementation for VMware VDI environment at UC Santa Barbara, ResNet

Wed, 17 Dec 2008 16:37:08 GMT

Description:

Motivated by heavy disk costs and slow deployment processes, scripts were developed in-house to make VDI administration easier without incurring any additional costs above that which is necessary. The outcome of these scripts is two tools whose usage will be described in this document.

Our current environment is a small installation of about twenty thinclients (and associated virtual machines) that make up our student accessible lab computers. Total storage consumption is hovering around 80 GB on a single datastore with Linked Clones distributed across 2 ESX hosts. Each VM is configured with 2 vCPUs and 1 GB of memory. At the moment, standard applications like office productivity software is being used on the production VMs. A discussion to extend the application set to include engineering and graphics design oriented software is currently underway thanks to the capabilities of HP RGS.

Update - (1/22/2009)

An issue was found with linked clones that are joined to a Windows domain. Win2k/WinXP/Win2k3 domain members change their computer account passwords every 30 days. When linked clones have been sealed in Step 7, the computer account password generated after joining the domain is saved in the snapshot. This becomes an issue on the 30th day (or 7th day in pre-Win2k machines) when the computer account password is changed and the domain controller receives the new password. Step 8 in the procedure defines that the linked clones are reverted to their state immediately after joining the domain. On the 30th day, this causes the old computer account password of the linked clone to be in effect consequently disallowing any communication between the domain controller and the linked clone.

This problem can be solved in five ways (in order of increasing work and accessibility):

Proactive Solutions:
1) Disable machine account password changes on the domain controller as per instructions from:
http://technet.microsoft.com/en-us/library/cc785826.aspx

This can be limited to just linked clone domain members by applying the necessary group policy security setting to these domain members. This is the solution we employed. Any linked clones that are "Powered On" should be "Rebooted" or "Reverted" and then subsequently "Powered On" after updating the GPO.

2) Disable machine account password changes on the master image (before link cloning) as per instructions from:
http://support.microsoft.com/kb/154501
These instructions apply to Windows 2000 and NT. Use the Windows 2000 instructions on Windows XP. This hasn't been tested. It doesn't seem as though the domain controller will override this setting but it is up to the user to find out.

3) Retire linked clones every month which will probably happen often due to image updates.

4) Delete linked clone snapshots before password update occurs on the 30th day and resnap the clones afterwards.

Reactive Solution:
5) Delete linked clone snapshots, unjoin each linked clone from the domain, rejoin each linked clone to the domain and resnap each linked clone using my-vmware-cmd.sh. This can actually be relatively quick and effortless if scripted properly.

Tools and Hardware:

ghetto-esx-linked-clones.sh
my-vmware-cmd.sh
VMware ESX 3.5u3
VMware Virtual Center 2.5u3
HP SAM (Session Allocation Manager) [VDI Connection broker]
HP RGS Sender/Receiver
HP BL460c
HP EVA4400
HP T5730 thinclients

Implementation:

Step 1.

Create a Master VM image with Windows XP Professional, install VMware Tools and all applications that will be available on the Linked Clone VMs (including SAM registration and RGS Sender services). Ensure that the Master VM is set to automatically obtain an IP address via DHCP and that it is on the correct network that linked clones will be operating on.

Step 2.

Shutdown Master VM image.

Step 3.

Create Linked Clones using ghetto-esx-linked-clones.sh.

Step 4.

Create DHCP reservations on Windows DHCP server from the MAC address file that "ghetto-esx(i)-linked-clones.sh" creates using a custom .vbs DHCP IP reservation script.

Step 5.

Power on all newly created Linked Clones using VIClient if resources allow it.

Step 6.

Once powered on, a custom .vbs script utilizing WMI calls to request that the new Linked Clones join our Active Directory domain is executed from a Windows machine.

Step 7.

Once all VMs have been joined to the domain, the snap function of my-vmware-cmd.sh is run on these VMs. This is required to capture the pristine state of the system right after joining the domain.

Step 8.

At this point, the VMs are ready to be utilized by the available thinclients that have the HP SAM client installed on them. Changes that are made to the Linked Clones by users are discarded because the Linked Clones are refreshed every night using the revert function of my-vmware-cmd.sh that is scheduled with a crontab.

Step 9.

When an image needs to be rebuilt/upgraded, the Master VM image is cloned and worked on while the existing Linked Clones are online. Steps 1 through 7 are followed again on the new Master VM image and new Linked Clones are created with special attention towards disabling these new Linked Clones inside HP SAM.

Step 10.

The old inactive Linked Clones are disabled in HP SAM with old active Linked Clones left alone. The new Linked Clones are then enabled inside HP SAM. The old active Linked Clones will be manually disabled once the user logs out.

Step 11.

The purge function of my-vmware-cmd.sh is then used to destroy the old Linked Clones and all old Linked Clones are removed from HP SAM resources.

Note: With the advent of the new HP RGS licensing model, HP hardware is no longer necessary in a VMware VDI environment utilizing this display protocol.

ESX VM backup using Arcserve vmware agent after upgrade to VCB 1.5

Tue, 21 Oct 2008 08:41:59 GMT

It appears that the Arcserve vmware client agent is no longer able to mount the ESX VM's after upgrading to VCB 1.5.

Also VCBUI.exe (a tool provided by the Arcserve vmware client agent) is not able to mount and add VM's to the Arcserve database.

Nevertheless, VCBmounter runs fine on it's own, so it probably had something to do with communication between Arcserve and VCB.

The content of ca\arcserve backup client agent for windows\checkVCBInstallation.wsf brought me the solution. This file checks if VCB is installed on the local machine (our backupserver)... but when I clicked it, the script told me: "VCB Not Installed".

What do you mean not installed? VCB is located in c:\Program Files\VMWare\VMWare Consolidated Backup Framework... so why do I get this message?

Digging deeper in the script, I found that it looks for a registry key that has a DisplayName = "VMWare Consolidated Backup Framework" below HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall\

Below this key, the script looks to the InstallLocation value to see where VCB is installed... and this appeared to be empty. Was it made empty after the upgrade to VCB 1.5?

Just filled in the correct installation path of VCB, and our VM backup works perfect again.

Serial Port Mapper

Tue, 26 Aug 2008 12:02:48 GMT

Serial Port Mapper allows to map any serial port to any new port name. In other words, it allows to create aliases for serial ports. E.g.you install additional serial port expansion card to computer as COM 5 serial port. But your favourite software can work with COM1...COM4 ports only and cannot be reconfigured to work with COM5. To resolve this problem you need to map COM 5 port to COM 1 port. As a result your software can open COM 1 port but actually work with COM 5 port. Serial Port Mapper functionality can be easily integrated into your application. So you can map and swap serial ports from your application directly.

How to configure Virtual Manager on ESX 3.5.doc

Mon, 30 Jun 2008 12:54:49 GMT

Enabling and Sharing USB devices over an IP network in a VMware virtual environment

Tue, 29 Apr 2008 22:18:37 GMT

Virtual Centre server recovery

Thu, 04 Oct 2007 11:33:28 GMT

Microsoft Windows 2008 failover cluster with iSCSI

Thu, 27 Sep 2007 05:26:43 GMT

Aim : To form a 2-node active/passive cluster on Microsoft Windows 2008 guests with iSCSI disks on top of VMware ESX Server.

Procedure : I am assuming that the reader is well versed with Microsoft Windows 2003 Clustering and software-only iSCSI technology. If that is not the case then I would like to request reader, please first understand that and follow the procedure mentioned over here.

1. Three types of disks are supported in Microsoft Windows 2008 failover clustering : serially attached SCSI disks (SAS), iSCSI & FC HBA. We are looking at software-only iSCSI disks inside the guests. In order to achieve this we need to first deploy a VM which will act as a iSCSI target appliance. Configure this VM with multiple virtual SCSI disks (one disk for OS and others to share with guests as iSCSI ove LAN, better to use different SCSI controllers). Install Microsoft Windows 2003 SP1 and then install iSCSI target software (e.g. StarWind iSCSI Target http://www.rocketdivision.com/wind.html). Open iSCSI management console which gets installed as a part of target software and add devices. Add devices is a simple wizard which will create image file out of SCSI disk. This is getting hosted with iSCSI over IP on a default port 3260. Add all the locally attached SCSI disks using add devices wizard. You are done with hosting iSCSI target appliance.

2. To attach, configure and access above iSCSI disks in guest VMs (used for clustering), you need to have iSCSI Initiator software installed and configured. Microsoft provided the same as a part of operating system in their windows 2008. Configure IP or IPs in iSCSI Initiator in both the VMs to talk to above configured iSCSI target appliance. This is also a simple configuration wehre in you are suppose to provide the IP or IPs of iSCSI target applinece and discover the path or paths to disks. Please ensure that the sharing of disks configured correctly and the disks are available even after rebooting of VMs.

3. You can now follow Micorosoft Windows 2008 failover clustering setp-by-step instructions. Validation configuration wizard gives two warnings for Microsoft signed drivers used in VMs against display and mouse. Rest all the tests gets passed successfully which is in-turn a green signal to go ahead and form the cluster.

All the best guys...!