Posts Tagged ‘virtual server’
Here are the Top 12 referrers to our blog over the past 3 months, the numbers of referrals are in parentheses.
- http://pro-linux.de/berichte/ext4/ext4.html (546)
- http://dabcc.com/article.aspx?id=9653 (342)
- http://networksecuritytoolkit.org/nst/index.html (110)
- http://polishlinux.org/apps/cli/ext4-defragmentation-with-e4defrag/ (59)
- http://communities.vmware.com/thread/189804?tstart=0 (49)
- http://techblog.41concepts.com/2008/03/31/shrink-your-windows-disk-image-on-wmware-fusion-mac/ (42)
- http://blog.rightscale.com/2009/01/09/amazon-launches-ec2-console/ (37)
- http://wordpress.com/tag/vhd/ (33)
- http://wordpress.com/tag/vmdk/ (32)
- http://virtualgeek.typepad.com/virtual_geek/2009/01/updated-homebrew-esx-hardware-list.html (32)
- http://blogs.msdn.com/heaths/archive/2005/07/30/445621.aspx (32)
- http://kakku.wordpress.com/2008/06/23/virtualbox-shrink-your-vdi-images-space-occupied-disk-size/ (31)
Thank you for the referrals. Hope the content is meaningful for our readers.
The Microsoft Virtual Hard Disk (VHD) format is the common virtualization file format for
- Virtual PC (host: Windows XP or 2000, guest: multiple PC-based operating systems)
- Virtual Server (host: Windows 2003, Small Business Server or XP, guest: Windows 2003, XP, 2000 and NT4 SP6a)
- Windows Server 2008 with built-in hypervisor Hyper-V (host: Windows 2008 64-bit, 64-bit and 32-bit guests: Windows 2008, 2003, SuSe Enterprise Server 10, WIndows Vista, Windows XP)
Microsoft’s has introduced the Run IT on a Virtual Hard Disk program so that customers can try Microsoft’s and its partner’s products downloaded as a pre-configured virtual hard disk, i.e., virtual appliance, for free in their own environment , for 30, 60 or 90 days, without the need for dedicated servers or complex installations.
Windows Server 2008 VHD’s:
Pre-requisites: Microsoft Server 2008 Hyper-V must be installed on a physical machine. A 64-bit system with hardware-assisted virtualization enabled and data execution prevention (DEP) is required. You should have a clean install of x64 edition of Windows Server 2008 to be able to use the Hyper-V technology. Detailed pre-requisites are availabe here.
- Windows Server 2008 Standard Edition x86 (Full Install) VHD
- Windows Server 2008 Standard Edition x64 (Full install) VHD
- Windows Server 2008 Enterprise Edition x86 (Full Install) VHD
- Windows Server 2008 Enterprise Edition x64 (Full Install) VHD
- Windows Server 2008 Standard Edition x86 (Core Install) VHD
- Windows Server 2008 Standard Edition x64 (Core install) VHD
- Windows Server 2008 Enterprise Edition x86 (Core Install) VHD
- Windows Server 2008 Enterprise Edition x64 (Core Install) VHD
What is it used for?
Evaluate the new capabilities of Exchange Server 2007 SP1.
System Center provides you a solution for operating system deployment, patch management, software distribution, virtual application streaming and more (product homepage and Configuration Manager Techcenter)
Windows Server 2003 R2 simplifies branch server management, improves identity and access management, reduces storage management costs, provides a rich Web platform.
Office SharePoint Server 2007 is a collaboration and content management server that supports all intranet, extranet, and Web applications across an enterprise within one integrated platform.
An integrated security system that delivers comprehensive, coordinated protection across endpoints, messaging and collaboration servers, and the network edge. It simplifies management and provides critical visibility into threats, vulnerabilities, and configuration risks
System Center Essentials 2007 SP1 is a new management solution specifically designed for IT professionals working in midsize businesses troubleshooting user problems, automating management tasks, managing multiple systems, and diagnosing and resolving IT problems
None of Microsoft’s partners are offering pre-configured VHD’s on Microsoft’s site at the time of writing. I am wondering why this is so?
Top Ten Posts for Q4 2008
- Defragment Ubuntu, Fedora, ext3, ext4
- How to convert a VMWare VMDK to a Microsoft, Xen VHD
- VirtualBox – setup, share, shrink, convert
- How does shrink with vmware disk manager work?
- Virtual Machine Disk Image Compression
- Compressing Virtual Images
- rsync vm, vhd for backup, disaster recovery, ec2
- How to launch first AMI on Amazon EC2?
- Steve Herrod’s Top 10 Predictions for Virtulaization for 2009
- scp, VSS for Windows VHD backup, disaster recovery
Top Ten Search Terms for Q4 2008
- ubuntu ext4
- vhd on usb
- convert vmdk to vhd
- ext4 defrag
- amazon ec2 “virtual server” vhd
- ext3 defragmentation
- rsync vhd
- convert vdi to vhd
- shrink vmdk esxi
- compress vmdk
- compress virtual image
- How to convert a big VMWare VMDK to a Hyper-V VHD?
- WinImage VMDK to VHD converter for Microsoft Virtual PC and Virtual Server
- VirtualToolkit VMDK to VHD converter for Xen
- VHD to VMDK: There does not seem to be a demand for this.
Experience with running out of storage
Background about sparse files, Windows NTFS and VHD
- NTFS Compression, sparse files and operations on them
- UNIX sparse files
- Be Careful with VHDs and Windows XP Compressed Folders
- Why do VHD’s grow?
- What is a VHD file, what is a disk image?
VHD Pre-Compactor & Compactor
When you create a new VM you can pre-allocate all the storage in one shot or let the storage grow on demand. In the latter case, the VM uses a sparse file
- Compact your Microsoft Virtual PC 2004 VHD Files
- Compressing Microsoft Virtual Server 2005 VHD files
- Virtualization with Microsoft Virtual Server 2005 by Roger Dittner, David Rule, Jr., Ken Majors
- How to compress Microsoft Virtual PC 2007 hard disks
- Compressing Microsoft Virtual PC 2007 Images
- Compressing Microsoft Windows Server 2008 Hyper-V disk images
VMDK Wipe & Shrink
3rd Party (Not from MSFT & VMW)
Rsync: for transferring files between machines
- IZO: Applications of Large-Window Compressions to Virtual Machine Management (Mark et al. IBM Almaden, USENIX, Nov 2008)
- CZIP [ppt][paper]
- redundancy elimination within large collections of files
- Data Domain SISL
- Hyperfactor (IBM Data Depulication)
- Network Applicance
As explained in the article on vhd pre-compactor, the pre-compactor zero’s out the unused blocks. The compactor can then collapse some of these blocks. Ideally if all the zero filled blocks are at the end of virtual image file, then the file can just be truncated. This is essentially what de-fragmentation does. It takes all the free blocks and moves them to the end of the disk as it tries to make all the blocks for the files on the disk to be contiguous.
Files are represented on disk by a sequence of blocks. The operating system maintains a list of free blocks and used blocks. When files are created by a program, the operating system takes some of the free blocks, marks them as used and attaches them to the file. Similarly when the file is deleted the blocks as part of the file are put back on the free block list.
However the deleted blocks are not zero’ed out. So consider a virtual image which at its peak had 3GB of used blocks, but since then a lot of files have been deleted and is currently using only 1GB. There are 2GB of free blocks on the system, but these blocks are not necessarily zero, they may contain the contents of some files which have been deleted.
The pre-compactor zeros out the deleted blocks. It does this by creating a large file and writing zeros to it. The operating system keeps giving it all the free blocks and the pre-compactor just zero’s them out.
Then the compact tool can collapse these zero blocks and realize some savings. Ideally one should run defrag on the disk before running the pre-compactor (see article)