Top 10 things you must read about VMFS and Virtual Disks
VMFS is VMware’s unique high performance file system that enables multiple hosts to read and write to the same locations concurrently. It is optimized for virtual machine I/O, uses adaptive disk block sizing and uses a unique disk file locking method to ensure that the same virtual machine is not powered on by multiple hosts at one time. When it comes to virtual machine disk files you have two options; traditional virtual disks on VMFS volumes or Raw Device Mapping to enable a virtual machine to access a SAN LUN directly for its disk file. There are many things you need to now about VMFS & RDMs including how to configure, align, size & re-size, troubleshoot and also when to choose between using VMFS or RDMs. This list consists of white papers, articles and a VMworld presentation that will help you better understand VMFS, RDMs & virtual disks.
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1
VMware Virtual Machine File System: Technical Overview and Best Practices
http://www.vmware.com/pdf/vmfs-best-practices-wp.pdf
A white paper from VMware that gives a technology overview of VMFS, including a discussion of features and their benefits. It also provides best practices and architectural considerations for deployment of VMFS.
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2
Recommendations for Aligning VMFS Partitions
http://www.vmware.com/pdf/esx3_partition_align.pdf
A white paper from VMware that lists a summary of performance testing results, recommendations for VMware VMFS partition alignment, and the steps needed to create aligned VMware VMFS partitions.
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3
Advanced VMFS Configuration and Troubleshooting
http://www.vmworld.com/mylearn?classID=11674
A VMworld 2007 presentation (free registration required) that covers technical information on VMFS volumes, backing up metadata, SCSI reservations, partition alignment and more.
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4
ESX Server Raw Device Mapping
http://www.vmware.com/pdf/esx25_rawdevicemapping.pdf
A white paper from VMware that covers what RDMs are, when to use them and when not to, how to manage RDMs and technical information on RDMs.
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5
Performance Characteristics of VMFS and RDM using a SAN
http://www.vmware.com/files/pdf/performance_char_vmfs_rdm.pdf
A white paper from VMware that covers the performance differences between using VMFS datasources for virtual disks and Raw Device Mappings. It describes an overview of the technologies, the test environment used, performance results and conclusions.
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6
VMware Virtual Disks - Virtual Disk Format 1.1
http://www.vmware.com/app/vmdk/?src=vmdk
A white paper from VMware that provides a high-level introduction to the layout of the files that make up a VMware virtual disk and drills down into the details of the data structures inside the virtual disk files.
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7
A Few Technical Threads - Part 1: RDMs
http://virtualgeek.typepad.com/virtual_geek/2008/08/a-few-technical.html
A good technical blog post from Chad Sakac of EMC that covers what features work when using RDMs and what don’t and when to use RDMs.
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8
A Few Technical Threads - Part 2: VMFS Resignaturing
http://virtualgeek.typepad.com/virtual_geek/2008/08/a-few-technic-1.html
A good technical blog post from Chad Sakac of EMC that covers why VMFS volumes get resignatured and tips to avoid resignaturing.
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9
Using VMware Converter to resize virtual disk files (Pt. 1)
http://searchvmware.techtarget.com/tip/0,289483,sid179_gci1322236,00.html
A blog post that covers methods for resizing virtual disk files including use Converter, the VI Client and vmkfstools
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10
Increasing virtual disk partition size using DISKPART or GpartEd (Pt. 2)
http://searchvmware.techtarget.com/tip/0,289483,sid179_gci1324177,00.html
A blog post that covers methods for increasing the size of existing disk partitions once a virtual disk has been increased in size using Windows tools and Gnome Partition Editor.
