Comments on: Take the time to learn direct disk access to a virtual machine http://itknowledgeexchange.techtarget.com/server-virtualization/take-the-time-to-learn-direct-disk-access-to-a-virtual-machine/ A SearchServerVirtualization.com blog Sat, 28 Nov 2009 05:09:57 +0000 http://wordpress.org/?v=2.6.2 By: Rick Vanover http://itknowledgeexchange.techtarget.com/server-virtualization/take-the-time-to-learn-direct-disk-access-to-a-virtual-machine/#comment-1529 Rick Vanover Tue, 28 Oct 2008 17:18:31 +0000 http://servervirtualization.blogs.techtarget.com/2008/10/03/take-the-time-to-learn-direct-disk-access-to-a-virtual-machine/#comment-1529 Coobox - I would test the configuration with a different LUN. I just did something similar for a Windows MS SQL Server cluster, if you do this - you'll need to either remove cluster service before the swing - or get to reset the drive signatures so that the Windows drives are visible to the guest OS. As for having two VM's hit the same LUN - you could not do that unless the clustering service would manage it for Windows systems. Coobox - I would test the configuration with a different LUN.

I just did something similar for a Windows MS SQL Server cluster, if you do this - you’ll need to either remove cluster service before the swing - or get to reset the drive signatures so that the Windows drives are visible to the guest OS.

As for having two VM’s hit the same LUN - you could not do that unless the clustering service would manage it for Windows systems.

]]> By: coobox http://itknowledgeexchange.techtarget.com/server-virtualization/take-the-time-to-learn-direct-disk-access-to-a-virtual-machine/#comment-1530 coobox Fri, 24 Oct 2008 13:04:42 +0000 http://servervirtualization.blogs.techtarget.com/2008/10/03/take-the-time-to-learn-direct-disk-access-to-a-virtual-machine/#comment-1530 Can I mount the same physical hdd to two virtual machines? I need it for a MySQL cluster. pls help me Can I mount the same physical hdd to two virtual machines?
I need it for a MySQL cluster. pls help me

]]> By: Scott http://itknowledgeexchange.techtarget.com/server-virtualization/take-the-time-to-learn-direct-disk-access-to-a-virtual-machine/#comment-1528 Scott Sun, 05 Oct 2008 21:42:25 +0000 http://servervirtualization.blogs.techtarget.com/2008/10/03/take-the-time-to-learn-direct-disk-access-to-a-virtual-machine/#comment-1528 If you attached the raw LUN in virtual compatibility mode (which you should in most cases) then you still get HA & VMotion as long as the LUN is presented to all hosts. You can also use snapshots (but don't try storage vmotion unless you want your disk converted to a VMDK). The only downside to raw LUNs in virtual compatibility mode is that you need a 1:1 ratio of disks to LUNs whereas VMFS3 LUNs can have a many:1 ratio of disks to LUNs. If you attached the raw LUN in virtual compatibility mode (which you should in most cases) then you still get HA & VMotion as long as the LUN is presented to all hosts. You can also use snapshots (but don’t try storage vmotion unless you want your disk converted to a VMDK).
The only downside to raw LUNs in virtual compatibility mode is that you need a 1:1 ratio of disks to LUNs whereas VMFS3 LUNs can have a many:1 ratio of disks to LUNs.

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