Volumes on dynamic disks and raw access?

[aspirin75]

Hi all,

I wanted to set up a system with some hdd's, with two 2TB drives among them in the following way:
disk 1 OS (Win7 pro)
disk 2 past-OS
disk 3 & disk 4 are the 2T drives, with one 100G mirrored partition for VM's and the rest for raw disk access.
I would like to give the raw volume/partition to an OpenIndiana (~Solaris) VM in order to make a mirrored zpool to do backups from another (OI) system.

Well, the vboxmanage internal command only sees one huge disk, and no partitions (in fact so does the diskpart, Windows' own tool...), while I can of course see my volumes in the diskmanagement tool.
Is this the expected behavior? I mean are volumes on dynamic disks not supported for raw access? Well, that would make sense now that I think about it, but still curious.

System: Core2Quad Q6600, 8GB ram, a 80GB sata disk, a 200GB pata disk and two 2T sata disks.

Thanks a lot!

[mpack]

Raw access is an experts-only feature, so I don't normally answer questions about it. Inexpert use can result in your the entire host drive being trashed. Even for experts that is still a risk.

Generally you share the entire drive. If you share only a partition then that's only part of a drive and excludes the partition map and boot sectors, so how is the VM supposed to make sense of the drive contents? To make this work you have to provide an additional VMDK extent containing the missing parts. Really, if you don't understand what I'm talking about then you should probably leave well alone.

[aspirin75]

Thanks for the comment!

I have been using this feature for several years now (even on several host and guest VMs), so I think I get the general idea on how it works. I wouldn't call myself an expert though!
I haven't yet cerated/met this kind of setup that resides on a dynamic volume, hence the question.
What made me suspicious is that that Windows' own diskpart.exe reports no partitions on the drives, whereas I can see them in disk management. (and of course use them properly)
Most likely a volume manager works in the background and VBox/dispart.exe indeed sees the whole disk without conventional partitions, as they do not get the info through this extra layer(?).

As for your question: when the createrawvmdk internal command is used on partitions (in Windows at least) it creates two files: one vmdk file with the whole disk (in what partition info points to an other file), and the one with the partition info; so according to my understanding this should be correct.

[mpack]

I don't think that the partition being located on a dynamic disk is the problem. Being a partition (and not a disk) is the problem.

This is not to say that every guest OS will like dynamic disks - that obviously depends on the guest. But you haven't come to that bridge yet.

[aspirin75]

Duh, sorry for getting back this late - I was extremely busy.

So in the end I broke the mirror, reformatted the disks as basic volumes and made the (mbr) partitions. Then used the procedure to add the raw partition to vbox, and Solaris is fine ever since with those partitions.
format ->fdisk shows the whole disk under Solaris with the partitions there, and I only have touched the needed ones.
I made the slices and the zfs mirror. It is fine and and things seem to work

Anyways, thanks a lot for taking care of issue.

I most likely will copy the whole image to the other disk from the windows scheduler as that machine won't aways run. Riskier, less elegant, but that's all I can seemingly have...

[mpack]

It always bothers me that there's potential for confusion around this subject, so for the benefit of future readers I will note that "dynamic disk" is how Microsoft refers to the proprietary Windows equivalant of LVM. We're not discussing Dynamic VDIs here, and no guest OS has (or could have) a problem with those.