none
Move vhdx from IDE to SCSI

    Question

  • New adventure in the on-going battle of cleaning up behind someone who didn't know what they were doing....

    Hyper-V host HV1 has two drives, C:\ for the host OS (250GB in size) and E:\ for Hyper-V guests (~ 1.3 TB in size).  Four physical hard drives, RAID 10, one hot-swap spare physical disk.  Running Server 2012R2.  

    HV1 has a guest VM, APP1, that has 2 vhdx disks, C:\OS and E:\Data.  

    Problem: C:\OS on the APP1 server is stored in HV1's C:\Users\Public\Documents\Hyper-V\VirtualHardDisks directory.  And it is an IDE Controller hard drive in Hyper-V Manager.  

    I'd like to get that vhdx file moved to the HV1 E:\Hyper-V directory, where ALL of the rest of our Hyper-V Guest files reside.  I'd also like to change it from IDE to SCSI for some performance improvement.  

    Is this possible?  Simply shut down the guest, delete the IDE, add a SCSI, move the vhdx file, and reattach?  Anything in the guest config files I need to change?  Any "Watch out!" warnings? 

    Thank you, again, everyone for your input.

    Best,

    Jeff

    Wednesday, March 22, 2017 6:41 PM

Answers

  • Storage Live Migration can move the virtual hard disk file to any location the server can reach. Start by right-clicking the VM in Hyper-V Manager and selecting "Move". Follow the wizard.

    Generation 1 virtual machines can only boot from the virtual IDE controller. You will not be able to relocate a virtual machine's operating system drive to a virtual SCSI controller without converting the virtual machine o Generation 2 and converting the contained operating system from BIOS mode to UEFI mode. These are non-trivial operations and there is no guarantee of success. If your goal is a performance improvement, Generation 2 doesn't provide it except for a tiny increase in startup speed.

    The virtual SCSI controller does not provide superior performance to the virtual IDE controller except in some rare cases. Converting to SCSI would be for the purpose of gaining access to things like online resize operations.

    Do not perform these conversions. If that virtual machine runs constantly for the next 20 years, you will never recoup the time you invest to convert it. Just perform the storage migration and stop.


    Eric Siron
    Altaro Hyper-V Blog
    I am an independent contributor, not an Altaro employee. I accept all responsibility for the content of my posts. You accept all responsibility for any actions that you take based on the content of my posts.

    • Marked as answer by Reno316 Thursday, March 23, 2017 3:41 PM
    Wednesday, March 22, 2017 8:22 PM

All replies

  • Storage Live Migration can move the virtual hard disk file to any location the server can reach. Start by right-clicking the VM in Hyper-V Manager and selecting "Move". Follow the wizard.

    Generation 1 virtual machines can only boot from the virtual IDE controller. You will not be able to relocate a virtual machine's operating system drive to a virtual SCSI controller without converting the virtual machine o Generation 2 and converting the contained operating system from BIOS mode to UEFI mode. These are non-trivial operations and there is no guarantee of success. If your goal is a performance improvement, Generation 2 doesn't provide it except for a tiny increase in startup speed.

    The virtual SCSI controller does not provide superior performance to the virtual IDE controller except in some rare cases. Converting to SCSI would be for the purpose of gaining access to things like online resize operations.

    Do not perform these conversions. If that virtual machine runs constantly for the next 20 years, you will never recoup the time you invest to convert it. Just perform the storage migration and stop.


    Eric Siron
    Altaro Hyper-V Blog
    I am an independent contributor, not an Altaro employee. I accept all responsibility for the content of my posts. You accept all responsibility for any actions that you take based on the content of my posts.

    • Marked as answer by Reno316 Thursday, March 23, 2017 3:41 PM
    Wednesday, March 22, 2017 8:22 PM
  • There's no performance difference between IDE and SCSI, messing with that is a waste of your time. 

    If you want to improve performance, moving to SSD or having more spindles on your RAID10 is the way to go.

    Wednesday, March 22, 2017 9:16 PM
  • I wasn't aware of the Live Migration feature... That's awesome stuff, thank you, Mr. Siron.  

    Best,

    Jeff

    Thursday, March 23, 2017 3:42 PM
  • "There was an error during move operation.  Storage migration for virtual machine APP1 failed.  Failed to update VHD link in the configuration."

    Hrmmm.....

    Best,

    Jeff

    Thursday, March 23, 2017 4:40 PM
  • I haven't seen that message before. Could you start a new thread to get some better visibility on it?

    Eric Siron
    Altaro Hyper-V Blog
    I am an independent contributor, not an Altaro employee. I accept all responsibility for the content of my posts. You accept all responsibility for any actions that you take based on the content of my posts.

    Thursday, March 23, 2017 4:45 PM
  • This quest to convert to gen 2 VMs and then migrating VHDXs from the IDE to the SCSI controller may become more common as people seek to in-place upgrade their Win 2012 R2 VMs to Win 2016 which does not permit booting from an IDE controller.

    I get that the alternative is the recommended path...spin up new gen2 VM and put VHDX on SCSI controller from the get go but would be nice if Microsoft could somehow make the g1->g2 conversion and migrating IDE->SCSI conversion path a bit easier to take.

    Saturday, August 12, 2017 2:03 PM
  • Win 2016 which does not permit booting from an IDE controller.

    WS2016 has no such restriction.

    Eric Siron
    Altaro Hyper-V Blog
    I am an independent contributor, not an Altaro employee. I accept all responsibility for the content of my posts. You accept all responsibility for any actions that you take based on the content of my posts.

    Monday, August 14, 2017 2:19 AM