Jump to content
XPEnology Community

ESXI + USB drives + Xpenology = ?


Recommended Posts



I'm currently using vmWare ESXI 6.5 on an Intel NUC and I have two 3TB USB drives attached to the NUC.


I first tried to use FreeNAS but the FreeNAS community really doesn't like the idea that I'm passing through two 3TB USB drives to FreeNAS and using it as a RAID1 with ZFS.


So my question: Is it possible to use BTRFS (with a RAID1) with USB drives which are passed through directly to a virtual XPENOLOGY?


The VMs and ESXI are installed on the internal msata ssd drive.



  • Like 1
Link to comment
Share on other sites

I don't think you can do it with a device passthrough, but you could set up ESXi to use the USB drives as datastores, then create virtual disks in the datastores, which will then be accessible by DSM under XPenology.  Also, you may be able to map the USB drive storage with physical RDM, which is able to translate a NVMe drive as a SCSI device.  It may work to translate the USB storage to SCSI as well (you'll still have to disable the USB arbitrator).


See: http://www.virten.net/2015/10/usb-devices-as-vmfs-datastore-in-vsphere-esxi-6-0/




Edited by flyride
Link to comment
Share on other sites

Sorry my post has been written before I saw that you have updated your post.


First a short question: If I'm using virtual disks on datastores and using them in XPenology with BTRFS - is it a good way?


Because I'm using then two filesystems? VMFS and BTRFS?


FreeNAS users told me that ZFS shouldn't be run like that, ZFS has to be on the baremetal disks and no layer should be between data and disk except ZFS. ZFS seems to be really critical because of RAM & disks and the latency of USB.


So virtual disks (VMFS) and BTRFS are usable? There's no problem then using it with RAID? And BTRFs doesn't have a problem with USB disks and RAID?

Edited by Datenbunker
Just have to read edit from flyride...
Link to comment
Share on other sites

If you present virtual disks to DSM, it does not know and treats like regular block storage.  The latency question is a good one but DSM seems fairly tolerant of that.  You'll just have to test it for yourself. 


That said, if you get pRDM to work, actual block storage commands are being presented to the physical media and it is essentially direct disk access with a translation for the controller only.  If I were in your shoes and had a choice, I would configure the USB drives as pRDM.


In my first response, I left you a link to my journey on ESXi, where I did what you are trying to do, but with NVMe.  Initially RAID 1 BTRFS on two VMFS volumes, then converted those to physical RDM.  Still RAID 1, still BTRFS, DSM seems happy.  Again, if latency is a problem, I do not experience it and you might, but you will have to try and report back.


Link to comment
Share on other sites

Now it's a little clearer.


ls /vmfs/devices/disks

Doesn't show the usb disks at all. The question is can I temporarly stop usbarbitrator (like seen: http://www.virten.net/2016/11/usb-devices-as-vmfs-datastore-in-vsphere-esxi-6-5/ ) to be able to see the disk information and create a virtual RDM. And after enabling usbarbitrator or after an reboot is it still possible to access the vRDM.


Have to check this.

Edited by Datenbunker
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...