Datenbunker Posted May 4, 2018 Share #1 Posted May 4, 2018 Hi, 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. Regards 1 Quote Link to comment Share on other sites More sharing options...
flyride Posted May 4, 2018 Share #2 Posted May 4, 2018 (edited) 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/ and Edited May 4, 2018 by flyride Quote Link to comment Share on other sites More sharing options...
Datenbunker Posted May 4, 2018 Author Share #3 Posted May 4, 2018 (edited) 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 May 4, 2018 by Datenbunker Just have to read edit from flyride... Quote Link to comment Share on other sites More sharing options...
flyride Posted May 4, 2018 Share #4 Posted May 4, 2018 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. Quote Link to comment Share on other sites More sharing options...
Datenbunker Posted May 4, 2018 Author Share #5 Posted May 4, 2018 The problem is that USB disks larger than 2TB can't be mounted as datastores. So I can't create an access with RDM. Quote Link to comment Share on other sites More sharing options...
flyride Posted May 4, 2018 Share #6 Posted May 4, 2018 Are you sure that applies to physical RDM (-z vs. -r)? You don't mount the drive as a datastore at all with that method. http://www.myvmwareblog.com/2013/01/14/quick-tip-how-to-create-an-rdm-mapping-file-via-the-cli/ Quote Link to comment Share on other sites More sharing options...
Datenbunker Posted May 7, 2018 Author Share #7 Posted May 7, 2018 (edited) 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 May 7, 2018 by Datenbunker typo Quote Link to comment Share on other sites More sharing options...
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