USB HDD not showing in VMWare ESXi

[thymox]

Hi all,

Running VMWare ESXi (VMkernel 3.5.0 #1 SMP Release build-153875) on the bare metal. The machine has 1TB in a RAID 5 (so around 750GB usable storage) and 2x1TB USB HDDs (for backing up onto).

The VMWare ESXi system has had ssh enabled.

When attached, the USB HDDs are shown in /var/log/messages appropriately and fdisk shows them - one example:

Disk /dev/disks/vmhba32:0:0:0: 1000.2 GB, 1000204886016 bytes

255 heads, 63 sectors/track, 121601 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

/dev/disks/vmhba32:0:0:1 1 121601 976760001 83 Linux

However, it doesn't show up in the vmhba32 (USB Storage Controller) entry under "Storage Adapters" on the Configuration page on the VMWare Infrastructure Client tool.

So, a couple of questions - does anyone know if it is possible to get USB devices passed to a guest OS (I'm running Windows SBS2008 and Debian Lenny as guests) or how to get USB HDDs recognised so I can use them either for extra storage in a guest or to script a backup of the ESXi server?

Cheers.

Grant.

[weinstein5]

Welcome to the Forums - It is not possible to use a USB attached storage device as a datastore for ytour ESXi host or provide access to it from a virtual machine. In vSphere you will now should be able to provide access to the USB drive but in 3.5 this is not possible.

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[thymox]

Thank you for your swift response, WEinstein5.

Do you know what the reason behind this might be? Clearly the underlying Linux system on which VMWare ESXi runs knows about the disk and knows how to handle it - if it didn't, it wouldn't show up with an fdisk!

OK, regarding my second thought - essentially mounting the USB drive (which has an ext3 volume on it, by the way) somewhere and running a script to backup the guests to it (literally, just copying the files over to it - or taring them if necessary)?

[weinstein5]

ESX and ESXi are not based on Linux - the vmkernel which in essence is the Operating System of ESX/ESXi was written form the ground up by VMware does not recognize USB drives. The Service Console where you are seeing the USB device attached is a priviledged VM as it were that is based on RHEL 3.

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[thymox]

If the VMKernel does not know how to handle USB devices, how can it pass control of them over to the "privileged service console"? If the service console is based on RHEL3, how can I add extend it and add more regular Linux functionality to it?

[mehul96]

ESX and ESXi does not support USB HDDs for datastore (just like they don't support sound cards). Service console is based on RHEL so it may be able to detect but vmkernel will not support it as a datastore.

Mehul

[weinstein5]

I oversimplified the vmkernel ability to see the USB bus - it can but it is not able to utilize USB based storage - in terms of extending the use of the service console - you will not want to do that. The service console is based on a modified version of RHEL 3.5 and is used to manage your ESX host - so extending the Service Console and adding more Linux functionality can affect your control and management of your ESX host. Best practice is limit on what you install into the service console and how you use it.

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[DSTAVERT]

Wishing and wanting here won't change the fact that it doen't work. If you want external storage add a NFS capable NAS device. There are small IOMEGA devices on the hardware compatibility list.

[ad4m1]

My advise, if your still interested in using USB storage on your VMware ESXi host is to run another physical server next to your ESXi server, install your 2 USB drives on that, and then install FreeNAS (available for free from http://freenas.org/) which will support your USB drives. You then setup iSCSI on the FreeNAS box and tie this into a iSCSI datastore on your ESXi machine.

This has been tried and tested by co-workers of mine on the full licensed version of ESX, but i'm fairly sure it will also work on the free ESXi version too. I'm hoping so because i'm intending on doing something very similar myself

Hope this helps.

[Yosias]

USB is very slow! We tried this, exactly as you did. We first plugged it in to our ESXi host = no go. Then we moved it to another backup windows server, an old Sysco box that was just sitting around collecting dust. plugged the 1tb usb drive, installed (WSFU) as per document attached, then added that 1tb usb as NFS to our ESXi. Fired up the backup script to write to it. Well let me just say it would have been faster if I dismanteld the ESXi host and hand carried the files to a backup device = it was extremely slow but doable. So we opted to go with eSAta and have been very happy. What we did actually was add more disk to ESXi, raid(0), backed up to that, finished within 2 minutes, restart VMs, then another script copied it to the eSata.

USB 2.0 has a raw data rate at 480Mbps

SATA II or SATA/3Gbs doubled the speed to 300 MB/s or about 3 GB

Mbps <> MB

hope this helps

[ramasan1]

so i understand properly, can someone confirm that i can or cannot do this:

i have esxi 4 installed on my dell T310. i am running win 2008 r2 as a guest os.

i would like my W2K8 vm to recognize my external 300G usb drive.

usb controller is installed as a setting. i have rebooted my esxi server, but the windows server guest does not show the usb drive.

am i to believe that esxi does not support this?

this worked no problem on my vmware server running on windows 7.

[ad4m1]

I have not been able to do this myself so I think it's fair to say that "out of the box" ESXi 4 does NOT support USB datastores simply because there is no USB support in the VMWare kernel, and therefor will not allow you to mount a USB drive and use it within your windows virtual machine.

The Windows version of VMWare allows you to do it because it uses a USB passthru driver within the Windows environment, i believe.

One workaround is to use a physically seperate machine (just a cheap old machine will do) and install a 3rd party operating system called FreeNAS <- google it for the free download. It's opensource.

Mount your USB drive on that and use iSCSI to mount them into any of your chosen VMWare virtual machines. This is what I've done and it works quite well for my home network.

As mentioned above, USB2 is slow so don't use it in a production environment where several users will be accessing the data, but it will probably be ok in a small office or home environment.

Hope this helps.