ESXi 4.1 USB Controller FYI

[mudtoe]

Just an FYI, if you upgrade to ESXi 4.1, make sure that you remove and reinstall the USB controller on each of your VMs, if you had previously manually installed one under a previous version. If you don't you may find that your USB devices will only operate at USB version 1.1 speeds with the previous version of the controller. There isn't any indication in the Vsphere edit VM properties that tells you which version is installed. I just stumbled on this because I had a USB controller installed in one of my VMs so that I could use a Digi Anywhere USB hub with that VM. When I upgraded to ESXi 4.1 and tested out directly connecting a USB key to that VM I got the message that said "This device can perform faster". After I removed, saved, and then reinstalled the USB controller the problem went away.

[J1mbo]

I also found this, but unfortunately the transfer rate in the guest is not affected even so and seems to top-out at about 32Mbps in my testing:

http://blog.peacon.co.uk/usb-passthrough-with-esxi-4-1/

http://blog.peacon.co.uk

Please award points to any useful answer.

[mudtoe]

I just did a speed test with a USB hard drive and I'm getting around 35 megabits per second. That's faster than the 11 rating for USB 1.1, but as you said, not good enough to connect a USB hard drive to a VM for the purposes of backing up files. I guess the point of the USB support for this iteration of ESXi is to allow people to put things like dongles and fax modems on the on the server for the VMs to use, and not for the purpose of taking backups.

mudtoe

[SGalbincea]

How does one go about connecting a USB Hard Drive to an ESX guest? I have added the controller - now what?

[mudtoe]

You do it from the same screen where you added the USB controller. Pick "Add USB Device" and then you should be presented with a list of available USB devices on the host.

[SGalbincea]

Hmmm, I don't have that option available....is this a new feature in 4.1? We are running 4.0u2 at the moment.

[mudtoe]

Yes, hence the title of the thread.

mudtoe

[Jackobli]

I just did a speed test with a USB hard drive and I'm getting around 35 megabits per second.

Megabits?

If it would be megabytes, that would be about the limit of most USB 2.0 harddisks. The controller on most external USB harddisk does not handle more and/or the protocol overhead is serious. That's why 400 MBit Firewire mostly tops 480 MBit USB and thats why USB 3.0 has been invented.

[mudtoe]

I'm afraid it's 35 megabits (between 4 and 5 megabytes per second), not megabytes. On a direct USB connection under native Windows 7 I can get about 240 megabits (30 megabytes) per second with that particular drive. The speed is pretty disappointing. As I posted earlier, I guess this version of the support is mostly for people who need to hook up slower devices, like dongles and fax modems, to the ESXi host for use by the VMs.

I've already been using a Silex SX-3000GB network USB hub for that purpose, and it's equally slow (I was hoping that this new ESXi USB support would be much faster, as I already had the functionality with the 3000GB, just not the speed), although it's got one advantage over the Digi Anywhere USB device in that you can plug a hub into it and share the devices across different VMs at the same time, whereas the Digi device can only be assigned to one VM at a time, and all the USB devices attached to it are automatically assigned to only that one VM.

I'll have to run a couple of speed tests on my copy of Workstation 7 to see if it's USB support is faster.

mudtoe

[tranquilnet]

RE: USB 3.0 and ESXi 4.1

1) Does any one know if USB 3.0 is supported in ESXi 4.1 and if the actual throughput is anywhere close to 5GB/s?

2) What is the fastest external device that you would recommend to attach to an ESXi 4.1 host to backup/replicate data on for rotating offsite?

Thanks for your thoughts in advanced.

-Will

www.tranquilnet.com

[mudtoe]

I don't have any equipment with USB 3.0 on it (I wasn't aware that USB 3.0 was even common yet) so I can't speak to that. However, as indicated earlier in this thread, the USB 2.0 speeds are not suitable for attaching a USB 2.0 hard drive to a VM for the purpose of taking a backup. From my testing USB hard drive performance is only 15-20% as fast under ESXi as it is when connected directly to a computer not running VMWare. That's not fast enough to be practical to use as a backup device, unless the quantity of data being backed up is small. As far as I know there is still no good solution to connect a USB hard drive to a VM under ESXi for the purpose of taking a backup. I've tried Digi AnywhereUSB, Belkin, and Silex 3000GB. All work, but all have the speed issue. Your best bet, if you want to run the backup from within the VM, rather than just backing up the vmdk files from ESXi itself, is to connect the USB drive to a seperate computer, set it up as a network share, and then run the backup to the network share on that computer from the VM.

mudtoe

[tranquilnet]

I appreciate your quick reply. So it seems that USB is a no go" if speed is a concern. Understood and duly noted.

I will definitly consider backing up to a network share off of a traditional non-VM server with a USB 3.0 device attached.

What do you think about a pci-e attached SATA or Firewire solution?

Firewire

SATA

Thanks!

[DSTAVERT]

Even if it were possible anything directly attached to the Host that is removed can destabilize the host. Also adding would most likely require a restart.

[Jackobli]

1) Does any one know if USB 3.0 is supported in ESXi 4.1 and if the actual throughput is anywhere close to 5GB/s?

First: Thou shall not occupy other people's threads. Instead open a new one. The chance of an answer will be bigger too!

As mudtoe wrote, USB is not the first choice.

Do you really expect 5 GB/s (GByte)? Or Gb (Gbit)?

2) What is the fastest external device that you would recommend to attach to an ESXi 4.1 host to backup/replicate data on for rotating offsite?

Perhaps LTO5? Should give you a uncompressed datarate of 140 MByte/s and a uncompressed capacity of 1.5 TByte. It's robust and the media-costs should be affordable.

Else, you may choose a portable NAS (QNAP, Iomega etc.) or something like this Areca external RAID bay.

[tranquilnet]

I created a new post for my question. I apologize for any confusion or "worse" practices in discussion posting ... I am a newbie and learning

http://communities.vmware.com/message/1583684#1583684

Thanks for the guidance.