Monthly Archives: December 2012

VT-d Verification on ASRock Z77 Pro4-M

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Strike while the iron is hot

I’m building a workstation for a friend and he chose a ASRock Z77 Pro4-M motherboard. I have had all the parts for a week and it wasn’t until today it struck me that there are some Z77 motherboards that support VT-d. There have been some conflicting information on whether or not VT-d is supported in the Z77 chipset. According to the latest information at the Intel site, VT-d is supported on Z77. However, many motherboard manufacturers have not implemented it (yet?).

Since I had the chance to test this myself I decided to try it out while I had the chance. The specifications of the workstation are as follows:

  • Motherboard: ASRock Z77 Pro4-M (specifications)
  • Processor: Intel Core i7 3770K
  • Memory: Corsair XMS 2x8GB
  • Storage: Intel SSD 520 240GB
  • PSU: beQuiet Straight Power 400W 80+ Gold
  • Case: Fractal Design Define Mini

Now you’re thinking; “this won’t turn out well with a K-processor”… Absolutely right, the Core i7 3770K does not support VT-d. After asking around I happened to find a Core i5 2400 for this test. As you can see on the Intel Ark page, VT-d is supported for that model.

Here are some shots of the ASRock mobo which is really good looking in my opinion.

pci_express

socket_area

io_ports

Let’s hook it up and see if we can get some DirectPath I/O device passthrough going.

There are two settings for virtualization in the BIOS. One (VT-x) is found under CPU configuration and the other (VT-d) is found under Northbridge configuration. ESXi 5.1 installs just fine to a USB stick and detects the onboard NIC, which by the way is a Realtek 8168. An Intel NIC would have been preferred. Once ESXi is installed we can connect to it with the vSphere client and see that we can enable DirectPath.

directpathIO

Unfortunately, I didn’t have any other PCI-Express card available to make a more extensive test. The device I have selected, which vSphere fails to detect, is the ASMedia SATA controller. This controller is used for one internal SATA port and either one internal or the E-SATA port on the back I/O panel.

Create a Virtual Machine, change all settings for it and save the changes. Launch the settings again and Add the PCI device:

add_PCI

add_PCI_choose

Once the PCI device is connected, some settings are not possible to change anymore. It is possible to remove the PCI device, change the settings and re-add the PCI device. Also, adding the PCI device and changing settings at the same time might throw some error messages.

I choose to fire up an Ubuntu 12.04 Live CD just to see if it works. Here is what the controller looks like. I hooked up an old spare drive to the ASMedia controller and as we can see it is correctly detected.

asm_controller

This was a really quick test but I will definitely give ASRock boards another try for upcoming build. Please, ASRock, send me your Z77 Extreme11 board for evaluation. Z77 with LSI onboard SATA is a real killer!

To summarize my short experience with this board:

  • VT-d on Z77 is working!
  • non-K CPU overclocking
  • 3x PCI-Express 16x ports for add in cards.
  • Power ON-to-boot is really quick
  • Realtek NIC is a slight negative. Intel would have been better.

SATA hotswap drive in mdadm RAID array

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I needed to replace a SATA drive in a mdadm RAID1 array and I figured I could try to do a hot swap. Before the step-by-step guide, this is how the system is set up for an orientation.

  • 2x1TB physical disks; /dev/sdb and /dev/sdc
  • Each drive contains one single partition; /dev/sdb1 and /dev/sdc1 respectively
  • /dev/sdb1 and /dev/sdc1 together make up the /dev/md0 RAID1 array

Here is what the array looks like:

$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdb1[0] sdc1[1]
976629568 blocks super 1.2 [2/2] [UU]

In the following steps we will remove one drive from the array, remove it physically, add the new physical drive and make mdadm rebuild the array.

Important note!
Since we’re removing one of the drives in a RAID1 set we do not have any redundancy anymore. If this is critical data on the array, this is the time to make a proper backup of it. The drive I’m removing is not faulty in any way and therefor I will not take any backups.

Step-by-step guide

  1. Mark the drive as failed
    $ sudo mdadm --manage /dev/md0 --fail /dev/sdb1
  2. Remove the drive from the array
    $ sudo mdadm --manage /dev/md0 --remove /dev/sdb1
  3. View the mdadm status
    $ cat /proc/mdstat
  4. If you prefer to shut down the system for a cold swap, do it now. Before the hot swap put the drive into standby with the following command
    $ sudo hdparm -Y /dev/sdb
    Make sure you know which drive you are going to remove before issuing this command. Operations to the disk will wake up the drive again.
  5. Remove the SATA signal cable first and then the SATA power cable.
  6. Mount the new drive and connect SATA power. I let the drive spin up for 5-10 seconds before connecting the SATA signal cable. If you did a cold swap, power on the system at this point.
  7. Identify the new drive and what device name it has. In my case, the new drive was conveniently named /dev/sdb, the same as the old one.
  8. Copy the partitioning setup from the other drive in the array to the new disk.
    Make sure the order is correct, otherwise we will erase the operational drive!
    $ sfdisk -d /dev/sdc | sfdisk /dev/sdb
  9. Add the new drive to the RAID array
    $ sudo mdadm --manage /dev/md0 --add /dev/sdb1
  10. The RAID array will now be rebuilt and the progress is indicated by the
    $ cat /proc/mdstat
    output. To have a more dynamic update of the progress use the following:
    $ watch cat /proc/mdstat

When the rebuild is done the status will look something like this again:

$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdb1[2] sdc1[1]
976629568 blocks super 1.2 [2/2] [UU]

Enjoy and be careful with your data!