Tuesday, November 16, 2010

Testing to see if aligned partitions on ESX - an Introduction

I have been looking at documents that detail speed improvements with ESX where the partitions are aligned.  These documents detail and only deal with SAN paritions:


Now I don't have access to a SAN but wanted to develop and test this with my Direct Attached Storage (DAS) for my ESXi host.  Here is the configuration of my ESX host:

Hypervisor OS: ESXi 4.0 Releasebuild 294855
Systemboard: Intel S5000PSL
SCSI Controller: IBM ServeRaid 6M - 128 MB cache
RAID for Testing:  RAID5 built with 5 73GB 10K U320 disks.
RAID Stripe Size: 64KB

To do the testing I created two Windows 2003 guests with the following configurations:

OS: Windows 2003 Standard
Service Pack: SP2
Hotfixes:  All hotfixes presented over Windows update as of 11/15/2010
Virtual Disk: 12 GB dynamic
Virtual Memory: 512MB
NTFS Format: default (4K)

The only difference is that for SERVERB, the disk was aligned to 64K as described in the documents, and SERVERA had no alignment.

I then tested the servers using iozone.org version 3.53.  In order to isolate each server I rebooted the ESX host, then gave it 5 minutes to settle, and started up the Guest target alone with no other guests running with another 5 minutes of settle time before starting the testing.

The tests were done three times for each server and the results were averaged.  Then the results for each aggregate server were compared as a percentage difference.

Now the big question, is it worth it.  The short answer is yes,  I saw an improvement on average of about 10 to 40% per test.  There were points where the aligned disk was slower, but if you look at the aggregate of the data there is an improvement.  I need to do some more cleanup of the data but I will be posting it soon.

Friday, October 29, 2010

Installng Zabbix appliance into Virtualbox with VMDK to VDI conversion

     OK, I know the title is a little long, but it is descriptive. Yesterday I stumbled across the Zabbix appliance and wanted to see what it could do.
     Well I am still checking out Zabbix, but I wanted to see if I could run the Zabbix appliance using VirtualBox's native disk format VDI instead of the originally provided VMDK virtual disk.

     First off adding the VMDK into VirtualBox is easy as cake

  1. Download the appliance from www.zabbix.com
  2. Extract the VMDK and VMX files.
  3. By looking at the VMX file, you notice the parameters that are pertinent to create
    1. OS: Linux
    2. Version: OpenSUSE
    3. Memory: 512MB
    4. Storage Controller: SATA
    5. Network Attached Adapter: Bridged
    6. Adapter type Intel PRO/1000 MT
  4. Copy the VMDK to where you keep your VDI files, go to the Virtual Media Manager and add the disk to the list, then attach the disk to the SATA adapter and away you go.  
    For me it started up fine the first time without any problems.
    Now for the fun part; converting the file to VDI

    Use the following command:

         vboxmanage.exe clonehd \file.vmdk zabbix.vdi --format vdi

   Now you just go to the Virtual Media Manager and attach the VDI and away you go.  The one thing that I did learn is that you need to convert the VMDK to a VDI before you start up the machine the first time.  So if you did the test with at the top of the article, just delete it and pull a new copy of the VMDK from the archive you download.

Thursday, August 19, 2010

Success in improving RAID speeds

After a long and hard trial process, I have increased the speed of my RAID5 array on an IBM ServeRAID-6M to a very acceptable level

Before I worked on this, guests on a 5 disk RAID5 were getting 5MB/s and after-wards I am getting the following Speeds

  • Windows 2003, 12GB, Read tests with HD_speed are 92 MB/s
  • Ubuntu 9.04 server, 8GB Read+Write tests, using dd are 32 MB/s
My second RAID was only 3 disks because I had a problem with 2 of the disks. Here are my suggestions for building a RAID5 from used parts

  • Test the READ and WRITE speeds of each disk by itself. I had 1 U320 disk that was reading fine at 60 MB/s but crippled down and would only write at 5 MB/s
  • Have the same interface; one disk was a U160, and it could only read at 50 MB/s
  • Do not include any disks that are considerably slower than others, it will slow down the whole array.
  • Not sure this is true with all Array controllers, but make sure that both the disks and the array are set to write back, not write through. Also the setting for the disks can only be change while they are not in an array, and cannot be change once they are built into an array
These are my preferences, and not sure they will affect anything.

  • When building the array use the largest stripe size. The ServeRAID-6M goes up to 64K
  • When formatting the VMFS Datastore choose a larger block size like 4MB or 8MB.

Tuesday, August 17, 2010

ESXi on USB - Part II

I have been working with a test version of ESX 4i, 4.0 U2 on a USB stick. I installed it the USB stick like I documented on my August 4th post. I like it but seeing some problems. For some reason it is slowing down my system. When I benchmark my ESX host it is only getting 5MB/s on disk access for the guests.

Now these guests are either on a single SCSI U320 disk attached to a ServeRaid-6M, or in a RAID 5 config on that same card, and they are behaving poorly.

I believe that somehow the ESX hypervisor is writing to the USB stick and slowing the whole system down. So I am going back to an installable version on a SCSI disk

Wednesday, August 4, 2010


I found this great little tutorial on how to install ESXi onto a USB stick. I know that there are a bunch of ways, but this was fast, simple, and can be done from windows with tools that I already have: WinRAR and WinImage


Give it a shot.

UPDATE: I use this on a dedicated system so I am not concerned with data loss, but from my tests with 4.0 U2 the hypervisor will grab a partition and format it with VMFS.

Thursday, July 29, 2010

Client Desktop Laptop Hypervisors

It looks like there is a new front for the virtual world, notebook hypervisors. There are two products out there that are touting that you can use a laptop for two images like a corporate / home product or a WinXP / Win 7 product.

No matter what you would be using it for, it looks like there is a new market out there. So far I found two products. Citrix XenClient, which is available for download, and VMware's Mobile Virtual Platform (MVP).

Just to check things out I purchased a second hardrive from my T400 in order to test it. Citrix recommends strongly for XenClient that you have an Intel vPro system, and the Lenovo T400 fits the bill. I will be trying it out and getting back to you.

Thursday, May 20, 2010

Interesting new features for VirtualBox 3.2.0

Hey, I was looking at the new VirtualBox, and it has some really new features. They are memory ballooning, memory page de-duplication, and new IO sub-system.

It looks like Sun is really upgrading this product for prime time!


Wednesday, May 19, 2010

Improving SCSI performance on ESXi Whitebox

OK, the upgrade to SCSI went well, I converted from a SATA to SCSI system.

Added the following components:
  • IBM ServeRAID 6M, PCI-X card
  • 1 36GB drive to use as boot, and ISO storage
  • 5 74GB drives in RAID5 to be used as main datastore (272 GB)
  • 1 500GB SATA drive from old ESXi Server. Source Datastore to move data onto RAID5
Now everything was going well, but was noticing that the speed performance was slow. Now I expected it to be slower with writes on RAID5, but I was expecting the reads to scream.

That was not what was happening. So I started using HD_Speed and noticed some things.

  • Read speed on SATA drives 115
  • Read Speed on SCSI RAID5 4.5
That was a big difference. So I did some digging and did the following changes to make some improvements

  • Moved the ServerRAID 6M to PCI-X slot 1 because it was 133 Mhz, Removed the other SCSI card because if there was anything in Slot 2, it downgrade to 100 Mhz and the card was only rated at 133.
  • Made sure that the Cache was on
  • Upped the queue limit from 64 to 96 into the BIOS
After I did that the Read speed moved up to 45. Not bad. One other thing that I noticed is that when you move to larger downloads like 4MB it would move up to the 100 to 200 range.

Also I could benchmark 2 servers simultaneously from the SCSI RAID5 and it did not impact each other.

Wednesday, March 31, 2010

Upgrading Home ESX host to SCSI

Curently I am upgrading my ESX host from SATA to SCSI. I am doing this for the following reasons:

  • ESXi will not recogonize SATA as RAID array.
  • While SATA is cheap, I have noticed that running 4 or 5 VM's concurrently on the same datastore that is comprised of 1 disk it will tax the datastore where I can see delays in the guest systems.
  • Noticing heavy background disk access that does not show up on the Performance Graphs for the disk. Essentally it is useless busy disk time.
  • I have this cool IBM ServeRAID 6M card I want to give a try with some SCSI disks

Now my current ESX host has a 73GB SCSI drive that is used for the boot of the ESXi OS and to store the ISO's and a 500GB sata for the storage of the Guest VMs. I plan to replace it with a 6 disk 73GB RAID 5 SCSI array and see how it performs.

Currently I have only half of the disks, and awaiting the purchase of the remaining ones from ebay to complete my conversion.

Wednesday, February 10, 2010

Getting VMware Patch Notices Automatically

Hello all.

I found this extremely interesting and surprised that no one has told you about this. VMware has a ListServ for it's patch releases. Great for getting automatic notices of vulnerabilities of your vmware products.

Here is the link to get onto the ListServ

Here is the archive of their archives:

Sign up right now

Sunday, January 31, 2010

New Widget

Added the BT-Cumulus widget so that it would be easier to see my tags

Thanks to Roy Tanck for creating this and to kayenere for the code to get it onto my page