Category Archives: Notable KB Articles from the week by The VMguy

TheVMguy’s Notable KB articles from the week

http://vmguy.com/wordpress/index.php has posted his weekly Notable KB articles from the week

Sorry, better late than never. Here’s last week’s collection from the 71 New/Updated KB Articles:

I thought the following where wroth a extensive read.

iSCSI and Jumbo Frames configuration on ESX 3.5

KB Article
1007654

Products

VMware ESX

Product Versions

VMware ESX 3.5.x

Symptoms

Large queues are seen while monitoring Jumbo Frames

Purpose

This article provides information related to setting up an NAS and iSCSI environment with Jumbo Frames.

Caution: This is not a VMware supported configuration.

Resolution

Important Jumbo Frame Information

The following is important information to know when using Jumbo Frames:

  • Any packet larger than 1500 MTU is a Jumbo Frame. ESX 3.5 supports frames up to 9kB (9000 Bytes). They are limited to data networking only (virtual machines and the VMotion network) on ESX 3i/3.5.

  • Jumbo Frames must be enabled for each vSwitch or VMkernel interface through the command‐line interface on your ESX Server 3 host.

  • To allow ESX Server 3 to send larger frames out onto the physical network, the network must support Jumbo Frames end to end for Jumbo Frames to be effective.

  • Before enabling jumbo frames, ensure the NIC or LOM supports jumbo frames.

  • VMware supports jumbo frames with the following vendors:

    • Intel (82546, 82571),

    • Broadcom (5708, 5706, 5709),

    • Netxen (NXB-10GXxR,

    • NXB-10GCX4),

    • Neterion (Xframe, Xframe II, Xframe E).

Creating a Jumbo Frames-enabled vSwitch
  1. Log in directly to your ESX Server 3 hosts console.
  2. Run the esxcfg-vswitch -m <MTU> <vSwitch> command to set the MTU size for the vSwitch.
    This command sets the MTU for all uplinks on that vSwitch. Set the MTU size to the largest MTU size among all the virtual network adapters connected to the vSwitch.

  3. Run the esxcfg-vswitch -l command to display a list of vSwitches on the host, and check that the configuration of the vSwitch is correct.

Creating a Jumbo Frames-enabled VMkernel interface

To create a Jumbo Frames-enabled VMkernel interface:

  1. Log in directly to your ESX Server 3 host’s console.

  2. Run the esxcfg-vmknic -a -i <ip address> -n <netmask> -m <MTU> <portgroup name> command to create a VMkernel connection with Jumbo Frame
    support.

  3. Run the esxcfg-vmknic -l command to display a list of VMkernel interfaces, and check that the configuration of the Jumbo Frame‐enabled interface is correct.
    Note: ESX Server 3 supports a maximum MTU size of 9000.

Microsoft Windows 64bit operating systems (Vista, 2003, and 2008) randomly fail

KB Article
1006576

Products
VMware ACE

VMware ESX

VMware ESXi

VMware Fusion

VMware Player

VMware Workstation

Product Versions

Any

Symptoms

  • Your Windows operating system fails or stops responding

  • A computer that is running an x64-based version of Windows Server 2003, Windows Vista, or Windows Server 2008 randomly restarts and generates a Stop error

  • The Stop error code may be:

    • 0x0000001E

    • 0x000000D1

    • or another Stop error code

Resolution

This is a Microsoft issue caused by a patch.

This problem occurs after you install Microsoft update 932596 on the computer. For more information, refer to http://support.microsoft.com/kb/950772.

Addtionaly,

Make sure to know the proper trouble shooting method’s when running A Fiber Channel array via VMware.

Troubleshooting ESX and ESXi connectivity to fibre channel arrays

Troubleshooting fibre channel storage connectivity

These both outline it well.

Thanks to The VMguy and VMware for the content.

Full Source Post http://vmguy.com/wordpress/index.php/archives/479

theVMguy’s Notable KB articles from the week

http://vmguy.com/wordpress/index.php posts his weekly Notable KB articles from the week.

 

 

Apparently the VMware support team got back to work full steam ahead this week.  81 articles were new or updated this week.  There are some really good troubleshooting ones this week.  Here’s this week’s selection:

Thanks to the VMguy, and VMware for Content.

A few of the articles that caught my eye.

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=3443266

Converting a virtual disk into a Raw Device Mapping

KB Article
3443266

Updated
Jan. 12, 2009

Products

VMware ESX

Details

What is the command to convert a virtual disk into a Raw Device Mapping in ESX environment?

Solution

A virtual disk can be imported into a raw LUN for use with an RDM using following commands:

  • For virtual compatibility mode use: vmkfstools –i <srcfile> -d rdm:/vmfs/devices/disks/vmhbac:t:l:p /vmfs/volumes/datastore/vmdir/vmname.vmdk

  • For physical compatibility mode use: vmkfstools –i <srcfile> -d rdmp:/vmfs/devices/disks/vmhbac:t:l:p /vmfs/volumes/datastore/vmdir/vmname.vmdk

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003228

GHO image files cannot be converted

KB Article
1003228

Updated
Jan. 09, 2009

Products

VMware Converter

Details

  • Cannot select Symantec Ghost/Norton Ghost image files as source for a virtual to virtual conversion
  • .GHO files cannot be selected as a source

Solution

Image files created as .GHO format are not supported by Converter. You must use an image format with the file extension .sv2i.

The following Symantec formats are supported by Converter 3.x:

  • Norton Ghost version 9.0, 10.0, and 12.0 (.sv2i files only)

  • Symantec Backup Exec System Recovery (formerly LiveState Recovery) 6.5 and 7.0

  • LiveState Recovery 3.0 and 6.0

A detailed list of supported formats for VMware Converter 3.x is included in the Converter 3.0.3 User’s Manual.

 

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1007654

 

SCSI and Jumbo Frames configuration on ESX 3.5

KB Article
1007654

Updated
Jan. 05, 2009

Products

VMware ESX

Product Versions

VMware ESX 3.5.x

Symptoms

  • Large queues are seen while monitoring Jumbo Frames

Purpose

This article provides information related to setting up an iSCSI environment with Jumbo Frames.

Resolution

Important Jumbo Frame Information

The following is important information to know when using Jumbo Frames:

  • Any packet larger than 1500 MTU is a Jumbo Frame. ESX 3.5 supports frames up to 9kB (9000 Bytes). They are limited to data networking only (virtual machines and the VMotion network) on ESX 3i/3.5.

  • Jumbo Frames are not supported for NAS and iSCSI traffic at this time.

  • Jumbo Frames must be enabled for each vSwitch or VMkernel interface through the command‐line interface on your ESX Server 3 host.
  • To allow ESX Server 3 to send larger frames out onto the physical network, the network must support Jumbo Frames end to end for Jumbo Frames to be effective.

  • Before enabling jumbo frames, ensure the NIC or LOM supports jumbo frames.
  • VMware supports jumbo frames with the following vendors:

    • Intel (82546, 82571),

    • Broadcom (5708, 5706, 5709),

    • Netxen (NXB-10GXxR,

    • NXB-10GCX4),

    • Neterion (Xframe, Xframe II, Xframe E).

Creating a Jumbo Frames-enabled vSwitch
  1. Log in directly to your ESX Server 3 hostʹs console.
  2. Run the esxcfg-vswitch -m <MTU> <vSwitch> command to set the MTU size for the vSwitch.
    This command sets the MTU for all uplinks on that vSwitch. Set the MTU size to the largest MTU size among all the virtual network adapters connected to the vSwitch.

  3. Run the esxcfg-vswitch -l command to display a list of vSwitches on the host, and check that the configuration of the vSwitch is correct.

Creating a Jumbo Frames-enabled VMkernel interface

To create a Jumbo Frames-enabled VMkernel interface:

  1. Log in directly to your ESX Server 3 host’s console.

  2. Run the esxcfg-vmknic -a -i <ip address> -n <netmask> -m <MTU> <portgroup name> command to create a VMkernel connection with Jumbo Frame
    support.

  3. Run the esxcfg-vmknic -l command to display a list of VMkernel interfaces, and check that the configuration of the Jumbo Frame‐enabled interface is correct.
    Note: ESX Server 3 supports a maximum MTU size of 9000.

The VMguy’s Notable KB articles for the week

I want to thank The VMguy for his weekly Notable KB articles for the week.

Here they are again, me just copying and placing it on the blog.

Sorry for the late post. The VMware support team never sleeps. Here’s a few articles new or updated this past week:

Full Post http://vmguy.com/wordpress/

The Investigating disk space on an ESX host caught my attention, and I will expand on what it says below.

Symptoms

  • Virtual machine fails to power on with following error message:
    Could not power on VM: No space left on device. Failed to power on VM

  • The management agent (hostd) cannot start because the root partition is full

  • The VirtualCenter agent (vpxa) cannot start because the root partition is full

  • The system cannot create any new files or directories on / or /tmp partition, with the error:
    no space left on device

  • The /tmp directory is filled with cimclient_root* logs, potentially thousands (~600,000 or more)

  • The vpxa log may contain these error:

    [2008-10-13 11:02:05.423 ‘Libs’ 3076454304 warning] Cannot make directory /var/run/vmware/root/27591: No space left on device
    [2008-10-13 11:02:05.423 ‘App’ 3076454304 error] Exception: Failed to initialize authd server
    [2008-10-13 11:02:05.423 ‘App’ 3076454304 error] Backtrace:
    [00] eip 0x909dd92
    [01] eip 0x9043444
    [02] eip 0x907f975
    [03] eip 0x908024c
    [04] eip 0x9033d74

  • VMware VMotion failure at 10%

Purpose

For troubleshooting purposes, it may be necessary to check the available free disk space on your ESX host. This provides you with the steps to check the available disk space and steps to free up space if required.

Resolution

Checking disk space usage on the ESX Server service console partitions

To check the free space on an ESX Server service console partitions:

  1. Log in to the ESX Server service console as root from either an SSH session or directly from the console of the server.

  2. Type df -h.

  3. When you have finished reviewing the output, type logout and press Enter to exit the system.

The output appears similar to:

Filesystem Size Used Avail Use% Mounted on
/dev/sda2 4.9G 3.0G 1.6G 66% /
/dev/sda1 99M 18M 77M 19% /boot
none 145M 0 145M 0% /dev/shm
/dev/sda7 2.0G 135M 1.7G 8% /var/log
[[email protected]]#

Note: The partitions shown are from a default installation of an ESX host. If you have modified the partition configuration the output may show differently.

Review the Use% for each of the listed items. If any of the volumes listed are 100% full they must be investigated to determine if space can be freed. The most important mount points to investigate on a default installation of ESX are the / and /var/log mounts because if they are full they can prevent proper operation of the ESX host.

Checking disk space usage on a VMFS volume of an ESX Server

To check the Free space on a VMFS volume of an ESX Server:

  1. Log in to the ESX Server service console as root from either an SSH session or directly from the console of the server.

  2. Type vdf -h.

  3. When you have finished reviewing the output, type logout and press Enter to exit the system.

The output appears similar to:

Filesystem Size Used Avail Use% Mounted on
/dev/sda2 4.9G 3.0G 1.6G 66% /
/dev/sda1 99M 18M 77M 19% /boot
none 145M 0 145M 0% /dev/shm
/dev/sda7 2.0G 135M 1.7G 8% /var/log
/vmfs/devices 439G 0 439G 0% /vmfs/devices
/vmfs/volumes/458865ba-b31110fd-43d5-00127994e616
68G 47G 20G 69% /vmfs/volumes/San_Storage
/vmfs/volumes/45b5eb1a-808343db-ecab-00114335854b
26G 9.7G 16G 36% /vmfs/volumes/Local_Storage
[[email protected]]#

Note: The partitions shown are dependant on the VMFS volumes you have defined and presented to the ESX host.

Review the Use% for each of the listed items. If any of the volumes listed are 100% full they must be investigated to determine if space can be freed. If a VMFS volume is full you cannot create any new virtual machines and any virtual machines that are using snapshots may fail.

Freeing disk space on an ESX Server

Freeing disk space can become a large task if there has not been any recent changes to the ESX host. There are a few common reasons that partitions become full:

  • Information, such as a virtual machine or an ISO, was copied to the system.

  • Snapshots are being used on virtual machines.

  • Log files have not yet been rotated after a substantial amount of information was written to them.

There are also several common places to start for determining what is taking up the space on the volume:

  • The /vmimages folder. This folder is used to store operating system install files such as the VMware Tools or other ISO files.

  • The /var/core folder. This folder is used to store crash files for processes on the service console.

  • The /var/log folder. This folder stores the majority of the logs for the ESX host.

  • Any VMFS volume. These are used to store the virtual machine data.

If you are unable to determine where the space is being used, you can run the following command:

[[email protected]]# find / -size +10240000c -exec du -h {} ; | less
This command provides a list of all files that are larger than 10MB in size. See the Additional Information section of this article for more options on tweaking this command.

After you have determined what is taking up the free space you can use the rm command to free up space by deleting files.

Warning: When you delete a file there is no way to recover it, so use caution when deleting anything.

The following are a list of files that are safe to delete:

  • Old vm-support logs.

  • Virtual machines that are not being used and are not needed

  • ISO files that were copied to the system
    Note: Do not delete the VMware Tools ISO files.

  • Old log files that are no longer needed.

  • Virtual Machine log files can be removed if there are a lot (thousands) of vmware*.log files in the virtual machine’s folder. You may need to delete the vmware*.log files using “rm vmware*.log” or if there are too many arguments for this to complete successfully you can try using “rm vmware-1[1-5]*.log” followed by “rm vmware-1*.log”, “rm vmware-2[1-5]*.log” followed by “rm vmware-2*.log”, and then “rm vmware*.log”. This will delete all the log files for this virtual machine.

If you are unsure about deleting a specific file please contact VMware Support for assistance with this. If a system file is removed inadvertently this may cause damage to your ESX host that can require a re-installation of the software.

Additional Information

Note: Recommended partition sizes can be found in the “Datastore Partitioning” chapter in the VI3 Install & Upgrade guide which can be found at http://www.vmware.com/pdf/vi3_301_201_installation_guide.pdf

Note: Here are additional ways to use the find command:

  • To look for files larger than 1MB, change the command so that-size is: +1024000c

  • The find command listed above looks through the entire file system tree. The-mountswitch will stop find from crossing mount points. This is useful as you don’t want to look in the/vmfs part of the tree, since all the files there are big and not what you are looking for.

I know to some of you this is wasted space, but I wanted to remind both my self and others on how important disk space is when it comes to your VMware Host.

If time permits, I would like to dig into ways to prevent this from happening.

Thanks to VMware and the Author of the source blog post.