Virtualization Category

Installing Debian Linux on Xen error INVALID_SOURCE – unable to access a required file in the specified repository

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I am working on a new virtualization implementation based on XEN Cloud Platform (XCP). After installing first XCP based hypervisor I tried installing a Debian 6 Linux OS with “New VM” option that later failed with an error:

INVALID_SOURCE – unable to access a required file in the specified repository: file://tmp/cdrom-repo–XXXXX/install.amd/xe/vmlinuz.

After a while, I figured out where was the problem – Debian doesn’t have vmlinuz so you shouldn’t select a Debian template from the drop down list, but rather select “Other install media” and install Debian from an ISO DVD image.… Read the rest of this entry »

Vmware Vsphere error – A specified parameter was not correct spec.sharesinfo.shares

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I tried to edit resource allocation settings and got the following error using Vmware Infrastructure client:

A specified parameter was not correct spec.sharesinfo.shares

To fix the problem and edit resource allocation you should edit values directly from the virtual machine

Login in as Administrator into Vmware Virtual Center using Vmware Infrastructure client. Select the virtual machine you want to modify. Edit Settings. Click Resources tab. Modify the required resource values as required.… Read the rest of this entry »

A general system error occurred: Source detected that destination failed to resume

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If you Fiber Channel storage is slow you may experience the following error while performing live disk vMotion migration from one LUN to another:

A general system error occurred: Source detected that destination failed to resume

Default values for disk settings in Vmware Vsphere ESXi server console are:

disk.delayonbusy 400
disk.resetlatency 1000
disk.maxresetlatency 2000

You may want to increase these values to:

disk.delayonbusy 1000
disk.resetlatency 2000
disk.maxresetlatency 4000

And perform a LIVE disk migration from one LUN to another and see if you are experiencing timeouts…… Read the rest of this entry »

Error: Communication with the virtual machine may have been interrupted

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A general system error occurred: The system returned an error. Communication with the virtual machine may have been interrupted.

The above error was displayed in Vsphere Virtual Center client when I tried powering on ta virtual machine that was stopped for RAM changes. This virtual server was running for over a year without any problems. I was scared a bit at the beginning since it was a production server, but after restarting management agents on the Vsphere ESXi server (via console), I was able to power-on this problematic virtual machine.… Read the rest of this entry »

Time keeping on Suse Novell Linux 11 running under Vmware Vsphere

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If you are running Novell SLES 11 (32 or 64 bit) OS on Vmware Vsphere platform I have some good news for you. Keeping system time on this platform is very easy as long as you have an external NTP server. Below I have listed necessary configuration steps to perform on SLES 11 for best system time keeping.

Please note that this guide will also apply for SLES 11 installed on a dedicated hardware just skip the Vmware specific configuration.

Disable Vmware Tools time synchronization with the Host under “Edit settings” for the specific virtual machine. This requires virtual machine … Read the rest of this entry »

Vsphere recovery between two data centers

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It’s been a hot topic how to do a recovery after the failure between two remote data centers using Vmware Vsphere and Virtual Center. What if one of the data centers goes down and you want all your virtual machines to be running in a second data center? In this post I am not evaluating Vmware¬† Site Recovery Manager software that offers data center recovery – I should probably come up with a more detailed information about this software in the near future.

Remember, there will be downtime even if you intend to use Site Recovery Manager – in order … Read the rest of this entry »

My steps for updating ESXi Vsphere servers

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There are many ways how to upgrade ESXi servers, but below, I will compile a list of update steps I am performing.

We only use ESXi Vsphere 4 version with Standard and Advanced type licenses. All ESXi servers are connection to Virtual Center and managed from there.

1.) Download ESXi installable ISO from web site and burn it in CD
2.) Move all virtual servers to other ESXi hosts using vMotion or shutdown servers and use standard migration
3.) Enter ESXi host in “Maintenance mode”
4.) Disconnect FC storage uplinks
5.) Insert CD in CD tray – boot the … Read the rest of this entry »

Beacon probing uplink failover for Vmware Vsphere high availability

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In order to correctly use beacon fail-over probing for Vmware vSphere server network connectivity you need:

  • 2 physical uplink switches in failover set-up;
  • 3 physical uplinks in team per each vSwitch with beacon probing enabled;
  • 2 of the uplinks (each going into different uplink switch) must be active and the third physical uplink should be set-up as a Standby adapter.

Beacon probing also works if you are using Vlan trunks. The only difference is that in case of any uplink failure beacon probes will be sent to all vSwitch VLANs increasing traffic a little.

Keep in mind:

You cannot advertise … Read the rest of this entry »

Get ready your Vmware infrastructure for 6 or more core processors

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For quite some time Intel and AMD has released 6 core processors and their cost has gone down. You should evaluate your server infrastructure carefully if you need to buy these new 6 core or more powered servers.

From my own experience, CPU resources are not the bottleneck for most of the applications we are running on Vmware vSphere – it’s performance is great and CPUs are fast nowadays. We are usually running out of the RAM with our vSphere 4 ESXi servers and thus, recommend a minimum of 128GB RAM for Vmware Enterprise license powered servers and at least … Read the rest of this entry »

Shared disk datastore migration with vSphere

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We just got a nice “feature” when we migrated two virtual server all disks to a different LUN that use a shared disk for Oracle RAC. Guess what? The shared disk was somehow lost and each of the virtual servers now have a fully dedicated disk in size of the shared RAC disk. The shared RAC disk configuration was lost as well.

I guess we need to delete both these disks from the virtual machines and create a new configuration once again.… Read the rest of this entry »