Should Redhat VMs share VMware hosts with Windows guests?

I believe no, here’s why:


Benefits of dedicated Red Hat VMware environment:

     1. Licensing benefits:

Components used in Redhat environment: MySQL, Red Hat Linux, Red Hat high availability extension, Red Hat resilient storage add-on, Redhat Scalable Filesystem (for CIFS/NFS), JBoss, Oracle.

If we share , all VMs will need a license/subscription ( same cost as unlimited guest license, yes). Suppose we built 20 VMs on difference ESX clusters, we will have to spend $3000 x 20 = $60000 per blade per year in license for just Redhat OS compared to just $3000 x 1 = $3000 per blade per year (unlimited guest type). Interestingly they cost same in Redhat.  Also, this is per year license ( called subscription). All RedHat products that we intend to use, work on same licensing model. ( JBOSS, RedHat Cluster, cluster filesystems. We are going  to use these products for windows samba fileserver cluster etc also).

This is huge benefit in cost because, each software has its software licensing similar, like ( mysql 1-2 core ($12,000/year) – hence 1 license per blade will be needed, for unlimited guests on a  dispersed environment will need one for each VM ( 20 vms will need 20x$12000/year =$240,000 per year just for mySQL), all others are like this and extremely high.


      2. Architecture benefits:


  • The VMware configurations to allow a VM to kill  another VM when required (needed in HA and clusters) and can be enabled securely safely in Redhat dedicated environments. (windows and Redhat environments are managed by separate groups in my company.
  • Easy resource management and planning as blade dedicated to Redhat ( again because windows and Unix is managed by different groups.
  • Ability to take file system snapshots of VM is for quick backout of a change. (it is disabled in windows server Vmware hosts as they have a different mindset and set of problems in windows environment) – We already use this in zLinux ( logically) by taking DDR copy backups, we won’t get those features if we share with windows due to the storage restrictions.
  • All VMware Enterprise features like VMware HA, VMotion, Storage VMotion, and DRS will be unusable unless in dedicated cluster because some of them like DRS are not usable until all RedHat, mysql  etc licenses are aligned with Unlimited guest type licenses .


  3. Functionality benefits:


Unix team will be able to manage VMware storage/networking/spin VMs and leverage on VMware support team for VMware ESX server level configuration/maintenance. This is because they give us more control options on our dedicated blades. This speeds up our delivery time drastically and builds the skill across the teams.

  • Ability to disable/enable ethernet connection, create internal vswitches for clusters, iSCSI filesystems etc (by Unix group)
  • Ability to clone a VM at odd hours, change time. (by Unix group)
  • Ability to change CPU and memory of guests and when required (by Unix group as we do in zLinux)


For HA strategy and to even begin with it, dedicated Red Hat environment will enable one to configure the VMware options, on storage, networking, snapshotting etc to support Red Hat environment in a better manner.

Because LINUX is not as resource hungry as Windows, dedicated environment will ensure availability performance configurability according to HA and other configurations.

I guess I made my point


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