Page History

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• new dynamic max (y) <= static max and  
• new dynamic min (y / memory_overprovisioning_of_cluster) >= static min.

Further reading - http://support.citrix.com/servlet/KbServlet/download/32307-102-691300/reference.pdf^{Image Added} http://wiki.xen.org/wiki/XCP_FAQ_Dynamic_Memory_Control#Introduction^{Image Added}

Vmware -
DeployVmCmd - 

During the initial deployment of the VM we enable the flags hotAddCpu and hotAdd memory true. These flags will be turned on if the guest OS supports it. Read http://partnerweb.vmware.com/comp_guide2/pdf/VMware_GOS_Compatibility_Guide.pdf^{Image Added}

ScaleVmCmd - 

During scaling up of vm, the new requested RAM and CPU are set if the flags are turned on.

NOTE - After dynamically scaling memory user "might" need to run a couple of commands on Linux OS for new memory to take affect. Read http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1012764^{Image Added}

Further reading - http://pubs.vmware.com/vsphere-4-esx-vcenter/index.jsp?topic=/com.vmware.vsphere.vmadmin.doc_41/vsp_vm_guide/configuring_virtual_machines/t_change_cpu_hotplug_settings.html^{Image Added}

DB Changes

• Introducing a global config - enable.dynamic.scale.vm. Enables/Diables dynamically scaling a vm. This can be used to turn off the feature and is available at the zone level. By default the feature is turned off for upgrade reasons.
• Introducing a global config - scale.retry. By default the value = 2. This is for number of tries before failing the scaling.
• A new column in "vm_template" table named "dynamically_scalable" of type tinyint(1) and the value is 1 if template contains XS/VMWare tools inorder to support dynamic scaling of VM cpu/memory otherwise 0
• "user_vm_details" table holds key value pair with key "enable.dynamic.scaling" and value is true if VM contains XS/VMWare tools inorder to support dynamic scaling of VM cpu/memory otherwise false

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