wiki:GENIRacksAdministration/InstaGENIVMAllocation

Version 1 (modified by lnevers@bbn.com, 5 years ago) (diff)

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InstaGENI Racks VM Resource Allocation

The default VM memory allocation in an InstaGENI rack is 1GB with the default image. Each Physical server host has 48GB of memory out of which 5GB is reserved for the server host itself and from the remaining memory, it is possible to allocate 43 VMs.

Additionally the Logical Volume Manager (LVM) disk space is shared along with the disk images. Any new user custom disk image when seen by the physical host server, is mounted as a local volume from the same 1TB disk as the available images. This is done so it may be later possible to just clone this new volume when a VM with the same disk image is requested. There is no reserved disk space for this feature, so it may vary across racks.

When it comes to disk space in the InstaGENI racks:

  1. There is the Disk image, which can be a user-created or a GENI/Emulab-provided images. These are standard compressed sized images . These images are less than 1GB in size for theGENI/Emulab-provided images. User-created images may be larger. When used, these images are cloned onto the space allocated to the VM.
  1. There is the default Xen VM Disk size. with a default of 20GB. This allocation started at 4GB, was then increased to 8GB and is now 20GB. This larger size was allocated to accommodate many experimenters that may want to run tcpdumps or generate large log files. The goal is to avoid running out of disk space on a VM, which would be fatal for the VM instance.