23 Responses

  1. Fatih Solen
    Fatih Solen at |

    Great article Michael thanks.

  2. Michael
    Michael at |

    Great Article. I am also testing Nutanix. As I did build to separate Nutanix clusters and Storage VMotioned the VM from Nutanix cluster one to Nutanix cluster two, it was slow. As I mounted the nfs datastore from Nutanix cluster one to two it was faster. If I understood it write in the first case it uses fsdm and in the second fsdm3. I don’t know if hardware offload is used
    Very helpful was also frank dennemans article. http://frankdenneman.nl/2012/11/06/vaai-hw-offloa
    Also helpful is the comment of Birk: If you use multiple Netapp Boxes in cluster mode, VAAI will offload the Storage vMotion task

    •fsdm – This is the legacy 3.0 datamover which is the most basic version and the slowest as the data moves all the way up the stack and down again.
    •fs3dm – This datamover was introduced with vSphere 4.0 and contained some substantial optimizations so that data does not travel through all stacks.
    •fs3dm – hardware offload – This is the VAAI hardware offload full copy that is leveraged and was introduced with vSphere 4.1. Maximum performance and minimal host CPU/Memory overhead.

  3. Michael
    Michael at |

    Your Article could mean, that we see maybe a new datamover with version 5.5 Update 1 when vsan is added? Good question is, what happens when we build a cluster one with 3 esxi hosts and a cluster two with 3 esxi hosts, An both is vsan enabled. Then a VM is storaged moved from cluster one to cluster two.
    For the old datamovers the problem still exists. This means VMware means a new one in ESXi 5.5 Update 1.

  4. Sebastien Simon
    Sebastien Simon at |