vSphere Storage Appliance

 View Only
  • 1.  Fibre Channel - Paths to a LUN

    Posted Jul 11, 2009 08:29 AM

    Hi, Could someone kindly confirm this from the vSphere Config Max document.

    Is this the maximum paths to a single LUN from an ESX4 host?

    If that the case a single ESX host can see max 256 LUNS

    256 LUNS x 16 paths = 4096 paths, however it also state max paths per host is 1024. So if I understand correctly "Total paths on a host"

    would be the limiting factor, and we can say based on the amount of paths per host that would limit the amount of LUNS it could see.



  • 2.  RE: Fibre Channel - Paths to a LUN
    Best Answer

    Posted Jul 11, 2009 08:38 AM

    Usually (in switched fabric with 2 HBA for each host) the number of path for each LUN is 4.

    So 256 x 4 = 1024.

    You can use more HBA to have more path, but in this case I think that the number of total LUN (for each hosts) will be smaller.

    Andre



  • 3.  RE: Fibre Channel - Paths to a LUN

    Posted Jul 11, 2009 08:45 AM

    Thanks Andre,

    I'm just going through this document to study for the VCP4 exam, are you able to explain the next two item's

    LUNs concurrently opened by all virtual machines = 256

    And

    LUN ID = 255

    Thanks Nicholas



  • 4.  RE: Fibre Channel - Paths to a LUN

    Posted Jul 11, 2009 08:53 AM

    I also are study for the VCP4 exam :smileyhappy:

    LUN ID start from ID 0, so the max id is 255.

    Andre



  • 5.  RE: Fibre Channel - Paths to a LUN

    Posted Jul 11, 2009 09:28 AM

    Thank's Andre,

    Now I just need to find out what LUNs concurrently opened by all virtual machines means exactly.

    Do you mind me asking what docs you are studying for the VCP4? I found this link quite usful. most link to VMware PDFs

    http://www.simonlong.co.uk/blog/vcp-vsphere-upgrade-study-notes/

    Thanks

    Nicholas



  • 6.  RE: Fibre Channel - Paths to a LUN

    Posted Jul 11, 2009 09:36 AM

    Do you mind me asking what docs you are studying for the VCP4?

    There are also some other links in VCP Community (http://communities.vmware.com/community/vmtn/certedu/certification/vcp)

    Andre