1 Reply Latest reply on Oct 2, 2017 3:41 AM by Nick_Andreev

    Obscure VMFS behaviour - via iSCSI to a QNap

    continuum Guru
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      This weekend I was busy with a very obscure VMFS-recovery.
      An iSCSI-volume of a Qnap-storage had about 2/3 of its vmdk-files damaged.
      Those flat.vmdks that appeared to be damaged actually were moved 224 sectors towards the end of the physical VMFS-volume.
      So we could fix some of them by adding another vmdk of the same size to the VM.
      Then we booted the VM into Linux and cloned the disks like this:
      dd if=/dev/sda of=/dev/sdb bs=512 skip=224.
      This obscure offset is something I have never seen before.
      The VMFS-volume itself was properly alligned with a 1MB offset for the start of the VMFS-partition.
      Has anybody seen something like this before or has a theory which would explain such a behaviour ?
      Additional info: no Raid5 problems , no unexpected power failures , behaviour appeared with out any apparent problems or warnings before.
      Suggestions or theories are welcome.
      Recovery results so far: most important SQL-servers were recovered, we still have some problems with Windows 2008 and Windows 2012 boot disks that are readable but no longer bootable.
      Ulli