What flavour of SD are we talking about - Windows, or UNIX?
I've been literally yesterday through the same journey with SDW, so this is what I've learned:
"If the LUN that is not getting connected is a new LUN created via FilerView, it is not connecting because there is no recognizable partition the LUN. Make sure you create a partition, format the disk and assign a drive letter on the Windows host. Then Unmap the LUN from the filer and connect the formatted LUN using SnapDrive."
[credits go to bhavik]
You can find some more detailed description in this doc:
You have to 'manually' attach a LUN to a Windows host, i.e. map LUN to an igroup including intiators form that host; once it is done rescan disks on the host side (via computer management GUI or diskpart CLI) & then intialize disk & create a partition on it - all from the Windows side.
Then unmap it (it will disapear from Windows) & connect it again using SDW.
I am confused now - were you hoping to attach these LUNs without loosing their content?
So first things first: when you said they were mapped to ESX, how did it actually look like? Were these LUNs formatted with VMFS to hold VMDK files? Or did you use LUNs for so called Raw Device Mappings where guest VMs format them with their native file system?
If the former is the case, then you definitely cannot attach VMFS file system to a Windows host - ain't gonna work
If the latter, then what was the actual flavour of guest OS: 2003, 2008? Basic or Dynamic disk? MBR or GPT partition?
1. Originally had a VM on local storage of the ESX server. The VM had 3 x vmdk disks.
2. I created 3 seperate LUNs in NetApp and presented these to ESX so I could migrate the VM to Shared Storage and each VMDK to their respective NetApp LUN. So basically these LUNs are formatted with VMFS3 and house the vmdk and config files of the VM.
3. I then unmapped LUN 3 and have been trying to reconnect to this via SnapDrive whilst retaining the data.