Hello,
I've got a problem with Tape Drives after upgrading from ESXi4.1 to 5.1.
The Tape Drive is connected to a 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI Device but when I click on details in Configuration => Storage adapters, there are no devices displayed. If I click on paths, there's an entry: vmhba2:C0:T5:L0 status: failed
If I try to start the VM where the Tape Drive was assigned befor the upgrade it shows up an error like "The SCSI-Device '/vmfs/devices/genscsi/naa.500e09efff0e8545' (scsi0:5) couldn't open: Could not find the file."
I also searched a bit on VMware community and found the following:
http://communities.vmware.com/message/1727618
But I've never used esxcli so I'm a bit scary about using commands I don't understand.
Our server: Dell Power Edge R805
Our tape drive: Quantum SuperLoader 3
Hope you guys can help me 
Think I found a solution for the problem in this community: http://vmware-forum.de/viewtopic.php?p=128555
I tried this on the esx-cli:
esxcfg-scsidevs -a
vmhba2 mptspi link-n/a pscsi.vmhba2 (0:35:8.0) LSI Logic / Symbios Logic 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI
esxcli storage nmp satp rule add --satp VMW_SATP_LOCAL --driver="mptspi" --description="Rule for local path of LSI-Controllers for Quantum SuperLoader 3"
After that the device showed up in storage devices and the path view showed status active.
They also shows up in the VM so I think my problem is solved
Massive thanks to Zeus, the first and third lines above helped me connect an HP Ultrium3 tape drive via an LSI Scsi card in a Dell server 
running ESXi 5.5