2120S Raid Controller and DAT Tape?

[Jeff Vian]

Jay Daniels wrote:

>On Sun, Apr 11, 2004 at 06:11:39PM +0200, Alexander Dalloz wrote:
>  
>
>>Am So, den 11.04.2004 schrieb Jay Daniels um 17:09:
>>
>>    
>>
>>>I have a scsi raid controller 2120S with 4 scsi ibm 320 scsi drives
>>>installed and working.  The 2120S is the only raid card on the box and
>>>it also has a some type of hot swap card which all the drives are
>>>connected.
>>>
>>>So how do I connect my new scsi DAT tape drive to this box?  Will I
>>>need another raid card to run the scsi DAT tape drive???
>>>      
>>>
>>I do not know the SCSI RAID controller. If it can independent from it's
>>RAID functionality - and that is an important fact too, if your SCSI DAT
>>tape drive is LVD too like the hard drives - be used for a single SCSI
>>device, then you can plug in the DAT drive too. If the controller is
>>only a RAID controller, or no separate SCSI connector is free, or your
>>DAT tape drive is not LVD and thus would switch down the whole SCSI bus
>>to non-LVD speed then it is need that you build in an own SCSI
>>controller card for the tape drive. Of course that card has not to be a
>>RAID controller too. Check which SCSI type the tape drive is and then
>>get a controller card serving that SCSI tape with an outside connector.
>>
>>    
>>
>>>jay
>>>      
>>>
>>Alexander
>>    
>>
>
>It's a Seagate Scorpion 40 DDS-4 "internal" drive.
>
>The Scorpion 40 supports the following SCSI interfaces:
>68-pin Ultra 2 SCSI (LVD)
>68-pin SCSI Wide (single-ended)
>50-pin SCSI-2(requires 68- to 60-pin adaptor)
>
>I currently have my hard drives on an adaptec 2120S with hot swap
>card.  The cable runs from the raid adaptor to the card.  The 2120s
>card is a 64bit pci card.
>
>Also, I use scsi 5 raid array and don't know if that would require me
>to install the tape drive on another scsi adaptor.
>  
>
According to the Adaptec site the 2120S is raid5 hardware controller, 
ultra 320.

You cannot attach a non-raid device such as a tape drive to this adapter.

You will have to have an adapter appropriate for the tape drive to 
connect it.

>So is the 2120S considered an Ultra 2 SCSI (LVD)?  Do I need to go
>into the adaptec setup of the 2120s to setup the tape drive?
>  
>
No, and No.

>I do not want to purchase another expensive scsi card if possible. The
>server will hold up to 7 320 scsi drives but currently I only have 4
>and don't think I will add any more hotswap hard drives.
>  
>
You have no choice.  Hardware raid controllers do not support non-raid 
devices.

>I spent a lot of money for this tape drive and want the best
>performance!  Oh, I also need a ribbon cable - no cable in the box, or
>do I really need a cable?  The cable from the 2120s to the hot swap
>card is long and has extra connections!
>
>  
>
You need to check the specifications on the tape drive.
Is it scsi2 UW or scsi2 UW fast.

I suspect from the info you give and what I know of most DDS4 tape 
drives it is scsi2 UW and not likely faster.

If you want an inexpensive scsi adapter, an adaptec AHA2940UW or similar 
would work well.
You will need a cable to attach to the drive, and if the drive/enclosure 
is not self terminating you will also need a terminator for the end near 
the tape drive.
All scsi buses must be terminated at both ends.  The adapter will 
usually be one end, the furthest device is the other end.
jeff