One tape device on the shared bus

Question

We are clustering PE2650, and PV220S in an active/passive mode. We have one tape drive PV 110t LTO2.   I am  connecting to the PV220s via PERC 4DC I want to connect the tape drive via the adaptec 29160U.   How do I do a two node cluster with tape device on a shared scsi bus?   What are the cables, terminators required. What SCSI ID should i use? How should the termination be?   Thanks

dell-richard g · Answer

DELL does not support clustering with tape on a shared SCSI bus.  Only fiber channel SANs support tape clustering.   Here's the way you would nomally do this:   1.  SCSI adapter in each server. 2.  Server 1 connects to connector 1 on the tape drive via a SCSI cable. 3.  Server 2 connects to connector 2 on the tape drive via a SCSI cable. 4.  No termination on the tape drive since both connectors are already in use. 5.  On each adapter, you MAY have to set a jumper on the adapter for self-termination.  Check your adapter documentation or contact Adaptec. 6.  With applications like Backup Exec for Windows, if there is a cluster failover, Backup Exec will clear any SCSI reservations on the tape drive by issuing a BUS Reset.    Also, you may want to check with the tape drive vendor just to make sure they have no problems with a shared SCSI bus.   A safer way to do this is to setup a third server (backer server) to back up the active node in the cluster via a dedicated 1Gb NIC. In the event of a cluster node failure, resources will move to the failover server and the node can still be backed up by the backup server via the virtual node name.   One drawback is that if the back server goes done, there would be no failover of the backup server since it is a single server.  This type of setup is lowcost and you can get excellent speed via the dedicated LAN.

drtop · Answer

Thank you very much Richard for your prompt response. I am trying to find any documentation of self termination of the Adaptec 29160U, I am not able to find, please help me.

I have another situation, where both Server1 and Server2 are int Active/Passive Cluster mode.

I am

Connecting from Server 1 via the Adaptec 29160U to the first LTO2 tape drive of the PV 114T.

Connecting from Server2 via the Adaptec 29160U to the second LTO2 tape drive of the PV 114T.

I would like to achieve that my Server1 and Server2 see both the Tape drives. How can I do this?

What cables and terminators are required?

What SCSI ID's should be set?

What changes are needed on the Adaptec 29160U?

Thanks

dell-richard g · Answer

The way you would connect it is as follows: (each tape drive has two connectors)   Server 1 ----> tape drive 1(connector 1) Tape drive drive 1 (connector 2) -- >tape drive 2 (connector 1) Tape drive 2 (connector 2) ----> Server 2.   The terminator is done withing the scsi adapter itself.  (each end of the bus is terminated.)   You will need to set different IDs for the tape drives and scsi adapters.  (i.e. 4 different IDs).   I would contact adaptec and ask them about the termination needed on a multi-initiator setup as you have.  It is eaither auto-terminated in the adapter or it may require a jumper on the adapter.  We do not offer this adapter, so I am unable to check this.    As far as a cable, you can use any scsi cable that is LVD capable (low voltage differential).  DELL offers such cables, but I do not have part numbers.   No other changes are needed on the adapter.  Once again, DELL does not support this type of setup.

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One tape device on the shared bus

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