Backup to Tape: SCSI Bus Config Help
 

I am definitely a Linux novice yet I am trying to configure a RHEL5 machine with the commercially licensed Zmanda application to backup to a Exabyte VXA320 drive. After many hours researching, I am stuck. It seems I have a problem with my SCSI bus configuration but that is about as far as my knowledge goes. Here are some details:

HP ML310 server with an Adaptec 29160 SCSI card and Exabyte VXA320 single tape drive cabled and terminated as an LV device.

The SCSI card is definitely recognized but the tape drive definitely is not.

/proc/scsi/scsi returns the following:

Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: ATA Model: ST3250620NS Rev: n/a
Type: Direct-Access ANSI SCSI revision: 05
Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: ATA Model: ST3250620NS Rev: n/a
Type: Direct-Access ANSI SCSI revision: 05

Why is the hard drive listed twice on separate hosts?

I've booted to the SCSI controller config but I am unsure what to change. It may be as simple as that.

Technically the tape drive I am using is unsupported by RHEL5 (https://hardware.redhat.com/list.cgi...ent/Peripheral), but I also know most tape drives should work as generic st0 devices, right?

Any help would be much appreciated. Thanks in advance.

Just a little more detail...
 

Could the fact that my server has a a RAID1 configure of SATA hard drives cause any sort of conflict? How can I tell if they are trying to use the same SCSI bus?

I ran through the SCSISelect utility that Adaptec provides with the controller's drivers and came up with the following details about the SCSI bus config:

The Adaptec SCSI controller is at SCSI ID# 7 and is listed as the "SCSI Controller", of course, as well as being "29160 A at Slot 03, 0A:04:00".

1.) SCSI Controller ID = 7
2.) SCSI Controller Parity is Enabled
3.) SCSI Controller Termination is Automatic (options are LVD/SE connector or SE Connector).
4.) The tape drive itself is terminated and the indicator light on the terminator is amber which it says is for LV) Could that be it? Change the SCSI Contoller Termination LVD/SE setting to "Enabled"?)

You're in pretty deep for a linux novice. ;)

I don't know that I can help you much, so I hope some linux hardware geek drops in. However, . . . when I set up my AIT5 drive on Solaris, plugging everything together properly and doing a reconfigure reboot brought up the scsi card and all that. I still had to configure the st tape driver. That required a technical document from Sony with specific changes to add.

Anyway, you clearly need to get mt working and be able to address the tape, tar something to the tape, etc., before launching into configuring and using your backup software.

You should also look through the section of your messages log that corresponds to booting up and see if any errors or conflicts are reported.

Need to ask some stupid questions here:
Does the SCSI controller BIOS recognize the tape drive during boot up?
I assume this is the only device on the channel and its ID something other then 7.
I assume the drive is powered on prior to the computer booting.

I would leave the termination setting as automatic.

Even though SATA uses the SCSI subsystem modules it is independent of the SCSI controller.

I wouldn't assume anything. I know this has to be a some sort or simple flag in the BIOS or controller settings, or a config file line...


Thanks for the replies, everyone. If I get this working with your help, drinks are on me. : )

1.) (in response to the first responder) Yes, I know I am in deep for a novice.
2.) I do not see the tape drive during boot, only the SCSI controller
3.) I have no idea what devices are on that channel (7). I do know that it is the hardware defaults for the controller. How do I determine what ID a device is using? I played around with the SCSI controller settings, changing channels, etc... and all I did was kill the server so that it wouldn't boot normally until I reset it to channel 7.
4.) Yes the drive is powered on and terminated.

Each device on a SCSI chain must have a unique ID. 7 is the default for the controller so the tape drive can be anything else (0-6,8-15). Most external SCSI devices have a push button counter switch on the back of the unit to change IDs and internal devices use jumpers.

There is a difference between the SCSI controller BIOS and the OS recognizing a device. If configured then during the boot process the BIOS will scan through the all devices IDs and display device information if found. The BIOS setup should also be able to see the drive. Does this happen when your computer boots? If the BIOS does not see the drive then its a hardware/cabling/termination issue. Could be a LVD/SE auto sense issue.

If the BIOS sees the drive then it is an OS issue. Make sure the SCSI controller (aic7xxx) and st modules are loading.

oops, posted my comments on the wrong thread. Edited out.