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IBM librairies TS3500 lin_tape issue - Linux RH 7 MSDP installing wich driver ?

laguns97
Level 4

Hi !

We have a IBM librairies TS3500 with 60 tapes drive. We installed new Linux RH7 server for MSDP use (Netbackup 7.7.3) .  Last week I tried to install lin_tape driver but but not working.... 

With the /usr/openv/volmgr/bin/scan command, all "Device Name" was "-". 

So I removed the lin_tape driver and tried with the generic driver of RedHat7.  Everything work fine.  We would like to use the Control Path Failover (set to on) and Data Path Failover (set to off)but I read somewhere that this option is only available with lin_tape.

Did anyone here install this driver (lin_tape) ?

Another question about the persistent name support for tape device.  It is correct to insert this line "AUTO_PATH_CORRECTION = YES" in the vm.conf file or it is better to do this in udev utility ?

 

Thanks for your help !

 

Steve

4 REPLIES 4

Thoth
Level 3

To be honest, I don't recall any version of NetBackup working well with dual paths for tape drives, and I'm presuming FC connections of some sort here. I've never worked with lin_tape so could be utterly out to lunch on the topic.

Wrt. the question about persistant names - it starts with first using persistant binding at the Fabric layer (as per my earlier assumption) If drive X in library N is always found at Controller 1, target 2, lun 0, you should have no issues. AUTO_PATH_CORRECTION is a nice safety net, esp. on Windows where you sometimes simply can't control anything because a driver writer thinks they know more than you do. 

Messing around in UDEV will get you into trouble eventually when that Drive X I mentioned fails, and gets replaced with Drive XYY in the same position as Drive X was in the library but presents a diff. SN and firmware version - the AUTO_PATH_CORRECTION will help protect from that as well, and removes the need to mess with UDEV.  From the times I played with UDEV, you'd have to remember to go manually update the UDEV mapping.  That's ok for a small env. but in a large one, with 60 drives? Human error is your enemy.

In theory, AUTO_PATH_CORRECTION is enabled by default for Linux and Windows, but I have actually found that occaisionally you do need to explicitly set it because Windows is being ... Windows.

You sound like you have a complicated env. - keep your config as clean and simple as you can to make managment as easy as possible.

Cheers!

Marianne
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If you look in the NBU Device Config manual (Linux chapter), you will see that NBU only works with built-in Linux st and sg drivers.

mph999
Level 6
Employee Accredited

Dual path for tape doesn;t work 'automatically', dual path for robot, I believe does.

Marianne
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@laguns97

Not sure if you have seen previous replies.

Herewith extract from NetBackup Device Configuration Guide

About the required Linux SCSI drivers
To use SCSI tape drives and robotic libraries, the following drivers must be configured in the kernel or loaded as modules:
■ Linux SCSI generic (sg) driver.
    This driver allows pass-through commands to SCSI tape drives and control of robotic devices.
■ SCSI tape (st) driver. This driver allows the use of SCSI tape drives.
■ Standard SCSI driver.
■ SCSI-adapter driver.

The standard Enterprise Linux releases have the sg and the st modules available for loading.
The modules are loaded as needed. Also, you can load these modules if they are not in the kernel.
Use the following commands:
/sbin/modprobe st
/sbin/modprobe sg

..........
You can use the /sbin/lsmod command to verify that the st and the sg drivers are loaded in the kernel.