How to prevent /dev/rmt* re-assignments

Hi all,

Sometimes, when I reboot my AIX server, my tape drive /dev/rmt# assignments change. This creates some tedious TSM work prior to and after a reboot of the server.
Is there a way to ensure that the /dev/rmt# assignments come up the same every time?

Thanks

hmmm, coming up every time the same *is* the default behavior. There must be something wrong with your machine.

I can only guess, but i suspect that something with the ODM is wrong and therefore the cfgmgr which runs at boot time tries (probably in vain) to correct that. Maybe the following helps: completely remove the tape drive from the ODM (use "rmdev -dl" generously) and make sure the tape drive shows up nowhere in the ODM (check CuAt and PdDv tables primarily). Then reboot the machine so that the drives configuration is written anew.

I hope this helps.

bakunin

Helo.
First of all, I'm not an expert in backup but here the experts have configured a script that, everytime the TSM server reboots, configures the tapes. It basically deletes the tape devices and then, hba by hba, configures them again, changing "alt_pathing" into "yes" when appropriate. This process, I think, depends on your configuration and must be mantained by hand.
I hope this helps.
Regards.

Thanks for the input... interesting posts. One states: "must be something wrong with machine", other states: "... everytime the server reboots, we reconfigure...".
Apparently, I'm not the only one who is seeing this behavior.

hm, this meant only that the reason is not something in AIX but in your machine. "wrong" was probably a stretch. For instance, hdisk devices (which are similar insofar as several equivalent ones are usually there) aren't changing every reboot either.

Maybe there is some script which deletes and reconfigures the devices upon (re)-boot time for some unknown reason?

bakunin

Hi

That is not the normal behavior of AIX. Different from Solaris where you have to make a persistent binding of the tape devices, AIX it's supposed to save all information about devices in the ODM DB so in the next reboot it will configure devices still connected based on information of that ODM.

You can use commands in order to review contents of your ODM:

odmget CuAt > /tmp/cuat
odmget CuDep > /tmp/cudep
odmget CuDv > /tmp/cudv
odmget CuDvDr > /tmp/cudvdr
odmget CuVPD > /tmp/cuvpd

is this environment a LPAR ?? if so, adapter where rmt devices are connected (either SCSI or HBA) is a desired or required resource at LPAR configuration ?

Hope this helps