Ok
1 - This has nothing to do with whether or not your library is set to random or sequential.
2 - This has nothing to do with whether or not volumes are dedicated to one library or the other.
What this has to do with is your switch process.
Something during the switch process is causing the controller for the VTL to get whacked and a new one is generated.
First, let's make sure the terminology is right. I am guessing you are talking about VTL as Virtual Tape Library and are NOT talking about simple Virtual Tape with the volumes on IFS files, right? I have used both.
What is happening is you have these items in WRKHDWRSC *STG. Some may be disk and some are for your VTL. The "whacked" ones may show up in STRSST, 1. Start a service tool, 7. Hardware service manager, 4. Failed and non-reporting hardware resources.
You can match the entries in WRKHDWRSC *STG with the resource name in WRKDEVD *MLB.
If, during your switch, you dynamically allocate one FC card from one lpar to another this will likely cause your issue. You might be better served by having VIOS serve up your FC card and have VIOS virtualize it to both lpars. I do switches all the time and do not have this issue. If you are not using FC but instead are using SCSI or whatever the interface is and you are dynamically allocating it from one lpar to another this will cause your issue also. Better to use FC and VIOS. Some may object to the additional cost of a FC switch, VIOS, etc. But I fail to find how having an operator work on the weekend to go into SST and clean up the mess and reconfigure the media library would be any less expensive. Especially as finding an operator you'd trust to go into SST would likely not be on the low end of a living wage position.
One alternative might be to use the "Change Resource Entry Information API" at https://www.ibm.com/docs/en/i/7.5?topic=ssw_ibm_i_75/apis/hw1.html to rename TAPMLBxx to the right name. Or you could use https://www.ibm.com/docs/en/i/7.5?topic=services-media-library-info-view to get a list of your current media libraries, find whatever one is current today, vary it off, rename it from TAPMLBxx to TAPMLB01 (or whatever you are calling it in BRMS) and vary it back on. Heck you might even want to start calling it something unique so as to never worry about autoconfig using the same name. For example even if the entry in WRKHDWRSC *STG is TAPMLB07, there's nothing stopping you from using script to vary off TAPMLB07, change MYBRMSMLB to use resource name TAPMLB07, then vary MYBRMSMLB on. IDK if all of this, along with "Media and Storage Extensions" trapping stuff would start to confuse the daylights out of BRMS.
I do switches, use BRMS, etc and with the FC virtualized by VIOS I have no such issues.
But I do think this may be what your problem is.
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Robert Berendt IBMChampion
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Original Message:
Sent: Wed August 14, 2024 11:33 AM
From: Michael Ruth
Subject: Backup Issue
Good day,
I am having an issue where my backup on my Dev system has always been running under TAPMLB03, in Media Library Services. For some reason after the Friday night back and when the weekly backup is to start Saturday night, something causes a switch to TAPMLB02. I go into BRMS and make my changes to TAPMLB02 and then by the weekend it switches back to looking for TAPMLB03. The tape drive is TAP04, which I'm sure no relevance. When I look at the adapter card for the failing device and it says not operational, and it flip flops back and forth. Don't really see anything in the log. Ideas?
Michael Ruth
iSeries Support – SiteOps IT North American MQ & RD
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