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MDRs and TL89x Libraries

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Eric Dittman
Frequent Advisor

MDRs and TL89x Libraries

I had a TL890 Expansion Unit that was controlling two TL892 Libraries. The TL890 and the TL892s were attached to an MDR (firmware 1187). This worked just fine. I added another TL892 and a TL890 Data Unit. The MDR could see the TL890 Expansion Unit and the six drives and mapped them but none of the remote systems could see the two new drives (OpenVMS, Linux, AIX). I did a "clearfcscsimap" and restarted the MDR. Again, the MDR could see everything and mapped them but none of the systems could see the two new drives (even after a reboot of the systems). The TL890 Expansion Unit and the first TL892 were attached to the first SCSI DIFF port of the MDR, the second TL892 was attached to the second SCSI DIFF port of the MDR, and the third TL892 was connected to the third SCSI DIFF port of the MDR. Since this didn't work I added another quad-port SCSI DIFF module to the MDR and moved the third TL892 over there. Again, the MDR could see everything but the systems still couldn't see the two new drives. After each configuration change I did a "clearfcscsimap" on the MDR and rebooted the systems (including deleting SYS$SYSDEVICES.DAT on the OpenVMS system before reboot and removing the devices and definitions on the AIX system before reboot).

Since this wasn't working, I moved the third TL892 to a completely different MDR (also running 1187 firmware) and did a "clearfcscsimap" on both MDRs followed by powering them off and back on and clearing the defined devices from the systems and rebooting them. The MDRs are still seeing all the devices but now the systems are seeing the TL890 Expansion Unit and first TL892 on the first MDR and the TL892 on the second MDR but not the second TL892 on the first MDR.

I can't think of anything else to try and was hoping someone else had an idea of where to look. I've attached a file showing the results of "showscsidevices" and "showfcscsimap" during the first round to show that the devices were all seen and mapped.
6 REPLIES
Mark Poeschl_2
Honored Contributor

Re: MDRs and TL89x Libraries

Could it be that you have some non-default maps set up for the host(s) in question?

Is the map update model in your configuration open or closed? (See the SetMapUpdateModel command. I seem to recall there was also a ShowMapUpdateModel, but I don't have access to the MDR CLI Guide to be sure.)
Claudio Ruzza_1
Valued Contributor
Solution

Re: MDRs and TL89x Libraries

Hhmmm, definitely a weird problem.

I've ran once in a similar behaviour. It turned out in a hardware problem: the internal SCSI cable of an TL89x (the "Y" shape SCSI cable) gave a tricky problem. Drives were shown correctly to the MDR but the systems weren't able to see them.

I do not have an immediate solution, but I can give my two cents.

I strongly recommend to set your map update model to "closed" and keep your default map empty. This prevents several problems.

Is the parameter ScsiSCCmode set to "OFF"? If set to on, MDR presents to SAN a further LUN, almost useless.

Have a look at the SAN switch zoning too. A good zoning criteria could be to create as many zones as the number of your servers. Each zone must include the server itself and the MDR ports. In case a server has more than one FC card you have to set up two zones, maybe with a couple of MDR ports mapped to 1st FC card, and the remaining ports to 2nd FC card.

HTH
Claudio
Claudio Ruzza_1
Valued Contributor

Re: MDRs and TL89x Libraries

Some more notes:

-I've read your attachment and it seems you have the parameter SCCmode to on. Please toggle it to off and re-create your maps

-Usually when the Default map is present, the MDR's mapping model is dynamic. It seems you are in this condition. I strongly recommend to switch to static model.

-run the MDR command "showhosts": it will show all the connected hosts WWNames. Please check if any undesired host is seeing the Tape library. When you will setup the static maps, do not create a map for those hosts. Remember to clear ths default map!

-In my previous post I made a mistake. my sentence should read as: "In case a server has more than one FC card you have to set up two zones, maybe with an MDR's FC port mapped to 1st FC card (assuming you have a single FC port per MDR), and the second MDR's FC port to 2nd FC card."

Claudio

Eric Dittman
Frequent Advisor

Re: MDRs and TL89x Libraries

Claudio, you were right. The problem was with one of the SCSI cables. I didn't think the cables were a problem since the MDR could see the drives but I went ahead and swapped the external cables first. One of my VHDCI68-HD68 cables was bad. I replaced it and now all the drives can be seen. Thanks!
Rick Dyson
Valued Contributor

Re: MDRs and TL89x Libraries

Eric: Wanted to comment that your description of problem and actions was very good! I have been working with MDR and TL892 and MSL5026 units a lot lately and know your pain! I ended up having a bad Active terminator on the TL892 that did not present any problem when it was directly connected to an old SCSI card on an AlphServer running OpenVMS... But was fatal when connected to the MDR.

For the others that responded to Eric: Kudos! and Thanks from me for your suggestions. I have noted them for my own environment, too!

rick
Eric Dittman
Frequent Advisor

Re: MDRs and TL89x Libraries

There was a bad SCSI cable.