DL380G4 and SDLT 320

[Daniel Rodríguez]

Hi,

I´m having a problem that I do not understand at all.

I have a DL380G4 and a HP StorageWorks External SDLT 320, so when I connected the SDLT on the external SCSI Port, The OS (W2K) showed me an error "Unknown Hard Error", then Reboot and on the booting I Received the message " SCSI Bus Termination Error, " Internal and External Drives CANNOT be both attached to the same SCSI port (Controller is Disabled until this problem is solved". After that it keeps rebooting until I disconnect the external unit from the External Port. If I cannot use the external port, what is it intended for? Do I neeed to buy an SCSI CARD? Is there any kind of HW modification I can do to make ir work? If so, what about the performance?.
Thanks in advance for your help

[Steven Clementi]

Daniel:

If your g4 is configured so thatthe front HDD cage is in "duplex mode", then you can not use the external scsi port. The cage has to be in simplex mode to use the external port.


You could connect a 4314R or 4354R Disk shelf to the server without having to buy an extra card.

It would be best to purchase a secondary SCSI adaptor to use with the tape drive as you will get the best performance from it. In some cases, the Tape drive may work on the Smart Array, but the performance will be DOG SLOW. Other cases, it won't work at all.


Steven

[Russell C. Smith]

Hi Daniel,

Firstly, your first stop for HP server and tape drive compatibility is http://www.hp.com/go/connect. It's a very useful first check for connectivity information. Having check this link for your particular server/tape drive config I can confirm that it is HP supported so you're off to a good start.

Now, based on what you've said, and in particular the error message "SCSI Bus Termination Error" I would first recommend that you check that you've properly attached a terminator on the back of the SDLT 320. The SDLT 320 has two ports at the back. You should plug the cable to computer to one port and, on the 2nd, attach an appropriate multimode LVD/SE terminator.

If that's done, and you're absolutely sure that that's not the problem then I would suggest that you check that the device ID number isn't set to 7. To do this, look at the back of the drive and you should see a small numerical dial, which you can manually set the number by poking the + and - keys above and below it. Make sure it's not set to 7 because 7 is normally reserved for the adapter card it connects to. It's a SCSI thing, you can't have more than one device with the same number on a single channel and the adapter card also has to have one of these numbers.

If after changing this number (even if it's not 7 try changing it to something else) then I suspect that you are already using the channel that the external port is connected to and what Steven has said about Simplex/Duplex configurations is correct. Basically, in a Simplex config all the hard drives you connect to the system is connected via one SCSI channel leaving the extra in-built channel free for the external port and you could connect your tape drive. However, if your system is using the Duplex config, which it would seem at this point, both in-built channels are being used for all your hard drives, in which case you can't use the external port. If this is the case I concur with Steven and would recommend that you buy an additional separate SCSI adapter for the drive. You can find information about supported SCSI adapters via the link I gave above, which is a general link, or via this link that's more specific to your needs:
http://www.hp.com/products1/storage/compatibility/tapebackup/ISS/detail/16-0020-0059.html

To find more information about Simplex/Duplex configs check out http://docs.hp.com/en/hw.html

Hope this helps.

[Daniel Rodríguez]

First of All, Thank you both for the prompt responses.

My next question would be, where can I check this configuration (simplex or duplex), but I think I do not need to, because on the front of the server you can read the words Simplex and Duplex printed, and the word duplex is marked, so I guess it means it is configured to work on Duplex Mode, but there is something I still do not get, What is that external port intended for?.
I think (still reading about) duplex mode is intended to improve the performance of the server, do not know exactly how...yet, and I am not sure if it (duplex mode) can be disabled

On the other hand, before I bought this server I contacted HP technical Support to check if could connect this SDLT external Unit (Compatibility) to that external port and the answer I received was literally "As long as you have that port free, you can use it to connect the SDLT". My answer to that was, Ok I think there is no problem because I will connect only 4 internal 36,2 Hard Disks, and I did not receive any feedback after so I think the phrase "port free" can be misunderstood.
Again thanks for your help I am now finding out availability of 268351-B21 - Dual-Channel Ultra320 SCSI HBA
374654-B21 or Single-Channel Ultra320 SCSI HBA G2, Hopefully it wont take too much time because this unit is intended for main Backup.

[Steven Clementi]

Daniel:


If you open up the ACU on the server, and look at the "more Information" link when you select the controller, you should see 2 drives on 1 channel and up to 4 drives on the second channel for duplex mode. For simplex mode, all drives will be on 1 channel.

Another way to check is to lift the top cover off. If behind the middle of drives 0/1 and 2/3 you see a clear plactic connecter, then you are in duplex mode. It is connected to the BACK side of the board that the hdd's connect to.

Duplex improves the performance by allowing you to put 1 or 2 drives on 1 channel and 1 to 4 drives on another channel... allowing you to fully utilize both channels for all I/O instead of limited it to one channel. The external port can be used for external disk shelves. Suppose you eed to connect 14 more drives. You get a 4314R or similar and connect it to the external port. You can also connect an MSA500G2 to the external port.

The words on the front tell you which ports will get which ID's when you are in simple or duplex mode, that is all.
Simplex:
Ch1:4 - Ch1:3 - Ch1:1
Ch1:5 - Ch1:2 - Ch1:0
Duplex:
Ch2:3 - Ch2:1 - Ch1:1
Ch2:4 - Ch2:0 - Ch1:0

If you change your server to simplex mode, which you should be able to do without any data loss, then you would be able to utilize the external port for the tape drive, but as stated earlier... the performance just... well... sucks.

Keep on the route of getting the SCSI hba. You will me much more happy once installed and configured.


Steven

[Daniel Rodríguez]

Hey Steven, Again Thanks for your help.

Based in what you wrote I tried a what I thougt was a "logic" move. I checked in the front of the server and It shows that the 2 HD spaces on the right end belong to channel 1, while the 2 spaces in the middle and the 2 on the left belong to channel 2. I had connected 2 disks on the right end and two in the middle spaces, so I removed the two disks in the right end and put those Back in the left end (there is only OS W2k installed) so all of the disks are on the same channel (at least I think so). My bet was if they are all in channel 2 and External Scsi Port is on Channel 1 it could work...Wrong!!. I got the Same error message. After this try I installed the ACU to check the Controller, almost everything looks fine, it says all disk are connected to port 1, but the Controller State keeps refreshing (never Stop) while all HD leds are Blinking; I am not sure if it suppose to be that way.
If I change the server to simplex mode (to use for a while to RUN veritas backup application, and data Management) when I change it back to duplex to run more applications it will give me more configuration problems, wont it?

Regards.

Dan

[Steven Clementi]

I believe only challen 2 is ported to the external connector, so yea, your test was not good.

The only thing you can do is change to simplex mode. If you change now. you should have relatively no problem. The Smart Array 6i should notice the channel change, regodnize the disks in the new location and reconfigure the array based on the new positioning. When you want toswitch it back, it should be the same thing. I have nover switched back nd forth like that so Ican not speak from experience, but I do know the Smart Array is "smart" enough to figure out where the drives are. I would think you would have no problem going back to duplex.

Even after you install software and stuff.. the system partitions aren't going to change. You will still have a C: partition and whatever other drive partitions you creae. Only the SCSI id changes and is handled at the controller level. The OS does not even know you made a change.


Steven

[Daniel Rodríguez]

Hi again Steve,

So just to be sure, the easiest way to change to simplex mode is to remove the clear plastic connecter you mentoned above or is there another way to do it?

Dan

[Steven Clementi]

I think that is the only way, but not sure. I have only always used the terminator block. On = duplex, off = simplex


Steven