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Connecting Autoloaders in Daisy Chain

Sachin Sontakke
Occasional Contributor

Connecting Autoloaders in Daisy Chain

I have HP9000 L-Class (rp 5470) server with only one internal tape drive HP surestore DLT VS80 (which is in one of the Bay space of Storagework 5300 array).

I got two external auto loaders to connect to same server.
(DLT 7000 1/8 and HP SureStore DAT24x6e)

Now I want to install these two autoloaders in daisy chain.

I am not that good on Hardware. So could anyone help me and tell me how to set it up?

Can I use empty spaces of Array 5300 to plug in 1 of my autoloaders and connect them in daisy chain?

Please suggest me something.

Thanks
9 REPLIES
malvin drakley
Esteemed Contributor

Re: Connecting Autoloaders in Daisy Chain

Hi Sachin, The 5300 is normally an LVD/SE scsi device and the 1/8 autoloader is an HVD scsi device so you would not be able to connect it to your 5300. You would need something like an A4800A to connect your library to. The other thing to remember is that normally in order to stream your data to the tape device you only connect one drive per channel. While it is probably technically possible to connect the two devices together it is definitely not advisable
hope this helps a bit
malvin
Not me Chief, I'm Radar
Scott McIntosh_2
Honored Contributor

Re: Connecting Autoloaders in Daisy Chain

You need to figure out if that 1/8 DLT is single ended or differential. What's the sticker on the back say? It was sold both HVD and SE, depending on the target market.

The DDS is definitely single-ended.

Same question for the VS80. What is it? LVD, HVD/Diff, or SE?

And the DDS is narrow, while the 1/8 DLT and VS80 are wide. So not only do you have bus signalling conflicts, but also bus width conflicts.

I believe the integrated Ultra2 port on the rp is wide, not narrow.

Good luck,
Scott
HP Support
Vincent Farrugia
Honored Contributor

Re: Connecting Autoloaders in Daisy Chain

Hello,

Although it MIGHT work if both 1/8 and 24x6 are SE, it is not supported to daisy-chain two autoloaders.

Now I guess you are asking whether you can daisy-chain hese 2 autoloaders, together with the Array 5300? It's asking too much I think.

vs80 technology is only LVD. If you daisy-chain both autoloaders and vs80, your vs80 will work in SE mode, which will render it slow. Backups might fail if vs80 works in SE mode.

Well, you can try it if your DLT7000 1/8 is SE. It can work. Some precautions though if you want to try this: do NOT start backups simultaneously on more than 1 drive at a time. Make sure you don't have SCSI conflicts (both autoloaders take up 2 SCSI IDs + vs80 drive = 5 SCSI IDs). 5 things on the same chain is definetely not supported and you will be asking for trouble. SCSI bus won't keep up with all 5 devices at all times, you might (or I can say WILL) see problems.

HTH,
Vince
Tape Drives RULE!!!
Sachin Sontakke
Occasional Contributor

Re: Connecting Autoloaders in Daisy Chain

Thanks a lot for your help.

Here I am giving what I found a bit.

Can I configure my 1/8 and 24x6e autoloaders in daisy chain?

I am not concerned about Tape Array 5300. This tape array, like Malvin said , is LVD/SE scsi device.

Cable coming from the Tape drive in it is going to Slot 10. I checked both sides of these connections and found that connector on Tape is wide and connector on Slot 10 on HBA is narrow/slick one(Cable is same although).

For Slot 10 just on top there is one empty slot for scsi connector (of same size as given for tape drive in array 5300 {VS80 tape drive}) . I was planning to hook up my one of autoloader there and conncet remaining one in daisy chain with it. But I checked cable connectors for 1/8 and they were wide in size on both ends.

My 24x6e is a DDS-3 external autoloader. cable/Connector for that one is again totally different.

It seems I need a new 1/8 autoloader as shown on HP site to hook it up with this server. My 1/8 looks old one. It is not wide and across. It is a long one and also narrow in shape. Plus cable terminators/connectors are not matching here.

Please suggest me on this.

- Sachin
Sachin Sontakke
Occasional Contributor

Re: Connecting Autoloaders in Daisy Chain

I forgot to add that my 1/8 7000 is differential; that's what sticker on back panel says.

Thanks,

Sachin
malvin drakley
Esteemed Contributor

Re: Connecting Autoloaders in Daisy Chain

Hi Sachin again, could you give us the model numbers of the 2 autoloaders please, and that will help us to determine the interface you need
thanks
malvin
Not me Chief, I'm Radar
Alexander M. Ermes
Honored Contributor

Re: Connecting Autoloaders in Daisy Chain

Hi there.
If your DLT7000 1/8 is differential,
you need a FWD controler ( HVD ).
For pc's it is an Adaptec 2944.

This is my output from ioscan on my V2500 for the DLT7000 controlers :

ext_bus 0 0/0/0 c720 CLAIMED INTERFACE SCSI C875 Fast Wide Differential.

Try an 'ioscan > /var/tmp/ioscan.txt' to find out about the interfaces and drives.

Or check it with the Support Tool Manager.

Rgds
Alexander M. Ermes
.. and all these memories are going to vanish like tears in the rain! final words from Rutger Hauer in "Blade Runner"
Alexander M. Ermes
Honored Contributor

Re: Connecting Autoloaders in Daisy Chain

By the way :

Forget the daisy chaining. That will kill your performance and extend the length of your SCSI bus to more than maximum.
For HVD max length was something about 6 meters ( interface takes 1m, every device takes about half a meter AFAIK ).

It will cause trouble as ha been said in replies before.

Rgds
Alexander M. Ermes
.. and all these memories are going to vanish like tears in the rain! final words from Rutger Hauer in "Blade Runner"
Scott McIntosh_2
Honored Contributor

Re: Connecting Autoloaders in Daisy Chain

You have:

Fast Wide HVD DLT autoloader
Fast(?) Narrow SE DDS autoloader

Different width and different signaling. Put them on different SCSI busses.

The single-port Ultra Wide HVD card for the L-class is the A4800A.

The single-port Ultra2 Wide LVD/SE card for the L-class is the A5149A.

I assume the 5300 is already hanging off the core I/O Ultra2 port at the bottom.

I don't know much about hooking up narrow devices to a wide controller, but I assume there are 68-pin to 50-pin cables which just leave the other 18 pins hanging.

Thanks,
Scott
HP Support