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Can a single SC44Ge HBA be cabled to two 1760 SAS tapes in a 1U enclosure?

 
Paul_637
Regular Advisor

Can a single SC44Ge HBA be cabled to two 1760 SAS tapes in a 1U enclosure?

I know of a server with an HP SC44Ge controller with a 1-to-4 cable with two of them connected to two drives in an MSL4048.

Can such a cable (or a similar one) connect a single SC44Ge to a pair of 1760 SAS tape drives or would I need a second SC44Ge?

Thanks in advance,

Paul
10 REPLIES 10
Marino Meloni_1
Honored Contributor

Re: Can a single SC44Ge HBA be cabled to two 1760 SAS tapes in a 1U enclosure?

http://h18006.www1.hp.com/products/quickspecs/13258_div/13258_div.html

it indicate that you may have the sc44Ge as an HBA, having the SFF8470 connector

you should be able to use the AH587A cable kit to connect it to the MSL (2m External Infiniband (SFF8470) to 4 Mini SAS (SFF8088) 1x SAS Cable Kit
NOTE: One cable is required for every four drives. Use this cable to connect HP StorageWorks MSL SAS Tape Libraries to HP SAS controllers with Infiniband (SFF8470) connectors. AH587A)
Paul_637
Regular Advisor

Re: Can a single SC44Ge HBA be cabled to two 1760 SAS tapes in a 1U enclosure?

Apologies, perhaps I wasn't quite clear.

We already have such a connection to the MSL, what I now want to know is can we use a similar cable to connect a singl SC44Ge to two LTO-1760 SAS drives mounted in a 1U rack-mount kit (or even to two external LTO-1760 SAS drives).

(I was merely refering to the MSL as an example to describe the type of cable).
Marino Meloni_1
Honored Contributor

Re: Can a single SC44Ge HBA be cabled to two 1760 SAS tapes in a 1U enclosure?

I do not see any difference between connecting two devices in a MSL or two stand alone device if the connector is the same
so for me it is yes
Paul_637
Regular Advisor

Re: Can a single SC44Ge HBA be cabled to two 1760 SAS tapes in a 1U enclosure?

That's what I thought but then I'd like things to be simple wouldn't I? :)

The thing I was cautious of was the reference to "Infiniband" and "mini-sas".

The MSL drive is about 120 miles away from me otherwise I'd go have a look at the remaining cables to see if they're the same as the "standard" SAS cables I have around here!
Marino Meloni_1
Honored Contributor

Re: Can a single SC44Ge HBA be cabled to two 1760 SAS tapes in a 1U enclosure?

I like google

http://en.wikipedia.org/wiki/File:SFF_8470.jpg
http://en.wikipedia.org/wiki/File:SFF_8088.jpg

these are the connectors, now if you have your stand alone sas drive, you should be able to match it or not
Curtis Ballard
Honored Contributor

Re: Can a single SC44Ge HBA be cabled to two 1760 SAS tapes in a 1U enclosure?

Yes you can use the same cable. If you have a 1U rack enclosure with an LTO-5 drive then the cables used with the MSL are qualified for use with that enclosure. The cables were never qualified for use with the previous model enclosure which has a different SAS interface card however the cable used with the MSL is very closely related to the 4m cable that was qualified with that enclosure and I wouldn't expect any issues.

Check the quickspecs for the most recent rack mount enclosure for cable details:
http://h18000.www1.hp.com/products/quickspecs/10854_na/10854_na.HTML

For the SC44Ge the only cable that allows connection of multiple tape drives is the 2m AN975A.
Paul_637
Regular Advisor

Re: Can a single SC44Ge HBA be cabled to two 1760 SAS tapes in a 1U enclosure?

Many thanks for the additional info Curtis but it does muddy the water for me a little.

I can definitely say that the 1U rackmount kits I ave *didn't* come with an LTO-5 drive. Does that then definitely mean that the 1U kit I have won't work with one of these cables?

At least I can now round it down to just the cable you've specified as being the only one compatible with the SC44Ge which is useful in itself, all I need to do now is figure out which 1U kit I have.

I took a quick look at one I have on site here but the labelling is on the underside of the unit so rather difficult to grab a part number from without removing from the rack.
Paul_637
Regular Advisor

Re: Can a single SC44Ge HBA be cabled to two 1760 SAS tapes in a 1U enclosure?

I just managed to get a closer look at the 1U kit I have here and it has a part number of EH946A whereas the 1U kit in your link seems to be EH946B.

Assuming the one I have on the other site is also an EH946A, would that then definitely mean I can't use the AN975A cable with what I have?

If so, can anyone suggest what I might need as an alternative to connect a second SAS tape drive to a DL380 G5 that will already have 2 x FC and 1 x SC44Ge cards installed in slots 3, 4 & 5, i.e. it'd need to be "half-height" and fit in slot 2, slot 1 being taken by a P400.
Curtis Ballard
Honored Contributor

Re: Can a single SC44Ge HBA be cabled to two 1760 SAS tapes in a 1U enclosure?

The "A" vs "B" part number means that you have the early version of the enclosure and HP has not tested or qualified the multi-drop SAS cable with that enclosure. The multi-drop cable did not exist when that enclosure was released but it was designed using the cable that is recommend for use with the controller as the design basis.

Because that cable is based on the recommended cable it should work fine but because the multi-drop cable didn't exist when that enclosure was developed/tested it is not officially supported.

I have used that multi-drop cable with the exact same model enclosure for a quick experimental test and there are no obvious issues. I can't run a full qual cycle with that older enclosure.

There are several revisions of the SAS interface card in the enclosure you have. I would recommend checking that before purchasing a cable. The boards I have say rev 0E. You have to at least take the top cover off to read the label on the SAS interface card.