Multiple SAS 1760's in an HP 1U rackmount Chassis

[Robert1969]

Hello,

We have the 1U Rackmount chassis with 2 of the 1760 LTO54 drives. We are having problems with the drives when we perform backups. One of the 2 drives will consistently write errors, truncated files, out of sequence blocks, etc...

We have done a lot of trouble shooting and this is the results:

1. Inside the 1U chassis is an SAS/SATA cable that connects from the internal 'SAS expander Board' to the back of each drive. If we unplug the data cable from the right drive and connect to the left and vise versa, the data errors follow the cable.

2. If we do the same with the 2 external mini SAS 8088 to 8088 cables that connect the 1U chassis to the computer SAS controller card, the errors do not follow the cable switch.

3. We are using BRU backup software. They state that the problem is in the 'file system' and their software is not causing the problem.

I have seen another post here:

http://forums13.itrc.hp.com/service/forums/questionanswer.do?threadId=1447800&sortPointsFlag=1

Here, someone has responded that there was a customer advisory about the SAS interval expander boards. So could this problem be hardware or OS, or other...? Anyone have any experience with this?



Robert

[Sudhakar Subramaniam]

Hi,
You can use the below documents for connection.


HP StorageWorks LTO-4 Ultrium 1760 Tape Drive - Installing an External Ultrium Tape Drive by Connecting to an External SAS Port


http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&taskId=115&prodSeriesId=3663381&prodTypeId=12169&objectID=c01434273

HP StorageWorks LTO-4 Ultrium 1760 Tape Drive - Installing an External Ultrium Tape Drive by Connecting to an Internal SAS Port

http://bizsupport1.austin.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c01434267&printver=true

[Robert1969]

Thank you for the reply, however connecting the hardware is not an issue. We have been using this setup for 8 months now.

We are getting errors reported during the verify of some LTO tapes from one drive. How to connect the hardware is not what is being asked.

[Zygmunt Krawczyk]

Read this customer advisory

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c01661178〈=en&cc=us&taskId=101&prodSeriesId=434185&prodTypeId=12169

Which model of HBA do you have?

[Robert1969]

Sorry for the late response... It is an ATTO H380 SAS card.

I have recently even changed the server to another server and found that the errors are the same. So it seems the problem is outside the computer.

I am quite sure that the problem is not the drives themselves.

I am deeply suspecting the small 'SAS Expander Bd.' inside the 1U rack... Anyone with any thoughts?