Thanks to everyone who responded for this question dilemma.

Received several responses that their filer showed "Differential", while other showed "Single-ened". My thoughts on this: not all F760s are the same!

One interesting response stated that after a motherboard RMA, a filer which used to show "Single-ended" (after the RMA motherboard change) now shows "Differential". NOTE: this site did not use the SCSI port for any external connections so was never tested against any devices. My thoughts on this: more a question. does NetApp ship F760s with different on-board SCSI controllers? ... Read on!

One response reported that their filer, which reported "Single-ended", was attached and would not work with a differential device. But worked after the purchase of a QLA-1040B HVDiff card (for the Netapp F760).

Another response stated that when they upgraded their filer from OnTap 6.2.X to 6.4.2P6 ... the output went from "Differential" to "Single-ended" My thoughts on this: well well .. I don't think the hardware changed ... maybe the Netapp software folks are making sure the end-users are paying attention. So there is possibility that the F760 SCSI is differential SCSI as I was told ... but the software just is not reporting correctly.

Maybe the definitive response was from a netapp.com email response: "This is a cosmetic bug (89928) introduced in ONTAP 6.4. Your onboard scsi is still Fast/Wide Differential, but the sysconfig is displaying it incorrectly." I could not find the bug number referenced when I searched at NOW.

And lastly ... my problem, the "downed" tape drive (which initiated this post), was operator error ... I opened the tape library and looked very closely with a flash light this time, and noticed that the DLT7000 handle was in the wrong position ... duh!!! ... and now Veritas sees both attached differential drives and they are no longer downed by the Veritas backup software.

My conclusion: I believe I have a differential external SCSI controller on my F760 but that "sysconfig -v" incorrectly reports the SCSI as being "Single-ended".

Hope this helps someone else in the future

Harold White Covaro Networks

Harold White wrote:

Greetings,

I just noticed that my F760 displays, what I believe to be, its on-board external SCSI port as "Fast/Wide, Single-ended"

F760> sysconfig -v NetApp Release 6.4R1: Thu Mar 13 22:59:45 PST 2003 .... slot 0: SCSI Host Adapter 0b (Qlogic ISP 1040B, <ONLINE>) Fast/Wide, Single-ended Firmware Version 4.66.00 Clock Rate 60MHz. 4: Tape: Quantum DLT7000 245F 5: Tape: Quantum DLT7000 245F .....

I am/was under the impression that it was a Fast/Wide Differential (on-board) SCSI controller.

I have 2 DLT7000 drives connected to the Filer ... and they are absolutely differential (2 drives from a Sun L1000).

My Veritas Datacenter software keeps down'ing one of my drives and I have just ignored it due to time constraints plus the fact that I had/have one good drive still working. But now that I am trying to troubleshoot the problem, I do not know if the problem is that I have been lucky that a "Single-ended" filer controller has been providing me good backups to my differential (one) tape drive? (Is that even supposed to work at all?)

Can anyone confirm that the output (sysconfig -v) of a F760 "Single-ended" is correct or incorrect? That is, is the on-board external SCSI port a differential or single-ended SCSI port and the "sysconfig -v" message is right or wrong?

Regards, Harold White Covaro Networks