Dan, Dave, Jim:

WP 5333

A reminder, just before ER7 Dan found data errors between a Q-Logic fiber-channel switch in the MSR and its corresponding machine in the LDAS server room. The error started after the tape robobt was moved from the CUR to the VPW and its data was added to the DAQ switches. We tried repacing fiber optic cables (did not help), and then Dan purchased new SFPs for both ends of the long haul. In the mean time for ER7 we effectively bypassed the defective switch, sending all the data through a second switch in the MSR. In order to do this, a short multimode fiber link was made between the MSR switches. End of history lesson.

Today Dan reactived the original single mode link and deactivated the multimode inter-switch link. Within the next hour fw0 crashed twice, so unfortunately it does not look like the single mode SFPs were the problem. We have gone back to the ER7 configuration.