nagy%43198.hepnet@LBL.ARPA.UUCP (03/30/87)
FNAL has a very large VAXCluster with several large 8xxx systems and 12 TA78 tape drives (3 formatters each with 4 drives). Each HSC50 has a single K.STI card; one HSC50 supports 2 formatters and the other only a single formatter. The K.STIs are at microcode level 26 and the TM78 formatter is at Rev 4. The tape subsystems are in heavy use from user processes (i.e., not just BACKUP). We are experiencing formatter hangs which require a formatter be reset (rewinds all the tapes connected to that formatter) on the order of about once per week (over all 3 formatters). Is anyone else in netland experiencing this problem? Is anyone not experiencing this problem and yet making heavy non-BACKUP usage of their TA78 subsystems?
SYSTEM@CRNLNS.BITNET.UUCP (03/31/87)
Frank, We have been having exactly the same problem. Our local DEC office has been unable to resolve it. Given the infrequency of the failure on our cluster (once or twice a month) it is really hard to track down. Our configuration is smaller of course: 2 8600s, 1 HSC50, 3 TA78s (1 formatter), 10 RA81s. My personal belief is that the controller can't recover from certain types of tape data errors, and just gives up. The TU78s may be having the same problem with long record lengths that we (FNAL and CLNS) have been seeing with streaming tape drives. You didn't mention what revision of HSC code you are running. Although all of our hardware is up to current rev., we have not yet upgraded our HSC50 sofware from 2.50 to 3.00, since it means rearranging the channel cards and several hours of downtime for the whole cluster. We now take data and do our analysis using Massbus TU72s (STC 3650s). They are much more reliable than TU78s, and have no problems whatsoever with 28kilobyte records. I hope that this can be resolved, however. Selden E. Ball, Jr. (Wilson Lab's network and system manager) Cornell University NYNEX: +1-607-255-0688 Laboratory of Nuclear Studies BITNET: SYSTEM@CRNLNS Wilson Synchrotron Lab ARPA: SYSTEM%CRNLNS.BITNET@WISCVM.WISC.EDU Judd Falls & Dryden Road PHYSnet/HEPnet/SPAN: Ithaca, NY, USA 14853 LNS61::SYSTEM = 44283::SYSTEM (node 43.251)