T. Horsnell wrote: ...
When I put the lib back onto the Alpha, two test files (tapetest500K and tapetest50M) written on the Opteron and read back on the Alpha, matched the files as read back on the Opteron. This convinces me that its (at least) a 'write' problem.
Is it just the library you move, or can you also try to move the SCSI controller and cables?
I just move the library, but I've swapped cables as well. I also contacted the author of the st driver and he reckons I should try a different sort of SCSI adapter. I'm coming to the same conclusion, but perhaps I'll try the author of the aic79xx driver first, since I'll have to buy an adapter in order to try things.
I found A PC running FC3 (kernel 2.6.10-1.741_FC3) which had an Adaptec 29160 SCSI adapter in a 32-bit PCI slot. I connected my SDLT2 library to it and repeated my tests. Everything worked!.
Adaptec 39320 uses aic79xx driver Adaptec 29160 uses aic7xxx driver
I took the 29160 out of the PC, intalled it in the Opteron box (into a 64-bit PCI-X slot) and repeated the tests. Failure. The Opteron has 4 kernels available: 2.6.10-1.770_FC3smp 2.6.10-1.770_FC3smp 2.6.10-1.770_FC3 2.6.10-1.770_FC3 I tried them all. Failure. I even booted from a Knoppix CD with 2.4.27. (This presumably means I'm running a 32-bit kernel on a 64-bit box). Failure.
I remembered I had a desktop Compaq SDLT1 tapedrive on one of my systems. I tried that on the 29160 adapter. Success. I tried it on the 39320 adapter. Success. Is it some sort of datarate problem I ask myself (the SDLT1 is about half the speed of the SDL2) and the SDLT2 worked on the PC. I moved the 2960 out of the PCI-X slot into a PCI slot and tried again with the 5 Kernels listed above. Failure.
I'm now running out of ideas/energy/hardware. With my original configuration, (Opteron, 2.6.10-1.770_FC3smp, Adaptec 39320, dual SDLT2) I can get verified tar dumps of at least 4GB (I havent tried anything bigger) provided I use a record size > 32768 (64*512). 65536 (256*512) works fine, as does 131072 (256*512). 32768 fails.
Is it time to file a bug report? Who with?
Thanks for any and all suggestions,
Terry.