Hi all, I wonder if I could ask your advice about a very strange SCSI tape problem I'm having. I have an Overland Neo2000 tapelibrary containing dual Quantum SDLT2 drives, attached to a dual Opteron box via an Adaptec 3920 controller. The system is running FC3 up2date'd on April 6th and with kernel 2.6.10-1.770_FC3smp. The problem appears to be that the tapes drop records when being written, but that this can be fixed by increasing the blocksize. I have a bunch of test files filled with random numbers: e.g. -rw-r--r-- 1 root root 500000 Apr 26 11:03 tapetest500K -rw-r--r-- 1 root root 1000000000 Apr 26 12:48 /var/tapetest1G When I write these to tape and read them back, I get things like the following: [root@ls1 ~]$ dd if=tapetest500K of=/dev/st1 bs=10240 ; dd if=/dev/st1 of=junk bs=10240 ; cmp tapetest500K junk 48+1 records in 48+1 records out 36+1 records in 36+1 records out tapetest500K junk differ: byte 215041, line 854 [root@ls1 ~]$ dd if=tapetest500K of=/dev/st1 bs=20480 ; dd if=/dev/st1 of=junk bs=20480 ; cmp tapetest500K junk 24+1 records in 24+1 records out 24+1 records in 24+1 records out [root@ls1 ~]$ ( cd /var ; dd if=tapetest1G of=/dev/st1 bs=10240 ; dd if=/dev/st1 of=junk bs=10240 ; cmp tapetest1G junk ) 97656+1 records in 97656+1 records out 90107+1 records in 90107+1 records out tapetest1G junk differ: byte 215041, line 866 [root@ls1 ~]$ ( cd /var ; dd if=tapetest1G of=/dev/st1 bs=20480 ; dd if=/dev/st1 of=junk bs=20480 ; cmp tapetest1G junk ) 48828+1 records in 48828+1 records out 48801+1 records in 48801+1 records out tapetest1G junk differ: byte 2621441, line 10186 [root@ls1 ~]$ (cd /var ; dd if=tapetest1G of=/dev/st1 bs=32768 ; dd if=/dev/st1 of=junk bs=32768 ; cmp tapetest1G junk) 30517+1 records in 30517+1 records out 30517+1 records in 30517+1 records out [root@ls1 ~]$ The problem happens on both tapedrives. No errors are logged in /var/log/messages. The Neo2000 system performs faultlessly when attached to my Alpha box. Does this look to you like a hardware problem? Or could it be a driver issue? Unfortunately I dont have enough spare kit to try things on another box. Regards, Terry
