mbrookov@diana.cair.du.edu (Matthew B. Brookover) (04/04/91)
We reacently purchased an 8mm tape drive from Micro Technology. The drive seems to mess up the last part of some of the files written to the tape. usually the last carrage return gets dropped or replaced by garbage. Some times the last 2 or 3 lines of a file are appended to the last line, duplicating them. The drive is on a DEC System 5400 running Ultrix 4.1. The 8mm tape drive is attached to the q-bus by a QTS30 controller, also from Micro Technology. The sales person told us that the controller emulates a TK50, but at boot time the kernel says the drive is a TU81. Here is a little test shell script: #!/bin/sh date echo summing file1: sum file1 dd if=file1 of=/dev/rmt1h bs=10k echo dd if=/dev/rmt1h to create file2 dd if=/dev/rmt1h bs=10k > file2 echo diffing file1 and file2 diff file1 file2 echo summing file2: sum file2 date I copied /etc/passwd to file1 and ran the above shell script, here is it's output: Wed Apr 3 07:53:03 MST 1991 summing file1: 37647 160 15+1 records in 15+1 records out dd if=/dev/rmt1h to create file2 16+0 records in 16+0 records out diffing file1 and file2 2064c2064,2065 < sbasu:xxxxxxxxxxxxx:8122:8122:SOMNATH BASU:/u/finance/sbasu:/bin/csh --- > sbasu:xxxxxxxxxxxxx:8122:8122:SOMNATH BASU:/u/finance/sbasu:/bin/csh:/bin/csh > lruth:xxxxxxxxxxxxx:10553:10553:LAURENCE P. RUTH:/u/realest/lruth:/bin/csh summing file2: 21271 160 Wed Apr 3 07:55:14 MST 1991 Here is the last 5 lines of file1: agridley:xxxxxxxxxxxxx:10726:10726:ADAM D. GRIDLEY:/u/ugrad/agridley:/bin/csh dacox:xxxxxxxxxxxxx:10702:10702:DARYL E. COX:/u/uc/dacox:/bin/csh mhammer:xxxxxxxxxxxxx:10739:10739:MARC B. HAMMER:/u/ugrad/mhammer:/bin/csh ptrick:xxxxxxxxxxxxx:10741:10741:PETRA A. TRICK:/u/finance/ptrick:/bin/csh sbasu:xxxxxxxxxxxxx:8122:8122:SOMNATH BASU:/u/finance/sbasu:/bin/csh and here is the last 5 lines of file2: mhammer:xxxxxxxxxxxxx:10739:10739:MARC B. HAMMER:/u/ugrad/mhammer:/bin/csh ptrick:xxxxxxxxxxxxx:10741:10741:PETRA A. TRICK:/u/finance/ptrick:/bin/csh sbasu:xxxxxxxxxxxxx:8122:8122:SOMNATH BASU:/u/finance/sbasu:/bin/csh:/bin/csh lruth:xxxxxxxxxxxxx:10553:10553:LAURENCE P. RUTH:/u/realest/lruth:/bin/csh tschramm:xxxxxxxxxxxxx:10554: as you can see, the tape drive did not accuratly record the data. I also copied /usr/dict/words to file1 and ran the shell script to get: Wed Apr 3 07:46:14 MST 1991 summing file1: 52793 197 19+1 records in 19+1 records out dd if=/dev/rmt1h to create file2 19+1 records in 19+1 records out diffing file1 and file2 24474d24473 < Zurich summing file2: 52888 197 Wed Apr 3 07:48:19 MST 1991 /usr/dict/words came through ok, but the carrage return on the last line was eaten. The problem is not always consistant either. I typed this string into a file: abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890!@#$%^&*()_+ and duplicated it 1000 times. and then ran the test shell script: Wed Apr 3 07:48:56 MST 1991 summing file1: 30266 74 7+1 records in 7+1 records out dd if=/dev/rmt1h to create file2 7+1 records in 7+1 records out diffing file1 and file2 summing file2: 30266 74 Wed Apr 3 07:50:58 MST 1991 It worked perfectly. The same tests on a TK70 tape drive on the same 5400 run perfectly. We installed the tape drive over a month ago, we had a number of problems with the installation. after some mucking around we got those resolved and discoverd that mt would not always work. The Micro Technology tech support people said to was because we were running Ultrix 3.1C. upgrading to Ultrix 4.1 seems to have fixed the mt problem and created the end of file problem. Has anybody out there had any similar problems with 8mm tape drives and Ultrix? does anybody else have an 8mm tape drive on a 5400? The Micro Technology people are looking into the problem, but they are moving very slowly, and I need answers soon. I have had the tape drive for almost 2 months now, and it has never worked properly. thanks. -- Matthew B. Brookover Computing and Information Resources University of Denver mbrookov@diana.cair.du.edu
GEOMAGIC@kcgl1.eng.ohio-state.edu (Daniel OConnell) (04/04/91)
We have a DEC5400 running Ultrix 4.1. We have a TK70, 9-track Cipher 990 on a Dialog Pertec controller, and an 8200 Exebyte on a CMD 220 controller. Prior to installing Ultrix 4.1 we could read variable record size tapes. Now, we get truncated record errors on the 9-track and cannot read more than 2 records from tapes we could read under Ultrix 3.1C. This problem affects all the tape drives, including the TK70. DEC replaced the TK70 and we still have the same problem. Also, now the cache command (MTCACHE) no longer works with the Cipher 9-track. What gives? Has anybody else experienced problems with dd, variable record length tapes, and Ultrix 4.1? Has the TMSCP driver been damaged? We removed the Exebyte and CMD controller to mimic our Ultrix 3.1C configuration and still have the same problems. When our DEC maintenance person called DEC support they told him the tapex tape exercise utility is useless... Dan O'Connell geomagic@geo1s.mps.ohio-state.edu