dan@asihub.autosys.com (Dan O'Neill) (12/08/90)
Hardware: Sun Sparc 1+ (4/65)
OS: 4.1
Disks: 1.2mb CDC
Tape: WangDAT
I am looking for information regarding the usage of a WangDAT drive on a
Sun system. We've been experimenting with the tape drive and have been
experiencing back times like:
4.7hrs to backup 500mb using dump with the following parameters
"dump 5ubdfs 4096 488000 /dev/rst0 200 /filesys"
This time is really not reasonable for this type of tape device. Does
anybody have any experience with this tape unit? Are there some internal
buffers in the kernel which must be altered to support 4mm tape units?
Any and all answers/speculation will be appreciated.
Dan O'Neill Cadence Design Systems
dan@autosys.com San Diego, CA
{uunet|ncr-sd}!asihub!danhd@relay.eu.net (Hans Dietrich) (12/12/90)
In article <637@brchh104.bnr.ca> dan@asihub.autosys.com (Dan O'Neill) writes: >I am looking for information regarding the usage of a WangDAT drive on a >Sun system. We've been experimenting with the tape drive and have been >experiencing back times like: > >4.7hrs to backup 500mb using dump with the following parameters >"dump 5ubdfs 4096 488000 /dev/rst0 200 /filesys" I had the same problem with the above mentioned configuration a while ago. By default the WangDAT isn't among the st-devices which the kernel knows about. So it uses some default values which are leading to the bad results in backup time. To get a fast backup you have to modify the file "st_conf.c" under "/usr/kvm/sys/scsi/targets": 1. Search for the entry for the Exabyte 8mm cartridge 2. duplicate it [ 3. change the comment (e.g. WangDAT 4mm cartridge) ] 4. change the line "Exabyte", 7, "EXABYTE", ST_TYPE_EXABYTE, 1024, to "Wangdat", 7, "WangDAT", ST_TYPE_EXABYTE, 1024, Now recompile the kernel, install it, reboot and have fun! (The dump command I use is: dump 0acbdfsu /etc/dumpfiles.1h0 126 27000 /dev/nrst1 6000 /dev/rsd1h) Hans Dietrich Voice: +49 (2101) 44 05-50 X Computer Consult GmbH Fax: +49 (2102) 44 05-66 D-4030 Ratingen Mail: dietrich@xcc.de Brandenburgerstr. 2