I am facing problem with my Tape drive \(hp\) \(/dev/rct0\) on SCO Unix version 6.0.0. Sometimes tar works fine but some times it doesnot work and I have to restart the server to get it work. One reboot/shutdown is OK. to solve the problem. Error is "cannot open /dev/rct0" though the tape is recognised \(ls /dev/rct0 is there\). Same tape drive is Ok at one time and other time this problem is there.
Powering ON/OFF tape device is of no help
This is not the issue of tapes
My thinking is that this is NOT a software issue. This sounds like a subtle hardware issue.
I assume this tape drive is a SCSI device.
Try shutting down and unplugging/replugging the SCSI cable, perhaps also take out and reseat the SCSI adapter itself. Also, check the SCSI terminations.
Also, replug the power supply to the tape drive.
Has this problem suddenly occured after working fine for some time?
My experience was 4.2 and 5.0 with tape drives and your symptoms are of a tape drive going bad. At some point before you needed it to work it lost ready and can only get it back on a reboot.
Yes, I agree but, adding to my previous post, the reboot gets the SCSI adapter to issue a SCSI reset to the tape drive and it appears that this is enough to make it work. Therefore, SCSI communication is most likely the issue hence my comment about re-seating the cables, etc.
You didn't answer my question as to whether this has ever worked or simply stopped working. Also what type of tape drive it is.
Another thought is that, if it is a DAT drive, these usually have a 8 pole DIP switch underneath which if set incorrectly (for this hardware and O/S) might cause this type of behaviour.
<You didn't answer my question as to whether this has ever worked or simply stopped working.>
As I said , this works fine sometimes and sometimes it don't work and shows "cannot open /dev/rct0" \(tape OK.\) .This is not the new tape drive we are using, it has been here working fine , without this fault, from last 3 yrs.
I support SCO boxes for a living and have found in most cases that it is a break in the SCSI communication. if you run tape status it will return an error unless there is a tape currently unloading or loading. No other commands such as tape status or tape rewind/unload,. etc wil work. I find I can usually clean the dust bunnies out and reseat the cable andcard which will fix the issue for quite awhile. Eventually thou you will need another tape drive. I have rarely found a bad SCSI card...
Thanks for sharing your experiences. I cleaned off the cable and connectors , and reassembled them. Then a tape reset, rewind command and the problem is almost gone.
2 Days Ago