jlavi@ujocs.joensuu.fi (Jarkko Lavinen) (01/29/91)
I've been trying to do a remote dump from older 3/50 (SunOS 3.5) to a SparcStation 1+. I've had no problem at all with doing local dumps on Sparcstation (SunOS 4.1) like : (tape device is 150MB, 18 tracks, density 1200 BPI) /etc/dump 0ucsdtbf 590 1200 18 126 /dev/rst0 /dev/sd0g No problem at all. The parameters are caught from the manual. Then I tried to do a remote dump from the 3/50. The older dumps doesn't know what a track is, and it thinks the tape as a one-track device. Thus the length (or density) has to recalculted to compensate. The man page says (length*tracks)*0.9. So I made the calculation and tried this /etc/rdump 0nucsdbf 9700 1200 126 remotehost:/dev/rst0 /dev/sd1c Well, this causes write error after about hour of dumping. The tape simply ends. It seems dump can't calculate it's tape usage properly. One of the reason I've been think is record gap. Dump probably expects record gap to be 1/18 of the real value, because the same gap is probably at the same time and place on all tracks. I tried to reduce the length by 10%, but it didn't help. After that I reduced some >50% and dump went ok. I could probably estimate the correct tape length by some kind of binary search, but it doesn't quite feel elegant way to do it. Can anybody out there say how the correct tape length is calculated? I would be very thankful for comments on this. Jarkko Lavinen