johan@dutnak2..tudelft.nl (Johan de Haas) (08/10/90)
We have an Exabyte connected to a DECstation 3100. Every now and then we want to connect it to another machine. BUT, we don't want to shut down the DEC, since it acts as a cheap fileserver for a lot of users. We are not sure if we can safely do this. Anyone on the net doing it all the time? -- Johan de Haas tel. +31 15 785188 E-mail: johan@dutnak0.tudelft.nl Delft University of Technology P.O Box 5046, 2600 GA Delft, The Netherlands -- Johan de Haas tel. +31 15 785188 E-mail: johan@dutnak0.tudelft.nl Delft University of Technology P.O Box 5046, 2600 GA Delft, The Netherlands
lancelot@spock.UUCP (Thor Lancelot Simon) (08/11/90)
We swap TK50s around all the time here - it works fine as long as the machine you are putting it on had a tape on it at boot time or it won't be recognized. ******************************************************************************* *Thor Simon * Okay, just a little pin-prick...There'll be no more-* *lancelot@spock.UUCP * Aieeeeaaaugh!-but you may feel a little _sick_. * *uunet!hsi!yale!lancelot* ---Pink Floyd *
grr@cbmvax.commodore.com (George Robbins) (08/11/90)
In article <johan.650293716@dutnak2> johan@dutnak2..tudelft.nl (Johan de Haas) writes: > We have an Exabyte connected to a DECstation 3100. Every now and then > we want to connect it to another machine. BUT, we don't want to shut > down the DEC, since it acts as a cheap fileserver for a lot of users. > > We are not sure if we can safely do this. If the SCSI bus is active, with disks and things running, you stand a real good chance of trashing disk transfers in progress. Also, SCSI isn't set up for "hot" connection/disconnection, no protection for the drivers or receivers so you'd probably zap something fairly quickly unless you power down both sides. > Anyone on the net doing it all the time? Probably. 8-) -- George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr but no way officially representing: domain: grr@cbmvax.commodore.com Commodore, Engineering Department phone: 215-431-9349 (only by moonlite)
nraoaoc@nmt.edu (NRAO Array Operations Center) (08/11/90)
In article <1990Aug10.173348.4125@spock.UUCP> lancelot@spock.UUCP (Thor Lancelot Simon) writes: >We swap TK50s around all the time here - it works fine as long as the machine >you are putting it on had a tape on it at boot time or it won't be recognized. I didn't think TK50's were SCSI devices, though I don't know about on 3100's. What you describe sounds awfully like the way VMS treats them. On Suns I have found that you *can* disconnect SCSI devices so long as: a) nobody tries to access any SCSI device on the bus while you are working, b) you have an easy way of moving the terminator if necessary The second point is important, since you don't want to leave the SCSI bus unterminated. External or inline terminators make this easy, or if the device to be removed is in the middle of a daisy chain. If the disks your system serves are SCSI, though, forget it. The only way you can guarantee point a) is to unexport them all, in which case you might as well just shut the system down anyway. Disclaimer: no promises, it has worked for me. -- Ruth Milner Systems Manager NRAO/VLA Socorro NM rmilner@zia.aoc.nrao.edu
jg@crl.dec.com (Jim Gettys) (08/13/90)
>>We swap TK50s around all the time here - it works fine as long as the machine >>you are putting it on had a tape on it at boot time or it won't be recognized. >I didn't think TK50's were SCSI devices, though I don't know about on 3100's. >What you describe sounds awfully like the way VMS treats them. TK50Z's are SCSI devices; they are used with VS3100's, DS2100's, DS3100's and DS5000's (and probably whatever else you want to plug it into that supports SCSI). Vanilla TK50's (which plug into VS2000's and some of the Microvaxen) aren't quite SCSI (before we'd learned to do it right... Sigh...). - Jim