John_Mansfield@emal.sprl.umich.edu (John F. Mansfield) (12/21/90)
In article <2472@sparko.gwu.edu>, waire@seas.gwu.edu (Timothy A. Waire) writes: > What is the problem with this product? Does anyone else in the world have > these problems with this product? Help!! I have had no experience with the Nodem, however one of the publications did a review of Nodems, Ether+ and the NuvolinkSC. They (MacWorld or MacWeek) said that there wasnt much in it, but they would choose the Ether+ over the Nodem and the Nuvolink was the same animal as the Ether+ in a different box. Now, some people I know have had harsh words to say about Compatible Systems, but I bought an Ether+ and have had no trouble with it. We use it for Ethertalk and for TCP/IP and although it can be slow, it is better than LocalTalk, mainly because then we dont have to rely on one of those Fastpath monstrosities (MY opinion, not the U's). There is a problem with these SCSI ethernet devices and CE Software's Quickmail, at some point, if you use the SCSI ehternet box on the MailServer, both the SCSI box and the QM Server try and grab the same interupt and the Mac hangs. This explanation was offered by CE and they do not have a work around. Compatible Systems did send me new software recently, but since I have moved the MailServer to a modular Mac with ethernet card I havent bothered trying to see if the freezes are less common with the new stuff. Just my 2 cents worth. John Mansfield.
korn@eris.berkeley.edu (Peter "Arrgh" Korn) (12/24/90)
In <1990Dec21.144218.17923@engin.umich.edu>, John_Mansfield@emal.sprl.umich.edu (John F. Mansfield) said: >I have had no experience with the Nodem, however one of the publications >did a review of Nodems, Ether+ and the NuvolinkSC. They (MacWorld or MacWeek) > said that there wasnt much in it, but they would choose the Ether+ over the >Nodem and the Nuvolink was the same animal as the Ether+ in a different box. .... >There is a problem with these SCSI ethernet devices and CE Software's Quickmail >at some point, if you use the SCSI ehternet box on the MailServer, both the >SCSI box and the QM Server try and grab the same interupt and the Mac hangs. >This explanation was offered by CE and they do not have a work around. There was a problem with the low level SCSI manager in early System 6.0.x versions of the OS. It's likely still there, though I understand it's to be fixed in 7.0. The problem: it's not re-entrant. And in certain, very very rare cases, with a heavily stressed AppleShare server multiple AFP requests simultaneously over a SCSI ethernet connection to/from a SCSI disk, the mac would hang; typically somewhere deep in HFS ROM code. It wouldn't surprise me if you are seeing this problem with Quickmail. A heavily used e-mail server, if it schedules it's multiple e-mail accesses in the wrong way, could hit this problem. For this reason Apple doesn't recommend using SCSI-Ethernet connections on AppleShare servers. Oh, as to what "very very rare" means: 5 other macs on ethernet doing continuous file & directory copies/creates/deletes simultaneously would usually trigger this problem after several days. Figuring 1 file/directory being created/deleted each second on each mac, that works out to it crashing after simultaneous stressing of 1,620,000 transactions. Pretty rare. It didn't help that the server was a Mac Plus (vs. an SE -- the Plus has the least impressive SCSI implementation...). Peter -- Moonlighting at Nuvotech when I'm not busy reading netnews... -- Peter "Arrgh" Korn korn@mica.Berkeley.EDU {decvax,hplabs,sdcsvax,ulysses,usenix}!ucbvax!mica!korn