Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!ogicse!cs.uoregon.edu!ns.uoregon.edu!duff.uoregon.edu!jqj From: jqj@duff.uoregon.edu (JQ Johnson) Newsgroups: comp.mail.mh Subject: Re: FAQ Message-ID: <1991Apr5.235625.3788@ns.uoregon.edu> Date: 5 Apr 91 23:56:25 GMT References: <27913.670882599@castor> Sender: news@ns.uoregon.edu Reply-To: jqj@duff.uoregon.edu (JQ Johnson) Organization: University of Oregon Network Services Lines: 35 In the recently posted FAQ appears the advice that people should use the (otherwise undocumented?) LOCKF option when building mh 6.7. After I read the FAQ, I looked at the code, found that the option did in fact exist (basically, it means that Unix-style locking uses mandatory lockf() instead of flock()), and rebuilt my mh 6.7.1 distribution for my set of SPARCstations running SunOS 4.1.1. We run with an NFS-shared /var/spool/mail, so lockf() semantics (being global to the NFS system) are in principal better than flock. First thing I noticed was that zotnet/mts/lock.c didn't compile. In SunOS 4.1.1 you need to include to get the symbol F_ULOCK. OK, easy to add... Almost immediately after rebuilding I started seeing problems; whenever a workstation crashed it would result in a hung lock, forcing me to kill and restart rpc.lockd and rpc.statd on the server for /var/spool/mail. Worse, I presume that /bin/mail (which sendmail calls to do delivery) uses *.lock style locking, so the major potential contention problem on one's maildrop is not addressed with LOCKF-style locking. I've rolled back. Have other people using Suns been using the LOCKF option? With what success? I note that the option uses *mandatory* locks, a feature that Sun strongly deprecates. Bottom line is that I believe that the FAQ is wrong, and that at least on SunOS one should *not* define LOCKF and should use LOK_BELL instead. So, I recommend in mtstailor: lockstyle: 1 -- JQ Johnson Director of Network Services Internet: jqj@oregon.uoregon.edu University of Oregon voice: (503) 346-1746 250E Computing Center BITNET: jqj@oregon Eugene, OR 97403-1212 fax: (503) 346-4397