Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site utah-gr.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!think!harvard!seismo!utah-cs!utah-gr!thomas From: thomas@utah-gr.UUCP (Spencer W. Thomas) Newsgroups: net.unix-wizards Subject: Re: Vax Unix tape problem Message-ID: <1612@utah-gr.UUCP> Date: Sat, 26-Oct-85 19:02:05 EST Article-I.D.: utah-gr.1612 Posted: Sat Oct 26 19:02:05 1985 Date-Received: Tue, 29-Oct-85 00:36:12 EST References: <117@gsg.UUCP> Reply-To: thomas@utah-gr.UUCP (Spencer W. Thomas) Organization: Univ of Utah CS Dept Lines: 29 In article <117@gsg.UUCP> kathy@gsg.UUCP (Kathryn Smith) writes: > The first problem is that both the nightly and the level 0 dumps seem >unable to cope with writing a full tape of information. Dump aborts on a >tape write error consistently somewhere in the last 400 feet of a 2400 foot >mag tape. This is apparently a software error, since no hardware diagnostics >are showing up on the console. > > I tried instumenting a copy of dump to find out what is going on, and >found that the error is coming from the unix write primitive. The error code >returned is 'I/O error' (enlightening). Right now we are functioning by >running dump with the size option specifying a tape size of 2000 feet, but >don't want to keep doing this for obvious reasons. Ah yes... Good old dump and it's "tape estimating" feature. Dump thinks it knows how many blocks will fill a 2400 foot tape, but depending on your tape drive, it can be pretty far off. Looks like your drive writes larger inter-record gaps than dump thinks it "should". So, only "2000 feet" of data will fit on your tape. The "I/O error" means that the drive has seen the end-of-tape marker, and is not really an error at all, except that dump can't handle it intelligently. You will have to keep on using a "tape size" of 2000 feet, because you're really using the whole tape. Watch it sometime, and see. -- =Spencer ({ihnp4,decvax}!utah-cs!thomas, thomas@utah-cs.ARPA) "When wrath runs rampage in your heart you must hold still that rambunctions tongue!" - Sappho