Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site umcp-cs.UUCP Path: utzoo!watmath!clyde!burl!ulysses!harpo!seismo!rlgvax!cvl!umcp-cs!zben From: zben@umcp-cs.UUCP Newsgroups: net.unix-wizards Subject: Re: IBM and Univac Unix Message-ID: <6868@umcp-cs.UUCP> Date: Wed, 2-May-84 23:25:59 EDT Article-I.D.: umcp-cs.6868 Posted: Wed May 2 23:25:59 1984 Date-Received: Fri, 4-May-84 04:35:31 EDT References: <162@sri-arpa.UUCP>, <651@u1100a.UUCP> Organization: Univ. of Maryland, Computer Science Dept. Lines: 48 [There is a large, oversized SHell between you and your Unix...] Credentials: Systems Programmer on Univac 1100s since 1972. Paper published in CACM June 1975. Implementor of Software Tools version for Univac 1100 currently distributed by software tools user's group. Scuttlebutt (private communication with Univac insider) claims Univac bought Unix back from Bell and is developing it internally. Article for which this is a followup claims Bell is developing it internally. All that follows is based upon the version we have (but do not run) here at UOM. Its pretty amazing folks. They actually do all of Unix, including raw IO to terminals (if you run a Unix CCR) and the stopping and single-stepping of processes. Sort of. Only one process on the whole machine seems to be able to do it, but this is more an indictment of the Univac interprocess communication mechanism (or lack of same) than anything else. Still, you're going to be able to run just about half as many users under Unix as you could under the bare operating system. This might not be that unreasonable. I have it on good authority (from performance analysis freaks) that on a 4341 you waste about half your cycles by using VM rather than one of the more efficient IBM operating systems, and (from another source) that you can run about double the number of users on your vaxen were you to run VMS rather than Unix. There are also enormous gaping security holes in Univac Unix. This might not bother you terribly much as Unix seems to be wide open anyway, but consider the fact that I can write a 3 line C program that destroys an entire filesystem and there is nothing the system can do to prevent it. (For those who would understand, try CSF$('@FREE,D .'). There are some things that could be done to improve both the performance and security of this product. Undoutably Bell is working on it. Again rumor is that 50 users totally saturate an 1100/84, while we were running 177 on our 1100/82 (half as many CPUs) yesterday afternoon. I'm sure Bell doesn't like this any more than I do. Perhaps more importantly, Univac seems to be "migrating" its operating system to be able to do the things that Unix needs to do to improve both its performance and security. About two or three years down the pike Unix might be a very respectable product. I guess you pays your money and takes your chances. You have a tradeoff between absolute number of users you can handle, and what those users can do once they get on. Security may or may not be important in your particular environment. Each site must make its own choice... -- Ben Cranston ...seismo!umcp-cs!zben zben@umd2.ARPA