Path: utzoo!attcan!uunet!husc6!uwvax!rutgers!mailrus!cornell!uw-beaver!uw-june!geops!johnf From: johnf@geops.UUCP (John Firestone) Newsgroups: comp.sys.ibm.pc Subject: Re: Filesystem speed on PC's (was: Re: ISDN) Summary: RT-11 file system suits its purpose Message-ID: <428@geops.geops.UUCP> Date: 16 Aug 88 19:18:19 GMT References: <18.23040D6B@rubbs1.FIDONET.ORG> <6108@bigtex.uucp> <237@pigs.UUCP> <3658@bsu-cs.UUCP> Organization: Geophysics, U of W, Seattle Lines: 28 In article <3658@bsu-cs.UUCP>, dhesi@bsu-cs.UUCP (Rahul Dhesi) writes: > > Last I checked some years ago, the RT-11 file system had the following > deficiencies: (a) it was not hierarchical, i.e., no subdirectories; > (b) it forced files to be contiguous, so you easily ran out of space > for a file to grow even if there was plenty of free space on disk. > > It's easy to design a file system with such defects and make it fast. > But that has nothing to do with UNIX or MS-DOS. Well, you can have a hierarchical file system under RT-11 in the form of nested logical disks (files of disk images). While these are not as flexible as a file system with a true hierarchical structure, they are ridiculously fast, since RT-11 implements them using a memory-resident device handler. Alas, they still require that the files on them be contiguous and usually non-extensible; packing disks once in a while (this is fast and easy) usually keeps you from running out of space, but you still may have an occasional "make" session abort for lack of space. Sigh. Despite its age, I think the RT-11 file system is not defective considering RT-11's purpose: to be small, fast and easy to use. While most people are not stuck with machines having only 16 kbytes of memory and DECTAPE for mass storage, for many of us the big machine we would like is impractical or unaffordable. RT-11's "toy" [not Rhahul's wording, but from someone off the net] file system gives a small computer system the raw performance of a large one and is almost trivial to understand and use. Most days, it will even do what you need it do. Isn't that what most people want in a small, personal computer?