root@nebulus.UUCP (Dennis S. Breckenridge) (06/23/89)
In article <2294@drilex.UUCP>, dricejb@drilex.UUCP (Craig Jackson drilex1) writes: > In article <12044@bloom-beacon.MIT.EDU> jfc@athena.mit.edu (John F Carr) writes: > >In article <14401@bfmny0.UUCP> tneff@bfmny0.UUCP (Tom Neff) writes: > Personally, I've always thought that update(8) was a hack, ever since I > first saw it in Version 7. To think that someone would write an operating > system that couldn't even keep its on-disk data structures consistent... > Going back to V7 days when a file system corrupted itself you had to spend many hours on the console. This is reduced with the development of several tools to allow you to repair a broken file system. With the release of file system hardening this was reduced even more. What is the problem with sync today and sync of V7 days. V7 sync forced a flush of the system pool to disk, SYSV sync tags dirty buffers for a next scheduled update. Consider for a moment several users updating the super-block and buffer pools asyncronously. The system would spend a great deal of time on disk and the user runtime would starve. By tagging buffers for update to happen at the next AUTOUP time relieves the kernel from actually forcing a disk write to complete before the call completes. This allows several buffers to get written to before the actual memory to disk write happens. My question really is how else would you do it effectively. I read many complaints about how Eh-TNT did this but what I do not read is a proactive solution to the problem. Buy the source and fix it, send the diffs to Eh-TNT and see if you can add your name the list of thousands that worked on it. I believe that a company the size of AT&T that releases its product in source format for a small sub-license fee is doing the right thing. Try that with the other vendors out there. Unix is portable, name some others with it's functionality and general availability. There is GNU... -- ============================================================================== "A mind is a terrible thing to MAIL: Dennis S. Breckenridge waste!" 206 Poyntz Ave North York, Ontario M2N1J6 (416) 733-1696 UUCP: uunet!attcan!nebulus!dennis ICBM: 79 28 05 W / 43 45 01 N 50 megatons should do! ==============================================================================