Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!think.com!mintaka!bloom-beacon!eru!hagbard!sunic!mcsun!ukc!stl!cel!ir From: ir@cel.co.uk (ian reid) Newsgroups: comp.unix.sysv386 Subject: SV1K reliability (summary) Keywords: SV1K reliability Message-ID: <7454@suns302.cel.co.uk> Date: 6 Dec 90 14:31:24 GMT Organization: Crosfield Ltd., Hemel Hempstead, United Kingdom. Lines: 49 A long time ago I posted a question on the reliability of the SV1K file system to the net, and promised a summary. Unfortunately the response was underwhelming. Which is why this summary is so late. The thread lasted five or six messages before going off at a noisy tangent discussing what was and what wasn't a UPS. In brief the question was why did my system lose files when a power loss occurred. I can accept I would lose files which were being modified at the time, but I was losing (or having corrupted) some indeterminate files which made my system unbootable. My configuration was running 386/ix 2.0.1, with a 40Mb disk attatched to a ST506 controller, inside an Intel301Z box with 9126K extended memory. I received a reply from Ed Hall saying :- I've run ISC's 2.0.1 for over a year, now, with assorted power failures and crashes (I have a WD-1006SRV controller which locks up every few weeks or so--a known problem between that model and several UNIX's). I've never lost a file except for files which were being updated during the crash--and even that occurance has been quite rare. I received a reply from "LCDR Michael E. Dobson" saying:- My system, an AT&T 3B2/600G running AT&T Sys V R 3.2.2 supposedly has a hardened file system, however, I have had to restore from a boot floppy and tape on occaision after a power failure. Because of this, in addition to an UPS, I have installed a powerfailure monitor which automaticly begins the shutdown sequence when it senses a powerfailure from the primary power source. The UPS provides sufficient time for users to log off and for the sutdown sequnce to complete. For a cost of ~$250 for the transducer/software, it's a very good investment. E-mail if you want details on the product. That was about it. However around that time my newsfeed went down and I missed some messages which were quoted as references in Michael's article. These apparently according to Michael merely stated why the problem couldn't happen. They may also have included an explanation of file system hardening which would still be useful. Apologies for the (very) late summary. -- Ian Reid #include UUCP: ir@cel.uucp or ir@cel.co.uk or ...!{ukc,mcsun,uunet}!cel!ir "Computers..proof positive that no-one yet understands how to describe any real world situation in 0's and 1's."