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Newsgroups: comp.unix.bsd.freebsd.misc,comp.os.linux.development.system Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!newsroom.utas.edu.au!munnari.OZ.AU!spool.mu.edu!usenet.eel.ufl.edu!newsfeed.internetmci.com!howland.reston.ans.net!ix.netcom.com!netcom.com!jlemon From: jlemon@netcom.com (Jonathan Lemon) Subject: Re: The better (more suitable)Unix?? FreeBSD or Linux Message-ID: <jlemonDMtqK4.8H1@netcom.com> Organization: NETCOM On-line Communication Services (408 261-4700 guest) References: <4er9hp$5ng@orb.direct.ca> <4fg8fe$j9i@pell.pell.chi.il.us> <4fm2b1$ivs@park.uvsc.edu> <4fu70i$20q@pell.pell.chi.il.us> Date: Thu, 15 Feb 1996 15:48:04 GMT Lines: 47 Sender: jlemon@netcom22.netcom.com Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:13805 comp.os.linux.development.system:17359 In article <4fu70i$20q@pell.pell.chi.il.us>, Orc <orc@pell.chi.il.us> wrote: >In article <4fm2b1$ivs@park.uvsc.edu>, >Terry Lambert <terry@lambert.org> wrote: > >>The best paper I have seen on this so far is Gregory R. Ganger >>and Yale N. Pratt's paper "Metadata Update Performance in File >>Systems", where they propose a mechanism they term "soft updates". >> >>A related paper, Eric H. Herrin II and Raphael A. Finkel's "The >>Viva File System" goes into some detail on what constitutes an >>idempotent vs. a non-idempotent operation, and where you must >>guarantee order atomicity -- as does the UCB "SPRITE" paper. > > Where are these papers available? USENIX 1994 OPERATING SYSTEMS DESIGN AND IMPLEMENTATION PROCEEDINGS Gregory R. Ganger, Yale N. Patt Department of EECS, University of Michigan ganger@eecs.umich.edu Abstract Structural changes, such as file creation and block allocation, have consistently been identified as file system performance problems in many user environments. We compare several implementations that maintain metadata integrity in the event of a system failure but do not require changes to the on-disk structures. In one set of schemes, the file system uses asynchronous writes and passes ordering requirements to the disk scheduler. These scheduler-enforced ordering schemes outperform the conventional approach (synchronous writes) by more than 30 percent for metadata update intensive benchmarks, but are suboptimal mainly due to their inability to safely use delayed writes when ordering is required. We therefore introduce soft updates, an implementation that asymptotically approaches memory-based file system performance (within 5 percent) while providing stronger integrity and security guarantees than most UNIX file systems. For metadata update in- tensive benchmarks, this improves performance by more than a factor of two when compared to the conventional approach. The proceedings can be ordered from USENIX (http://www.usenix.org) or the paper may be on the umich server somewhere. I believe the VIVA paper was also presented at a USENIX conference, but I don't know which one. Disclaimer: I haven't read any of these papers.. :-( -- Jonathan