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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!bunyip.cc.uq.oz.au!munnari.OZ.AU!news.ecn.uoknor.edu!paladin.american.edu!gatech!news.mathworks.com!zombie.ncsc.mil!nntp.coast.net!howland.reston.ans.net!surfnet.nl!sun4nl!rnzll3!sys3.pe1chl!rob From: rob@pe1chl.ampr.org (Rob Janssen) Subject: Re: The better (more suitable)Unix?? FreeBSD or Linux X-Newsreader: NN version 6.5.0 (NOV) Reply-To: pe1chl@wab-tis.rabobank.nl Organization: PE1CHL Message-ID: <Dnw3qn.G29@pe1chl.ampr.org> References: <DnoqB4.2sy@pe1chl.ampr.org> <4hirl9$nr7@gizmo.nas.nasa.gov> <Dnu8FD.CK2@pe1chl.ampr.org> <4hl00v$7it@coyote.Artisoft.COM> Date: Thu, 7 Mar 1996 09:01:35 GMT Lines: 37 Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:14923 comp.os.linux.development.system:18722 In <4hl00v$7it@coyote.Artisoft.COM> mday@elbereth.org (Matt Day) writes: >In article <Dnu8FD.CK2@pe1chl.ampr.org> pe1chl@wab-tis.rabobank.nl writes: >>In <4hirl9$nr7@gizmo.nas.nasa.gov> truesdel@gizmo.nas.nasa.gov (Dave Truesdell) writes: >> >>>The point you seem to want to ignore is, while data integrity is not >>>guaranteed, it only affects those files being written at the time of a >>>crash. If you don't guarantee metadata integrity, you could loose *every* >>>file on an active filesystem. >> >>Please show us how that can happen, and how sync metadata is going to >>avoid it. I think you are only spreading FUD. >>(or is there some inherent fragility in FFS that is not in the classic >>UNIX filesystems and ext2fs?) >There appears to be some confusion about exactly why sequenced metadata >updates are necessary. I have previously recommended that everybody >read the fine technical reports (RTFTR?) on the subject, but that >didn't seem to end the confusion. So, I will summarize the facts from >the technical reports, and perhaps that will end the confusion. [summary deleted] The examples in your summary only show the well-known cases of files or blocks being lost when the system crashes. The problem can only occur with files that were being modified at the time of the crash. As we know by now, the content of such files is not reliably known anyway (because of delayed data writes). None of your examples shows how "you could loose *every* file on an active filesystem", and I still think this is FUD. Rob -- +------------------------------------+--------------------------------------+ | Rob Janssen rob@knoware.nl | BBS: +31-302870036 (2300-0730 local) | | AMPRnet: rob@pe1chl.ampr.org | AX.25 BBS: PE1CHL@PI8WNO.#UTR.NLD.EU | +------------------------------------+--------------------------------------+