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Newsgroups: comp.os.386bsd.questions Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!elroy.jpl.nasa.gov!sdd.hp.com!col.hp.com!csn!hellgate.utah.edu!fcom.cc.utah.edu!cs.weber.edu!terry From: terry@cs.weber.edu (A Wizard of Earth C) Subject: Re: fsck summary info bad after every shutdown Message-ID: <1993May28.201446.24163@fcom.cc.utah.edu> Sender: news@fcom.cc.utah.edu Organization: Weber State University (Ogden, UT) References: <davidb.738071772@otto> <1tlqt4INN7ni@fstgds01.tu-graz.ac.at> <vp.738563799@news.forth.gr> Date: Fri, 28 May 93 20:14:46 GMT Lines: 42 In article <vp.738563799@news.forth.gr> vp@nemesis.csi.forth.gr (Vassilis Prevelakis) writes: >chmr@edvz.tu-graz.ac.at (Christoph Robitschko) writes: > >>I've modified fsck to check the clean bit, and ufs_mount and ufs_unmount >>in the kernel to clear and set the clean bit, respectively. It works >>fine after I manually unmount a partition, but my problem is that the >>filesystems are not unmounted automatically on a shutdown. > >Why not use fasthalt(8) or fastboot(8), these create a file (/fastboot) >so that after the machine is rebooted /etc/rc doesn't run fsck at all. This still does not ensure superblock integrity; marking the buffers for write versus calling bwrite on them (ala umount) are two very different things. Halt, by definition, should do a forcible unmount of partitions (this *is* supported, at least in UFS). An unmount should, among other things, write the volume info, set the bit in the volume info for "clean", and then rewrite the volume info. I think the "fsck -p" warnings on a count of reboots is unnecessary, but if you want to implement this Utrix feature (as has been suggested), then you might as well. SVR4 likes you to be in / when you shut down to avoid invalidating the vnode for the current directory, and to make it easy to run uadmin (out of sbin) to actually shut the system down. A paramter to halt would do the same thing for us without the "shutdown from /" bogosity. Using fasthalt(8) or fastboot(8) avoids the fsck, but doesn't actually make it unnecessary. The key is telling if it necessary or not, and then skipping it. PS: The forcible unmount is the reason for the "log off now or risk your files being damaged" message, since all processes will have been killed by that time, and well behaved processes are at no risk (they'll have cause the SIGTERM/SIGHUP/SIGINT from init). Terry Lambert terry@icarus.weber.edu --- Any opinions in this posting are my own and not those of my present or previous employers.