Messages in this thread | | | Date | Mon, 14 Jan 2002 14:16:30 +0300 | From | Hans Reiser <> | Subject | Re: [reiserfs-list] Boot failure: msdos pushes in front of reiserfs |
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Oleg Drokin wrote:
>Hello! > >On Sun, Jan 13, 2002 at 11:38:03PM +0100, Matthias Andree wrote: > >>3. I presume that msdos is linked into the kernel, and is thus tried >> first as root file system, the kernel then panicks as it cannot find >> /sbin/init (of course, it's in ReiserFS format, not msdos). >> >It is tried _and_ somewhat succesfuly, because there is still MSDOS "superblock". > > >>4. I asked Ewald to boot with rootfstype=reiserfs, but he reported that >> this did not help, news:<a1sb7b$t2d2e$1@ID-47183.news.dfncis.de> >> (German-language). >> >Hm, probably because reiserfs is not in kernel, but is an external module. > >>5. It seems as though some traces of FAT16 shining through reiserfs >> still make msdos think it can actually mount the file system. >> >Exactly. > >>I see various points where this can be attacked: >>1. SuSE and other distributors' installation tools, when formatting a >> partition with mkfs, should zero out the first couple of MBytes with >> dd if=/dev/zero of=/dev/hda13 bs=4096 count=1024 or something. I'm >> not exactly sure how much is needed to get rid of the msdos traces. >> >Erasing first 512 bytes block is enough to get rid fo msdos superblock, I think. > >>2. mkreiserfs could also zero out so much of old data on the FS so that >> the kernel reliably recognizes the FS as reiserfs and fails to mount >> that stuff as msdos >> >External tools (lilo and stuff) can live there, this will destroy them. > >Correct solution, if you create filesystem with mkreiserfs, and you >have no reliable way to pass fstype to kernel, when this partition is mounted >should be to destroy all occurences of other fs's superblocks by yourself, obviously. > >>3. Distributors, when making their initrd stuff, should make sure that >> all Linux-native file systems are tried first. >> >FS tryout order is hard-wired into the kernel (and depends on linking order, AFAIK). > >>Ewald has only recently migrated from Windows to Linux and direly wants >>his installation to boot. For now, I asked him to recompile his kernel >>to let msdos, umsdos and vfat be only modules rather than linked into >>the kernel, rebuild his initrd with SuSE's mk_initrd and rerun lilo, >>that should work around his problem, but it's certainly not good and may >>turn away people from Linux who are less enduring and patient than >>Ewald. >> >why have not you asked him to do 'dd if=/dev/zero of=/dev/his_partition bs=512 count=1'? >(and this won't destroy existing reiserfs filesystem). > >Bye, > Oleg >- >To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html >Please read the FAQ at http://www.tux.org/lkml/ > > So what solution should we use, zeroing or fixing msdos to not try something reiserfs can find, or both or what?
I want the solution to also fixes the error messages from msdos that it issues when it sees reiserfs that are confusing for users.
Hans
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