Date: Thu, 25 Jul 2002 19:25:03 -0400 (EDT) From: Jerry McAllister <jerrymc@clunix.cl.msu.edu> To: paulbeard@mac.com (paul beard) Cc: jerrymc@clunix.cl.msu.edu (Jerry McAllister), freebsd-questions@freebsd.org Subject: Re: restoring disklabel from an active disk? Message-ID: <200207252325.g6PNP4b16158@clunix.cl.msu.edu> In-Reply-To: <3D408348.9000300@mac.com> from "paul beard" at Jul 25, 2002 04:01:28 PM
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> > yup, I got the part about the incore label but too late: I wish > there was some way to refresh it. It is "active" as far as df -k > or the mechanism in the kernel that tracks filesystems knows. Hmmm. I just thought of something. You say the disklabel starts at 0. Do you mean the offset? That is the normal place to start. That is 0 relative to the slice it is in, not the cylinder, track, sector. The only things you really need to pay much attention to in the part of the disklabel output regarding the "partitions" are the partition letter, the size, the offset and the fstype. (There are a couple of other things in the list before that that need to be correct, but they normally are figured out correctly by the system so just keep those values - you can add a label name if you like). So, if it is just the offset that starts at 0 you might still be in good shape. ////jerry > > Jerry McAllister wrote: > >>I seem not to have that anymore: the disklabel that I get back > >>starts at 0. I seem to have trashed that as well while I was > >>thrashing around with this. <grumble> > > > > > > Oh Oh, Sounds suspiciosly like it be gone then. Well, this is > > your opportunity to be creative... > > > > ////jerry > > > > > >>I take the point about writing the output of disklabel to a file > >>AND lpr much more seriously than I did this morning. > >> > >>Thanks. > >> > >>Jerry McAllister wrote: > >> > >>>>I somehow wiped out my disklabel and while I am backing up my home > >>>>directory in the event I need to start from scratch, I would like > >>>>know if I can somehow extract a valid disklabel from a running > >>>>system and re-apply it? > >>> > >>> > >>>If you can get disklabel to print out the incore version of the label > >>>and it looks correct, just pipe that output to a file and then use > >>>that file as input to write the label. It is pretty well spelled > >>>out in the man page for disklabel. If you use the file, you don't > >>>need much else, just tell it to write the on disk copy of the label > >>>and not just update the in core label. It's all there. > >>> > >>>In fact, it can be handy to keep a copy of your disklabels in > >>>files on some other easily accessible online storage for such occasions. > >>> > >>>////jerry > >>> > >>> > >>> > >>>>I have everything mounted. > >>>>Filesystem 1K-blocks Used Avail Capacity Mounted on > >>>>/dev/ad0s2a 128990 42770 75902 36% / > >>>>/dev/ad0s2f 257998 532 236828 0% /tmp > >>>>/dev/ad0s2g 7179502 5481904 1123238 83% /usr > >>>>/dev/ad0s2e 257998 225462 11898 95% /var > >>>>procfs 4 4 0 100% /proc > >>>> > >>>>and disklabel offers to apply this information to the disk, but > >>>>I'm not sure it's right: there was an NTFS partition covering the > >>>>first 4 Gb. So starting from 0 doesn't look right to me. But then > >>>>that is slice 2 . . . . > >>>> > >>>>8 partitions: > >>>># size offset fstype [fsize bsize bps/cpg] > >>>> a: 262144 0 4.2BSD 2048 16384 94 # (Cyl. > >>>> 0 - 17*) > >>>> b: 492720 262144 swap # (Cyl. > >>>> 17*- 49*) > >>>> c: 16390080 0 unused 0 0 # (Cyl. > >>>> 0 - 1083) > >>>> e: 524288 754864 4.2BSD 2048 16384 94 # (Cyl. > >>>> 49*- 84*) > >>>> f: 524288 1279152 4.2BSD 2048 16384 94 # (Cyl. > >>>> 84*- 119*) > >>>> g: 14586640 1803440 4.2BSD 2048 16384 89 # (Cyl. > >>>>119*- 1083*) > >>>> > >>>>I guess what I need is how to map the mounted filesystems to the > >>>>right disklabel values. > >>>> > >>>>I'm not on the list, so direct replies would be most helpful. > >>>> > >>>>Thanks. > >>>> > >>>>-- > >>>>Paul Beard / 8040 27th Ave NE / Seattle WA 98115 / > >>>>paulbeard [at] mac [ dot] com / 206 529 8400 > >>>> > >>>>http://paulbeard.no-ip.org/movabletype > >>>> > >>>>Any sufficiently advanced technology is indistinguishable from magic. > >>>> -- Arthur C. Clarke > >>>> > >>>> > >>>>To Unsubscribe: send mail to majordomo@FreeBSD.org > >>>>with "unsubscribe freebsd-questions" in the body of the message > >>>> > >>> > >>> > >> > >>-- > >>Paul Beard / 8040 27th Ave NE / Seattle WA 98115 / > >>paulbeard [at] mac [ dot] com / 206 529 8400 > >> > >>http://paulbeard.no-ip.org/movabletype > >> > >>To the best of my recollection, Senator, I can't recall. > >> > >> > > > > > > > -- > Paul Beard / 8040 27th Ave NE / Seattle WA 98115 / > paulbeard [at] mac [ dot] com / 206 529 8400 > > http://paulbeard.no-ip.org/movabletype > > Stop searching. Happiness is right next to you. Now, if they'd only > take a bath ... > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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