Hallo,
here we go again. As a matter of interest, what version of nilfs and what
distribution are you running? And what processor?
your endiannes confused me at first.
glad you fixed your hexedit
I have looked at some numbers in the superblock and they look ok. I do
wonder if you have the garbage collector running.
now for the second superblock. Please pay attention to the exact place of
it. Because it is of vital
importance if it in in partition 1 or in the root of the disk.
the first superblock sits as you observed in the root. The flags say amongst
others that it was unmounted cleanly but errors were detected.
see nilfs2_fs.h - NILFS2 on-disk structures and common declarations. in the
distribution.
/**
* struct nilfs_super_block - structure of super block on disk
*/
struct nilfs_super_block {
....
translates bit for bit to what you see written in the super block on disk.
Here is an example from a partition of mine on how to discover the
superblock copy
it should read the same as the 1st but in your case it might not.
It is a leftshift - subtract 1 - right shift algorithm.
go in hexedit to the last data with ">" (shift .)
note the address of the last byte (the size of the partion)
in mine:
6566B3F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
................
or the status line might give it
the address of the copy is now at 6566A000
i.e. 6566B has 1 subtracted from it and the 3 least significant digits have
been zeroed.
so please dump yours, see if the algorithm works on the 1st part or on the
root or both,
so we know where it is.
And check if it is exactly the same as the first one you send me
"0000400 0002 0000 0000 3434 0100 0000 b209 5b31"
etc.
the next thing to discover is where the start of (nilfs)segment 0 is.
I am not quite sure what is written in it, but the signature is quite
distinct.
This is what it looks on my machine:
00000FC0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
................
00000FD0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
................
00000FE0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
................
00000FF0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
................
00001000 C4 1B 47 5B 51 62 19 13 11 FA AF 1E 38 00 10 00
..G[Qb......8...
00001010 FB CE 01 00 00 00 00 00 EE BD F1 4A 00 00 00 00
...........J....
00001020 00 08 00 00 00 00 00 00 FF 07 00 00 32 00 00 00
............2...
00001030 A0 83 00 00 00 00 00 00 EE 0D 00 00 00 00 00 00
................
00001040 07 00 00 00 00 00 00 00 7B 00 00 00 7B 00 00 00
........{...{...
00001050 EA 9E 07 00 00 00 00 00 F8 01 00 00 00 00 00 00
................
00001060 EB 9E 07 00 00 00 00 00 F9 01 00 00 00 00 00 00
................
00001070 EC 9E 07 00 00 00 00 00 FA 01 00 00 00 00 00 00
................
00001080 ED 9E 07 00 00 00 00 00 FB 01 00 00 00 00 00 00
................
00001090 EE 9E 07 00 00 00 00 00 FC 01 00 00 00 00 00 00
................
000010A0 EF 9E 07 00 00 00 00 00 FD 01 00 00 00 00 00 00
................
000010B0 F0 9E 07 00 00 00 00 00 FE 01 00 00 00 00 00 00
................
000010C0 F2 9E 07 00 00 00 00 00 FF 01 00 00 00 00 00 00
................
000010D0 F3 9E 07 00 00 00 00 00 00 02 00 00 00 00 00 00
................
000010E0 F4 9E 07 00 00 00 00 00 01 02 00 00 00 00 00 00
................
000010F0 F5 9E 07 00 00 00 00 00 02 02 00 00 00 00 00 00
................
00001100 F6 9E 07 00 00 00 00 00 03 02 00 00 00 00 00 00
................
00001110 F7 9E 07 00 00 00 00 00 04 02 00 00 00 00 00 00
................
00001120 F8 9E 07 00 00 00 00 00 05 02 00 00 00 00 00 00
................
00001130 F9 9E 07 00 00 00 00 00 06 02 00 00 00 00 00 00
................
00001140 FA 9E 07 00 00 00 00 00 07 02 00 00 00 00 00 00
................
00001150 FB 9E 07 00 00 00 00 00 08 02 00 00 00 00 00 00
................
00001160 FC 9E 07 00 00 00 00 00 09 02 00 00 00 00 00 00
................
00001170 FD 9E 07 00 00 00 00 00 0A 02 00 00 00 00 00 00
................
00001180 FE 9E 07 00 00 00 00 00 0B 02 00 00 00 00 00 00
................
00001190 FF 9E 07 00 00 00 00 00 0C 02 00 00 00 00 00 00
................
000011A0 00 9F 07 00 00 00 00 00 0D 02 00 00 00 00 00 00
................
000011B0 01 9F 07 00 00 00 00 00 0E 02 00 00 00 00 00 00
................
000011C0 02 9F 07 00 00 00 00 00 0F 02 00 00 00 00 00 00
................
000011D0 03 9F 07 00 00 00 00 00 10 02 00 00 00 00 00 00
................
000011E0 04 9F 07 00 00 00 00 00 11 02 00 00 00 00 00 00
................
Segment 0 starts at hex 1000 of a nilfs partition as you can see above and
carries on for quite a while like this.
so have a look on your disk if it sits at 1000 of the root partition or at
1000 of partition 1.
Once we have these things sorted I would say that we are ready to plant the
_right_ superblock of the 2
in the right place and see if the partition is recoqnized by nilfs.
Off course we will save the place where we are going to plant that block
first.
And now back to the birthday party . . . .
Cheers,
Jan
On Wed, Nov 4, 2009 at 4:23 AM, Paul L <[email protected]> wrote:
> On 11/3/09, Jan de Kruyf <[email protected]> wrote:
> > 26 august 98: hexedit 0.9.5 release
> > september 2005:
> > - version 1.2.12 this is the one I am running.
>
> Ah, I must be using the wrong hexedit.. now I've installed the same one you
> use.
>
> > did I hear that you have always had /dev/mmcblk0p1 in fstab??
>
> Yes. What I put there is:
>
> /dev/mmcblk0p1 /home nilfs2 defaults 1 1
>
> > hd -n1536 /dev/mmcblk0 >part.start
> > hd -s8191 -n1536 /dev/mmcblk0 >part1.start
> > an to verify the last line:
> > hd -n1536 /dev/mmcblk0p1 >part1a.start
>
> Here is the output (I use hexdump instead of hd, hopefully they are the
> same)
>
> bash-3.1# cat part.start
> 0000000 0000 0000 0000 0000 0000 0000 0000 0000
> *
> 00001b0 0000 0000 0000 0000 0696 6c22 0000 0100
> 00001c0 0001 0383 ffd0 0010 0000 dff0 01eb 0000
> 00001d0 0000 0000 0000 0000 0000 0000 0000 0000
> *
> 00001f0 0000 0000 0000 0000 0000 0000 0000 aa55
> 0000200 0000 0000 0000 0000 0000 0000 0000 0000
> *
> 0000400 0002 0000 0000 3434 0100 0000 b209 5b31
> 0000410 1183 794c 0002 0000 07af 0000 0000 0000
> 0000420 0000 d780 0003 0000 0001 0000 0000 0000
> 0000430 0800 0000 0005 0000 090b 000e 0000 0000
> 0000440 0710 0035 0000 0000 8502 0008 0000 0000
> 0000450 8800 000b 0000 0000 93c1 493c 0000 0000
> 0000460 013f 4ae2 0000 0000 2a8f 4aef 0000 0000
> 0000470 00a2 0032 0003 0001 93c1 493c 0000 0000
> 0000480 4e00 00ed 0000 0000 0000 0000 000b 0000
> 0000490 0080 0020 00c0 0010 ed2b 04f5 41cb ae48
> 00004a0 7f8a 4849 71ec e7f5 0000 0000 0000 0000
> 00004b0 0000 0000 0000 0000 0000 0000 0000 0000
> *
> 0000600
> bash-3.1# cat part1.start
> 0001fff 0000 0000 0000 0000 0000 0000 0000 0000
> *
> 00025ff
> bash-3.1# cat part1a.start
> 0000000 0000 0000 0000 0000 0000 0000 0000 0000
> *
> 0000600
>
> Regards,
> Paul Liu
>
> > On Tue, Nov 3, 2009 at 9:48 PM, Paul L <[email protected]> wrote:
> >
> >> Thanks a lot for the instructions! I'm attaching the mbr and partition
> >> table with this email.
> >>
> >> I'm pretty sure I had 1 partition on the card, since my /etc/fstab
> >> mounts mmcblk0p1.
> >>
> >> I think something corrupted my disk first, and then what I've done to
> >> the disk after noticing the corruption:
> >>
> >> 1. fdisk, it says use "w" will correct the error, so I did. But then
> >> the one parition is gone.
> >> 2. fdisk again, create a single partition, then "w"
> >>
> >> My mistake was that I didn't create a backup copy of the MBR. A hard
> >> lesson learned :(
> >>
> >> Also, why is that my hexedit doesn't take the "-s" option? It's
> >> version 0.9.7, and can't edit bigger than 4.2GB.
> >>
> >> My SD card is A-DATA brand, class 6, and 16GB.
> >>
> >> I'm using Linux, and fdisk version (util-linux-ng 2.14.1)
> >>
> >> Regards,
> >> Paul Liu
> >>
> >> On 11/3/09, Jan de Kruyf <[email protected]> wrote:
> >> > hallo,
> >> > Almost sounds like you had only the root master-boot-record
> /dev/mmcblk0
> >> > before and now you have added 1 main partition /dev/mmcblk0p1.
> >> >
> >> > If (and only if) that is the case we have to undo the the 1st
> partition
> >> > +
> >> > check that no nilfs is overwritten.
> >> > and I would have to urgently study fdisk to see exactly what it writes
> >> when
> >> > and where.
> >> > The last time I did tricks like these is quit a few years ago.
> >> >
> >> > It is the Linux version of fdisk is it??
> >> >
> >> > So here is the plan of action:
> >> > hexdump the master boot record to file.
> >> > like this:
> >> >
> >> > dd if=/dev/mmcblk0 of=backup-mmcblk0.mbr count=1 bs=512
> >> >
> >> > then dump any partitions of the device in a format useful as input to
> >> > sfdisk. For example,
> >> > % sfdisk -d /dev/mmcblk0 > mmcblk0 .out
> >> > sfdisk is a tool provided with the util-linux
> >> > package<http://www.kernel.org/pub/linux/utils/util-linux/>.
> >> >
> >> >
> >> > or you could use hexdump to get machine readable or man readable
> images.
> >> > Here is the man readable version:
> >> > hd -n512 /dev/mmcblk0 > backup-mmcblk0.mbr
> >> > hd -n512 /dev/mmcblk0p1 >backup-mmcblk0p1.mbr
> >> > etc.
> >> >
> >> > By the way boor records always end with '55 AA'.
> >> >
> >> > Keep your files in a safe place in case we mess something we can at
> >> > least
> >> go
> >> > back to the present situation.
> >> > If you could dd the whole drive to a file, now that would be magic
> >> indeed!
> >> > but you must have the space on a harddrive.
> >> > count=... is the number of sectors in the above line (dd ...) that you
> >> dump
> >> > to file.
> >> > Hexedit will tell you the number of sectors is you start it with -s
> >> option
> >> > and then go to the last sector.
> >> > DONT stop hexedit with control-x use cntl-c.
> >> > DONT use high level or even midlevel tools on a stuffed disk, it
> >> > normally
> >> > messes more than it solves.
> >> > unless of course you really,really know what you are doing.
> >> > Fiddling the bytes is in general safe and gives results, if a man
> keeps
> >> > a
> >> > cool head.
> >> >
> >> > Please send me the fdisk version, the size of the card, and the mbr
> dump
> >> to
> >> > feast my eyes on.
> >> >
> >> > cheers,
> >> >
> >> > Jan de kruyf.
> >> >
> >> >
> >> >
> >> > On Tue, Nov 3, 2009 at 1:27 AM, Paul L <[email protected]> wrote:
> >> >
> >> >> just want to add that I've always been using 1 partition on this
> >> >> device, it's actually /dev/mmcblk0p1. But hexedit /dev/mmcblk0p1
> >> >> doesn't show that 34 34 at line begining with 0x400, only hexedit
> >> >> /dev/mmcblk0 shows it. Not sure if this is a problem.
> >> >>
> >> >> Any help is greatly appreciated!
> >> >>
> >> >>
> >> >> On 11/2/09, Paul L <[email protected]> wrote:
> >> >> > Thanks for the tips. When I first used the SD card, I used fdisk to
> >> >> > create the partition.
> >> >> >
> >> >> > The device is /dev/mmcblk0, and hexedit -d -s /dev/mmcblk0 shows
> that
> >> >> > at the line 0x0400, it is indeed 34 34. What should I do then?
> >> >> >
> >> >> > I tried gparted, but apparently it has no support for nilfs2.
> >> >> >
> >> >> > Regards,
> >> >> > Paul Liu
> >> >> >
> >> >> > On 11/2/09, Jan de Kruyf <[email protected]> wrote:
> >> >> >> Did you first format this card with fdisk?
> >> >> >> did you give it the exact same info this time around?
> >> >> >>
> >> >> >> Can you read /dev/'sdcard' ? (sdcard being the device in the dev
> >> >> >> directory
> >> >> >> where the card lives)
> >> >> >>
> >> >> >> If yes can you run hexedit -s /dev/sdcard1 in a terminal as root?
> >> >> >> and go to address 0400 - 04B0 to see if nilfs still exists?
> >> >> >>
> >> >> >> be very careful no to save any data in hexedit, it will definitely
> >> and
> >> >> >> finally
> >> >> >> destoy your data.
> >> >> >>
> >> >> >> 0400 looks vagely like this:
> >> >> >> 00000400 02 00 00 00 00 00 34 34 00 01 00 00 D3 56 F0 B9
> >> >> >> ......44.....V..
> >> >> >> 00000410 39 BF D9 73 02 00 00 00 CA 02 00 00 00 00 00 00
> >> >> >> 9..s............
> >> >> >> 00000420 00 B4 66 65 01 00 00 00 01 00 00 00 00 00 00 00
> >> >> >> ..fe............
> >> >> >> 00000430 00 08 00 00 05 00 00 00 01 00 00 00 00 00 00 00
> >> >> >> ................
> >> >> >> 00000440 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >> >> >> ................
> >> >> >> 00000450 00 48 16 00 00 00 00 00 73 95 DC 4A 00 00 00 00
> >> >> >> .H......s..J....
> >> >> >> 00000460 00 00 00 00 00 00 00 00 73 95 DC 4A 00 00 00 00
> >> >> >> ........s..J....
> >> >> >> 00000470 00 00 32 00 01 00 01 00 73 95 DC 4A 00 00 00 00
> >> >> >> ..2.....s..J....
> >> >> >> 00000480 00 4E ED 00 00 00 00 00 00 00 00 00 0B 00 00 00
> >> >> >> .N..............
> >> >> >> 00000490 80 00 20 00 C0 00 10 00 4C 73 DD 3D 01 EC 45 85 ..
> >> >> >> .....Ls.=..E.
> >> >> >> 000004A0 94 28 44 42 3D F6 EF EC 56 61 72 36 34 00 00 00
> >> >> >> .(DB=...Var64...
> >> >> >> 000004B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >> >> >> ................
> >> >> >> 000004C0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >> >> >> ................
> >> >> >>
> >> >> >> the 34 34 in the top line say this is nilfs.
> >> >> >>
> >> >> >>
> >> >> >> cheers
> >> >> >>
> >> >> >> jan de kruyf
> >> >> >>
> >> >> >>
> >> >> >>
> >> >> >>
> >> >> >> On Mon, Nov 2, 2009 at 9:06 PM, Paul L <[email protected]> wrote:
> >> >> >>
> >> >> >>> Due to some careless handling of my laptop, the SD card popped
> out
> >> >> >>> when the machine is still running. When I put it back in and
> reboot
> >> >> >>> the machine, it says "partition table error". I then ran fdisk
> and
> >> >> >>> recreated the single partition. Then I can no longer mount the
> >> nilfs2
> >> >> >>> partition that was on the SD card!
> >> >> >>>
> >> >> >>> Can any one help to me recover the file system? I believe all
> data
> >> are
> >> >> >>> still there, but just some bits and pieces are missing for the
> >> >> >>> mount
> >> >> >>> to work. Any help is greatly appreciated!
> >> >> >>>
> >> >> >>> PS: I've a deadline to meet in 4 hours, not sure if I can get my
> >> stuff
> >> >> >>> back in time... so help please!
> >> >> >>>
> >> >> >>> --
> >> >> >>> Regards,
> >> >> >>> Paul Liu
> >> >> >>>
> >> >> >>> Yale Haskell Group
> >> >> >>> http://www.haskell.org/yale
> >> >> >>> _______________________________________________
> >> >> >>> users mailing list
> >> >> >>> [email protected]
> >> >> >>> https://www.nilfs.org/mailman/listinfo/users
> >> >> >>>
> >> >> >>
> >> >> >
> >> >> >
> >> >> > --
> >> >> > Regards,
> >> >> > Paul Liu
> >> >> >
> >> >> > Yale Haskell Group
> >> >> > http://www.haskell.org/yale
> >> >> >
> >> >>
> >> >>
> >> >> --
> >> >> Regards,
> >> >> Paul Liu
> >> >>
> >> >> Yale Haskell Group
> >> >> http://www.haskell.org/yale
> >> >> _______________________________________________
> >> >> users mailing list
> >> >> [email protected]
> >> >> https://www.nilfs.org/mailman/listinfo/users
> >> >>
> >> >
> >>
> >>
> >> --
> >> Regards,
> >> Paul Liu
> >>
> >> Yale Haskell Group
> >> http://www.haskell.org/yale
> >>
> >> _______________________________________________
> >> users mailing list
> >> [email protected]
> >> https://www.nilfs.org/mailman/listinfo/users
> >>
> >>
> >
>
>
> --
> Regards,
> Paul Liu
>
> Yale Haskell Group
> http://www.haskell.org/yale
> _______________________________________________
> users mailing list
> [email protected]
> https://www.nilfs.org/mailman/listinfo/users
>
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