[linux-lvm] ReCreating the 1st 512 bytes of PV

lvm-list.mail at nex-consult.com lvm-list.mail at nex-consult.com
Thu Feb 26 13:12:04 UTC 2004 

Hi All:

While freeing my System from Windows (parallel installation)
the Win. - HardDisk-Managagement tool informed me that something has
been "corrected" on a disk partition. (My Linux LVM - device!)

/dev/hda5 contains one Volume Group "vg00" and the Logical Volumes
"lvol01", "lvol02" and "lvol03"

It seems to be a Windows boot sector or something like this, because of
"55aa" ??

In the following the 1st 512 bytes of my /dev/hda5 
****************
0000000: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000010: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000020: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000030: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000040: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000050: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000060: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000070: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000080: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000090: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000100: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000110: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000120: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000130: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000140: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000150: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000160: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000170: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000180: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000190: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00001a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00001b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00001c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00001d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00001e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00001f0: 0000 0000 0000 0000 0000 0000 0000 55aa  ..............U.
****************

I've tryed to fix it manually by comparing the bytes with another
system.
Now, the modified version:

****************
0000000: 484d 0100 0000 0000 0004 0000 0010 0000  HM..............
0000010: 0010 0000 0020 0000 8080 0000 00b0 0000  ..... ..........
0000020: 4849 0100 0000 0200 0000 4100 3030 3030  HI........A.0000
0000030: 3131 3131 3232 3232 3333 3333 3434 3434  1111222233334444
0000040: 3535 3535 3636 3636 3737 3737 0000 0000  555566667777....
0000050: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000060: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000070: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000080: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000090: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000a0: 0000 0000 0000 0000 0000 0000 7667 3030  ............vg00
00000b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000100: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000110: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000120: 0000 0000 0000 0000 0000 0000 7468 6567  ............theg
0000130: 6174 6531 3037 3735 3535 3239 3000 0000  ate1077555290...
0000140: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000150: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000160: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000170: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000180: 0000 0000 0000 0000 0000 0000 0000 0000  ................
0000190: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00001a0: 0000 0000 0000 0000 0000 0000 0300 0000  ................
00001b0: 0100 0000 0100 0000 0200 0000 0bb6 fd00  ................
00001c0: 0100 0000 0020 0000 ee07 0000 ee07 0000  ..... ..........
00001d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00001e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00001f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................

****************

--> now I can see more, but it doesn´t work.


root at 0[hda7]# pvdisplay  /dev/hda5
--- Physical volume ---
PV Name               /dev/hda5
VG Name               vg00
PV Size               7.93 GB [16627211 secs] / NOT usable 4.19 MB [LVM:
135 KB]
PV#                   1
PV Status             available
Allocatable           yes (but full)
Cur LV                1
PE Size (KByte)       4096
Total PE              2030
Free PE               0
Allocated PE          2030
PV UUID               000011-1122-2233-3344-4455-5566-667777


****************

root at 0[hda7]# vgscan
vgscan -- reading all physical volumes (this may take a while...)
vgscan -- ERROR "pv_read_all_pv_of_vg(): no PV" can't get data of volume
group "vg00" from physical volume(s)
vgscan -- "/etc/lvmtab" and "/etc/lvmtab.d" successfully created
vgscan -- WARNING: This program does not do a VGDA backup of your volume
group


****************
root at 0[hda7]# lvmdiskscan
lvmdiskscan -- reading all disks / partitions (this may take a while...)
lvmdiskscan -- /dev/hda1  [       4.88 GB] Primary   [0x07]
lvmdiskscan -- /dev/hda2  [      32.37 GB] Primary   [0x0F]
lvmdiskscan -- /dev/hda5  [       7.93 GB] Extended LVM partition [0x8E]
lvmdiskscan -- /dev/hda6  [      31.38 MB] Extended LINUX native
partition [0x83]
lvmdiskscan -- /dev/hda7  [      24.41 GB] Extended LINUX native
partition [0x83]
lvmdiskscan -- 1 disk
lvmdiskscan -- 0 whole disks
lvmdiskscan -- 0 loop devices
lvmdiskscan -- 0 multiple devices
lvmdiskscan -- 0 network block devices
lvmdiskscan -- 5 partitions
lvmdiskscan -- 1 LVM physical volume partition
****************

I´ve found "/etc/lvmtab.d/vg00", "/etc/lvmconf/vg00.conf" and
"/etc/lvmtab" on a backup 
(which doesn´t contain my real important data)

But: 

root at 0[hda7]# vgcfgrestore -n vg00 /dev/hda5
vgcfgrestore -- INFO: using backup file "/etc/lvmconf/vg00.conf"
vgcfgrestore -- ERROR: different structure size stored in
"/etc/lvmconf/vg00.conf" than expected in file vg_cfgrestore.c [line
120]
vgcfgrestore -- ERROR "vg_cfgrestore(): read" restoring volume group
"vg00"
****************

.. to locate the file-systems directly on /dev/hda5/, "dd" them into a
file and mount it as loop-back-device works 
slightly, but contains only a few usable data (after fsck.reiserfs
--rebuilt-tree), mostly only files with crap content.


****************

Could someone help me please ???!!!??????


Thanks & Regards
Tobias Katzer

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