[linux-lvm] segfaults and "VGDATA .. inconsistent" beta7 tools

[Heinz J. Mauelshagen]

On Tue, May 15, 2001 at 09:04:54AM +0100, Paul Jakma wrote:
> I have the same problem with 2 machines.
> 
> They are both running 2.4.5-pre1 with LVM 0.9.1beta7 patch applied and
> the beta7 RPMs. On boot they run vgscan then vgchange -ay. (and
> i've tried running pvscan too)
> 
> problem is thus:
> 
> [root at ns /root]# vgdisplay
> vgdisplay
> --- Volume group ---
> VG Name               VG01
> VG Access             read/write
> VG Status             available/resizable
> VG #                  0
> MAX LV                256
> Cur LV                7
> Open LV               6
> MAX LV Size           1023.97 GB
> Max PV                256
> Cur PV                1
> Act PV                1
> VG Size               13.61 GB
> PE Size               16 MB
> Total PE              871
> Alloc PE / Size       297 / 4.64 GB
> Free  PE / Size       574 / 8.97 GB
> VG UUID               8HMZzp-xzeK-13Fu-D4vx-a3hM-GhED-gUsh1x
> 
> 
> [root at ns /root]# vgdisplay -v
> vgdisplay
> Segmentation fault (core dumped)
> 
> [root at ns /root]# pvdisplay /dev/ida/c0d0p6
> pvdisplay
> pvdisplay -- ERROR "pv_read(): pv_create_name_from_kdev_t" no VALID
> physical volume "/dev/ida/c0d0p6"

The lvm library sets up a device name/number cache in order to map
between those. If pv_create_name_from_kdev_t() returns (char*)NULL, an
entry for /dev/ida/c0d0p6 couldn't be found in the cache :-(
Even though /dev/ida/ is a supported namespace, the entry couldn't have made
it into the cache, because the stat() on the device returned an error.

In order to check this, you could for eg. add a "printf ("found %s\n", devpath)"
after the sprintf() in lvm_add_dir_cache() in lvm_dir_cache.c and
and a "printf ("ADDED %s\n", devpath)" after the cache_size++ in the
same function.

BTW: long time ago, we were faced with problems related to messy /dev/ entries.
     In case you don't run devfs you need to make sure that /dev/ entries are
     all right.

> 
> [root at ns /root]# vgextend VG01 /dev/ida/c0d0p6
> vgextend
> vgextend -- INFO: maximum logical volume size is 1023.97 Gigabyte
> vgextend -- ERROR "pv_read_all_pv(): lvm_dir_cache" can't extend;
> couldn't read physical volume data
> 
> [root at ns /root]# vgcfgbackup
> vgcfgbackup
> vgcfgbackup -- volume groups found: VG01
> vgcfgbackup -- ERROR -262 checking existence of colume group "VG01"
> vgcfgbackup -- ERROR "vg_cfgbackup(): vg_check_exist" backing up
> volume group VG01
> 
> so i do a vgscan:
> 
> [root at ns /root]# vgscan
> vgscan
> vgscan -- reading all physical volumes (this may take a while...)
> vgscan -- "/etc/lvmtab" and "/etc/lvmtab.d" successfully created
> vgscan -- WARNING: This program does not do a VGDA backup of your
> volume group
> 
> and from now on, no more segfaults instead:
> 
> [root at ns /root]# vgdisplay -v
> vgdisplay
> vgdisplay -- ERROR: VGDA in kernel and lvmtab are NOT consistent;
> please run vgscan
> 
> [root at ns /root]# vgextend VG01 /dev/ida/c0d0p6
> vgextend
> vgextend -- ERROR: VGDA in kernel and lvmtab are NOT consistent;
> please run vgscan
> 
> etc.. etc...
> 
> is this a known problem? And what other debug output would be helpful?

No.
See above.

> 
> thanks,
> 
> Paul Jakma
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm at sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm

-- 

Regards,
Heinz    -- The LVM Guy --

*** Software bugs are stupid.
    Nevertheless it needs not so stupid people to solve them ***

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Heinz Mauelshagen                                 Sistina Software Inc.
Senior Consultant/Developer                       Am Sonnenhang 11
                                                  56242 Marienrachdorf
                                                  Germany
Mauelshagen at Sistina.com                           +49 2626 141200
                                                       FAX 924446
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