[linux-lvm] Questions

[Stuart D. Gathman]

On Mon, 5 Mar 2007, Heinz Mauelshagen wrote:

> On Sat, Mar 03, 2007 at 08:59:38PM -0500, Stuart D. Gathman wrote:
> > Which display commands display on-disk metadata, which display 
> > lvmtab/lvmtab.d, and which display kernel data structures?  I'd like to 
> > know if the metadata is trashed on my original two PVs, or just on
> > the new one I tried to add.
> 
> Because you're refering to LVM1, you see kernel metadata unless you
> provide the -D option to the *display commands.

Why did vgdisplay refuse to display anything until I restored
/etc/lvmtab.d/rootvg from the backup (prior to the attempted vgextend)?

What is the relationship between /etc/lvmconf backups and /etc/lvmtab.d?
Are they the same or different format?  I notice that the size is identical,
but there where byte differences when I compared them on the backup of the
working system.

What does this mean?

[root at cmslax root]# vgdisplay -D
vgdisplay -- ERROR: not all physical volumes of volume group "rootvg" online

And sure enough, 
[root at cmslax root]# pvdisplay /dev/md3
--- Physical volume ---
PV Name               /dev/md3
VG Name               rootvg
PV Size               16.87 GB [35374848 secs] / NOT usable 32.19 MB [LVM: 130 KB]
PV#                   3
PV Status             NOT available
Allocatable           yes
Cur LV                1
PE Size (KByte)       32768
Total PE              538
Free PE               481
Allocated PE          57
PV UUID               YfvIpi-x3Cg-xKrR-j1T2-Gutz-u1tp-sl8t01

/dev/md3 is most assuredly available and readable/writable.

> Make sure that your /etc/lvmconf backup is alright for your case
> by running "vgcfgrestore -ll -f ...".
> If so, vgcfgrestore it after initializing the PVs with pvcreate -f.

Why is the pvcreate necessary?  The PVs all have metadata displayable
with pvdisplay.  Pvdisplay has no -D option, so I assume it displays
on disk metadata.

-- 
	      Stuart D. Gathman <stuart at bmsi.com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.