[linux-lvm] Re: After power outtage my vg is gone

[linux-lvm] Re: After power outtage my vg is gone

[Klaus Pedersen]

Hi again,
I really need help on this - sorry to send another request for help.
Does anybody have a clue ? anything that can help me remount my vg without
dataloss if possible ?
Can anybody point me to documentation in saving a vg ? or a newsgroup on
usenet I can try ?

To say it another way - _any_ help would be appreciated !

Thanks in advance

/Klaus Pedersen

----- Original Message -----
From: "Klaus Pedersen" <ultra@mailme.dk>
To: <linux-lvm@sistina.com>
Sent: Sunday, October 28, 2001 7:09 PM
Subject: After power outtage my vg is gone


> I'm using Debian Linux on 2.4.6 (and whatever version of LVM that comes
with
> it).
> After accidentaly pushing the power switch on my Linux server and starting
> it up again, I have problems mounting my vg again.
>
> This is what happens :
>
> Vault:/home/ultra# mount /glftpd/site
> mount: /dev/site_vg/lvol1 is not a valid block device
> Vault:/home/ultra# vgscan
> vgscan -- reading all physical volumes (this may take a while...)
> vgscan -- found inactive volume group "site_vg"
> vgscan -- ERROR "vg_read_with_pv_and_lv(): allocated LE of LV" can't get
> data of volume group "site_vg" from physical volume(s)
> vgscan -- ERROR "vg_read_with_pv_and_lv(): allocated LE of LV" creating
> "/etc/lvmtab" and "/etc/lvmtab.d"
>
> Vault:/home/ultra#
>
>
> I read through the archive of the list because I am absolutely sure I am
not
> the first who had this problem. I read some stuff about using the
uuid_fixer
> tool, bit as far as I was able to read, the problem that fixes only shows
up
> after extending the VG (Which I did a week or so, ago), and only for
kernels
> up to 2.4.5.
> Is this true ?
>
> Vault:~/uuid_fixer# ./uuid_fixer /dev/hda8 /dev/hdb1
>
> UUIDs discovered:
> W9tkR7eq026WBMCBrUCdebI32vRyFuLn
> u5vBzCHwu5mjAt5yN0lS4Ecrto1jI9NZ
>
> I tried running it anyway, and after that I ran vgscan - and the same
> problems showed up.
>
> What do I do to recoved my data ?
>
>
> Any help is greatly appreciated
>
> /Klaus
>

Re: [linux-lvm] Re: After power outtage my vg is gone

[Andreas Dilger]

On Oct 31, 2001  07:37 +0100, Klaus Pedersen wrote:
> I really need help on this - sorry to send another request for help.
> Does anybody have a clue ? anything that can help me remount my vg without
> dataloss if possible ?
> Can anybody point me to documentation in saving a vg ? or a newsgroup on
> usenet I can try ?

Try "vgcfgrestore".

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/

Re: [linux-lvm] Re: After power outtage my vg is gone

[Klaus Pedersen]

I think that gave a little breakthrough :-)
First of all - as murphys law suggests, I don't have a backup to use with
vgcfgrestore - but with the tool I did manage to recreate both /etc/lvmtab
and /etc/lvmtab.d :

Vault:/home/ultra# vgcfgrestore -n site_vg /dev/hda8
vgcfgrestore -- VGDA for "site_vg" successfully restored to physical volume
"/dev/hda8"

Vault:/home/ultra# vgcfgrestore -n site_vg /dev/hdb1
vgcfgrestore -- VGDA for "site_vg" successfully restored to physical volume
"/dev/hdb1"

the only problem is that they are both really empty, so with vgscan I find
nothing :

Vault:/etc# vgscan
vgscan -- reading all physical volumes (this may take a while...)
vgscan -- no volume groups found

But to my big relief, the data is still present on the physical drives :

Vault:/etc# pvdisplay /dev/hda8
--- Physical volume ---
PV Name               /dev/hda8
VG Name               site_vg
PV Size               14.1 GB / NOT usable 1.21 MB [LVM: 135 KB]
PV#                   2
PV Status             available
Allocatable           yes
Cur LV                1
PE Size (KByte)       4096
Total PE              3610
Free PE               108
Allocated PE          3502
PV UUID               W9tkR7-eq02-6WBM-CBrU-Cdeb-I32v-RyFuLn


Vault:/etc# pvdisplay /dev/hdb1
--- Physical volume ---
PV Name               /dev/hdb1
VG Name               site_vg
PV Size               57.25 GB / NOT usable 3.96 MB [LVM: 178 KB]
PV#                   1
PV Status             NOT available
Allocatable           yes (but full)
Cur LV                1
PE Size (KByte)       4096
Total PE              14654
Free PE               0
Allocated PE          14654
PV UUID               u5vBzC-Hwu5-mjAt-5yN0-lS4E-crto-1jI9NZ


Thanks for the help so far Andreas, but where do I go from here ?

Thanks in advance

Klaus Pedersen

----- Original Message -----
From: "Andreas Dilger" <adilger@turbolabs.com>
To: <linux-lvm@sistina.com>
Sent: Wednesday, October 31, 2001 7:52 AM
Subject: Re: [linux-lvm] Re: After power outtage my vg is gone


> On Oct 31, 2001  07:37 +0100, Klaus Pedersen wrote:
> > I really need help on this - sorry to send another request for help.
> > Does anybody have a clue ? anything that can help me remount my vg
without
> > dataloss if possible ?
> > Can anybody point me to documentation in saving a vg ? or a newsgroup on
> > usenet I can try ?
>
> Try "vgcfgrestore".
>
> Cheers, Andreas
> --
> Andreas Dilger
> http://sourceforge.net/projects/ext2resize/
> http://www-mddsp.enel.ucalgary.ca/People/adilger/
>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html

Re: [linux-lvm] Re: After power outtage my vg is gone

[Klaus Pedersen]

Hi again

I finally got my problem solved, so I write this message to tell others how
I solved it, so it's in the mail archives - and also because I want to point
out that this should be in the HOW-TO, since my problem is probably not so
uncommonm and very easy to solve - IF you know how.

Basically my problem is that after a power outtage I was unable to mount my
vgs - I got this message :

Vault:/home/ultra# mount /glftpd/site
mount: /dev/site_vg/lvol1 is not a valid block device

I found out that the problem is that the file /etc/lvmtab and the directory
/etc/lvmtab.d is gone for some reason.

Basically I solved this with a big help from Andreas to dropped me a short
message to use vgcfgrestore, so I did.
In the how-to I find it very vagely documented exactly what this tool does,
and when it's being used.
Also, I was unable to read in the how-to that after this is the sequence of
commands that should be used :
vgcfgrestore -n site_vg /dev/hda8
vgcfgrestore -n site_vg /dev/hdb1
(my vg consists of those two partitions)

vgscan -a y (to activate the vg)

and then do the actual mounting :

mount /glftpd/site

Yes, I know that to some very experienced LVM developer and such, this is
VERY simple - but to a guy like me who really doesn't know much about LVM,
it was very advanced and hard to find out.

So please - put an advanced troubleshooting guide in the LVM how-to on
sistina.com - I find it very hard to believe that I am the only one who
could use it.

/Klaus


----- Original Message -----
From: "Klaus Pedersen" <ultra@mailme.dk>
To: <linux-lvm@sistina.com>
Sent: Wednesday, October 31, 2001 8:17 AM
Subject: Re: [linux-lvm] Re: After power outtage my vg is gone


> I think that gave a little breakthrough :-)
> First of all - as murphys law suggests, I don't have a backup to use with
> vgcfgrestore - but with the tool I did manage to recreate both /etc/lvmtab
> and /etc/lvmtab.d :
>
> Vault:/home/ultra# vgcfgrestore -n site_vg /dev/hda8
> vgcfgrestore -- VGDA for "site_vg" successfully restored to physical
volume
> "/dev/hda8"
>
> Vault:/home/ultra# vgcfgrestore -n site_vg /dev/hdb1
> vgcfgrestore -- VGDA for "site_vg" successfully restored to physical
volume
> "/dev/hdb1"
>
> the only problem is that they are both really empty, so with vgscan I find
> nothing :
>
> Vault:/etc# vgscan
> vgscan -- reading all physical volumes (this may take a while...)
> vgscan -- no volume groups found
>
> But to my big relief, the data is still present on the physical drives :
>
> Vault:/etc# pvdisplay /dev/hda8
> --- Physical volume ---
> PV Name               /dev/hda8
> VG Name               site_vg
> PV Size               14.1 GB / NOT usable 1.21 MB [LVM: 135 KB]
> PV#                   2
> PV Status             available
> Allocatable           yes
> Cur LV                1
> PE Size (KByte)       4096
> Total PE              3610
> Free PE               108
> Allocated PE          3502
> PV UUID               W9tkR7-eq02-6WBM-CBrU-Cdeb-I32v-RyFuLn
>
>
> Vault:/etc# pvdisplay /dev/hdb1
> --- Physical volume ---
> PV Name               /dev/hdb1
> VG Name               site_vg
> PV Size               57.25 GB / NOT usable 3.96 MB [LVM: 178 KB]
> PV#                   1
> PV Status             NOT available
> Allocatable           yes (but full)
> Cur LV                1
> PE Size (KByte)       4096
> Total PE              14654
> Free PE               0
> Allocated PE          14654
> PV UUID               u5vBzC-Hwu5-mjAt-5yN0-lS4E-crto-1jI9NZ
>
>
> Thanks for the help so far Andreas, but where do I go from here ?
>
> Thanks in advance
>
> Klaus Pedersen
>

Re: [linux-lvm] Re: After power outtage my vg is gone

[Andreas Dilger]

On Nov 01, 2001  19:54 +0100, Magosányi Árpád wrote:
> Another item which needs inclusion is the bit about restoring the
> uuid. I think of that little perverse 'dd' commands which should
> be done with pw_uuidlist_on_disk.base.

This is now handled by the "uuid_fixer" commands, which are included
in the LVM CVS, I think (I don't know if it is installed).

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/

Re: [linux-lvm] Re: After power outtage my vg is gone

[Klaus Pedersen]

>
> vgscan -a y (to activate the vg)

Duh - this is an error (I know cause the same problems occured - again :P)
.. the command _should_ have said :

vgchange -a y

so the sequence of commands is :

vgcfgrestore -n site_vg /dev/hdb1
vgcfgrestore -n site_vg /dev/hda8
vgchange -a y
mount /glftpd/site

That's it - I hope others can benefit from this too.

/Klaus