[linux-lvm] Newbie: Yet another "Incorrect metadata area header checksum"

[linux-lvm] Newbie: Yet another "Incorrect metadata area header checksum"

[Simon Waters]

Installed Debian Lenny using NetInst CD 5.0.3 i386 dated  20090906-12:06 onto 
a DELL SC1425 with two SATA disks.

The system had previously had Centos 5.4 installed with LVM. The Debian 
installer was fighting back a little (because of this?), but eventually I 
picked "Guided Install with LVM" and it behaved in a plausible fashion 
(/dev/sda1 for /boot, /dev/sda2 for LVM, lots of partitions because I asked 
for them).

All seemed to go fine. The system installed, and booted, I shrunk /home file 
system and then logical volume, then expanded /home to fit the new lv size. I 
add /dev/sdb1 to the only volume group, add a logical volume. Basically 
convinced myself LVM was working and that I could administer it.

The I turned my attention to the error message that some of the commands 
produced: "Incorrect metadata area header checksum", since it looked 
annoying.

I've tried a lot of things rather blindly. The first occurance is in the 
installer log after the message "Queuing package e2fsprogs for later 
installation" from "Main-Menu" so presumably in response to me using the 
Debian installer menu's to set up LVM. This suggests it all went pear shaped 
before I had the opportunity to mistype stuff at the command line.

One suggestion was to install "dmraid" and look for metadata using this.
It produces:
 /dev/sdb: ddf1. ".ddf1_disks", GROUP, ok, 155989151 sectors, data@ 0
 /dev/sda: ddf1. ".ddf1_disks", GROUP, ok, 155989151 sectors, data@ 0

Attempts to erase this with "dmraid -rE" as suggested in one post fail with a 
three lines of:

ERROR: seeking device "/dev/sdb" to 40959999737856
ERROR: writing metadata to /dev/sdb, offset 79999999488 sectors, size 0 bytes 
returned 0
ERROR: erasing ondisk metadata on /dev/sdb
(and same for /dev/sda).

Other suggestion was make sure Debian Lenny packages were upto date. They are. 
The netinst CD just does that now - I'm sure it didn't always do that but I 
double checked and no updates are available.

This is my first (Linux) LVM install - be gentle.

Did I fail in preparing my disks in some way?

Re: [linux-lvm] Newbie: Yet another "Incorrect metadata area header checksum"

[Luca Berra]

On Mon, Feb 01, 2010 at 06:28:29PM +0000, Simon Waters wrote:
>Installed Debian Lenny using NetInst CD 5.0.3 i386 dated  20090906-12:06 onto 
>a DELL SC1425 with two SATA disks.
>
....
>One suggestion was to install "dmraid" and look for metadata using this.
>It produces:
> /dev/sdb: ddf1. ".ddf1_disks", GROUP, ok, 155989151 sectors, data@ 0
> /dev/sda: ddf1. ".ddf1_disks", GROUP, ok, 155989151 sectors, data@ 0
>
i believe your dell machine configured the two disks in a fakeraid,
yet Lenny does not know (you did not tell it or you forced it to ignore
the fakeraid) and tries to use the two disks independently.
This will lead to problems since at every boot the fakeraid bios will
touch the two disks.

back up your data
decide wether you want to use the fakeraid or not
configure your bios accordingly
reinstall your OS accordingly

L.

-- 
Luca Berra -- bluca@comedia.it
         Communication Media & Services S.r.l.
  /"\
  \ /     ASCII RIBBON CAMPAIGN
   X        AGAINST HTML MAIL
  / \

Re: [linux-lvm] Newbie: Yet another "Incorrect metadata area header checksum"

[Simon Waters]

On Tuesday 02 February 2010 06:55:48 Luca Berra wrote:
>
> >One suggestion was to install "dmraid" and look for metadata using this.
> >It produces:
> > /dev/sdb: ddf1. ".ddf1_disks", GROUP, ok, 155989151 sectors, data@ 0
> > /dev/sda: ddf1. ".ddf1_disks", GROUP, ok, 155989151 sectors, data@ 0

> back up your data

I haven't restored it to this machine yet - so that bit was easy.

> decide wether you want to use the fakeraid or not
> configure your bios accordingly

I'd decided not already after appalling experiences of fakeraid from DELL 
before.

The BIOS has the embedded SATA controller set to "ATA Mode" not RAID, and this 
was the same throughout the installation.

Setting the BIOS to RAID revealed one RAID-1 array, which one can then delete, 
and then converting the system back to ATAMODE, and everything on disk is 
well and truely hosed (hence the backup suggestion no doubt, and several dire 
warnings from the BIOS). I looked to see if I could recover anything from 
this, as I thought it might be useful exercise in recovering systems but it 
didn't look hopeful.

Perils of state buried in an inherited machine. I note that the RAID BIOS 
reports that the state of the RAID-1 array was fine, I think I'm remembering 
why I've come to hate the fakeraid stuff. I'm also not sure about the wisdom 
of confirming pressing the "Y" key by asking the user to press the "Y" key 
again.

Anyway I've now reinstalled after the above, and "dmraid -r" now reports "No 
RAID disks".

However in the installer log I still have the same error about incorrect 
metadata area header checksum.

The is first reported looking for the old Volume Group (so the installer found 
my old LVM information, even if I couldn't with the installer in rescue 
mode). But when partman-lvm in the Debian installer starts it reports.

Volume group "h78" successfully created

/dev/cdrom: open failed: Read-only file system

Incorrect metadata area header checksum

Only thing I did outside Debian Lenny Guided install with LVM was to 
recreate "root" bigger and "home" smaller.

Excluding the /dev/cdrom device in /etc/lvm/lvm.conf doesn't help.

Is this due to old metadata on the disk, or is there something going wrong in 
the installation process.

Since /dev/sda2 contains the root volume (amongst others) I assume any attempt 
to reset this data will require me to boot from a rescue CD?

 Simon

Re: [linux-lvm] Newbie: Yet another "Incorrect metadata area header checksum"

[Simon Waters]

On Tuesday 02 February 2010 10:21:30 Simon Waters wrote:
> Is this due to old metadata on the disk, or is there something going wrong
> in the installation process.

dd if=/dev/zero of=/dev/sda
dd if=/dev/zero of=/dev/sdb

From the Debian install CD, and then a reboot (otherwise the Debian installer 
remembers the old LVM information it read from disk when it booted, and 
complains things aren't like the use to be.

Re: [linux-lvm] Newbie: Yet another "Incorrect metadata area header checksum"

[Stuart D. Gathman]

On Tue, 2 Feb 2010, Simon Waters wrote:

> On Tuesday 02 February 2010 10:21:30 Simon Waters wrote:
> > Is this due to old metadata on the disk, or is there something going wrong
> > in the installation process.
> 
> dd if=/dev/zero of=/dev/sda
> dd if=/dev/zero of=/dev/sdb
> 
> >From the Debian install CD, and then a reboot (otherwise the Debian installer 
> remembers the old LVM information it read from disk when it booted, and 
> complains things aren't like the use to be.

Above wipes entire disk - which is good for a fresh install.  But
just making sure.  Not so good if you wanted to keep some partitions...

A faster way to wipe the entire disk is to use the security erase
feature of SMART disks available via /sbin/hdparm.

-- 
	      Stuart D. Gathman <stuart@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.