[ILUG] Re: Small LVM issue

[Conor Wynne]

Like our good friend David, I cannot believe there were no responses to
this.
Anyway, I had a wee think about it and I believe I can take one of the two
following routes to resolve it.

Option 1

1. restore the backup LVM config so that it still contains the missing VG.

2. vgreduce the two additional LVM groups /dev/sdd1 and /dev/sdd2

3. vgcfgbackup database ; vgcfgrestore database ;

4. vgscan and if no complaints about UUID's then

5. vgreduce /dev/sdd & lastly

6. pvremove /dev/sdd

Or should I do :

Again, restore the backup LVM config so that it still contains the missing
VG.

# vgreduce /dev/sdd1 /dev/sdd2

# pvremove /dev/sdd1 /dev/sdd2

# fdisk /dev/sdd (remove two partitions) ; partprobe /dev/sdd

# pvcreate /dev/sdd --uuid 'BZwaqZ-zKZM-rXNo-MVuk-JfTM-MUHj-4bkTuK'
(which should bring it back to square one)

Then
# vgreduce /dev/sdd ; pvremove /dev/sdd

Will I get an answer this time round :-)

On Tue, Nov 24, 2009 at 1:43 PM, Conor Wynne <mariconor at gmail.com> wrote:

> Hi all,
>
> I've an LVM missing UUID issue.
>
> Situation:
> Added a new LUN and pvcreate /dev/sdd on it. Then added it to a VG and
> extended an lv.
> Then realised I needed to use half for one volgroup and the other half
> for another, so did:
>
> lvreduce -l -254 vgname etc
> Which is fine as I had only added 254 extents to the VG in the first
> place, and had not extended the filesystem since reiserfs doesn't
> support it online.
>
> I then did a pvremove -ff /dev/sdd and went about adding /dev/sdd1 and
> /dev/sdd2 to the new lvm set.
>
> Now I have this :
> /proc/partitions :
>   8    49   97667136 sdd1
>   8    50   45062325 sdd2
>
>  /dev/sdd1  [       93.14 GB] LVM physical volume
>  /dev/sdd2  [       42.97 GB] LVM physical volume
> (which are just empty partitions from the newly created LUN, no data on
> them yet, so no worries)
>
>  /dev/sdb   [      136.12 GB] LVM physical volume
> sdb has the database, which we have not touched yet, but need to extend
> by 20GB, not an issue, but I need to fix the missing UUID first.
>
> server:/etc/lvm/backup # vgscan
>  Reading all physical volumes.  This may take a while...
>  Couldn't find device with uuid 'BZwaqZ-zKZM-rXNo-MVuk-JfTM-MUHj-4bkTuK'.
>
> This is normal as /dev/sdd is no longer part of any LVM group. As sdd1
> and sdd2 are.
>
>  Couldn't find all physical volumes for volume group database.
>  Couldn't find device with uuid 'BZwaqZ-zKZM-rXNo-MVuk-JfTM-MUHj-4bkTuK'.
>  Couldn't find all physical volumes for volume group database.
>  Volume group "database" not found
>  Found volume group "system" using metadata type lvm2
> server:/etc/lvm/backup #
> server:/etc/lvm/backup #
> server:/etc/lvm/backup #
> server:/etc/lvm/backup #
> server:/etc/lvm/backup #
> server:/etc/lvm/backup # pvscan
>  Couldn't find device with uuid 'BZwaqZ-zKZM-rXNo-MVuk-JfTM-MUHj-4bkTuK'.
>  Couldn't find device with uuid 'BZwaqZ-zKZM-rXNo-MVuk-JfTM-MUHj-4bkTuK'.
>  PV /dev/sdb         VG database   lvm2 [136.12 GB / 21.12 GB free]
>  PV unknown device   VG database   lvm2 [136.12 GB / 136.12 GB free]
>
> It says unknown device because I commented out the UUID for missing
> device from the lvm backup configs.
>
>  PV /dev/sda6        VG system     lvm2 [125.80 GB / 0    free]
>  PV /dev/sda2        VG system     lvm2 [8.00 GB / 4.80 GB free]
>  PV /dev/sdd1                      lvm2 [93.14 GB]
>  PV /dev/sdd2                      lvm2 [42.97 GB]
>  Total: 6 [542.15 GB] / in use: 4 [406.04 GB] / in no VG: 2 [136.12 GB]
> server:/etc/lvm/backup # lvscan
>
>  /dev/sdc: open failed: No medium found
> (I know, I need to black list this, but it's not an issue)
>
>  Couldn't find device with uuid 'BZwaqZ-zKZM-rXNo-MVuk-JfTM-MUHj-4bkTuK'.
>  Couldn't find all physical volumes for volume group database.
>  Couldn't find device with uuid 'BZwaqZ-zKZM-rXNo-MVuk-JfTM-MUHj-4bkTuK'.
>  Couldn't find all physical volumes for volume group database.
>  Volume group "database" not found
>
> Which is not actually true, it just says this because not all members
> are there.
> As you can see:
>
>  ACTIVE            '/dev/system/opt_lv' [3.00 GB] inherit
>  ACTIVE            '/dev/system/root_lv' [4.00 GB] inherit
>  ACTIVE            '/dev/system/srv_lv' [3.00 GB] inherit
>  ACTIVE            '/dev/system/tmp_lv' [3.00 GB] inherit
>  ACTIVE            '/dev/system/usr_lv' [7.00 GB] inherit
>  ACTIVE            '/dev/system/var_lv' [3.00 GB] inherit
>  ACTIVE            '/dev/system/home_lv' [8.00 GB] inherit
>  ACTIVE            '/dev/system/backup_lv' [80.00 GB] inherit
>  ACTIVE            '/dev/system/informix_lv' [4.00 GB] inherit
>  ACTIVE            '/dev/system/parteor_lv' [10.00 GB] inherit
>  ACTIVE            '/dev/system/public_lv' [4.00 GB] inherit
>
> So, how can I remove theis issue without harming the dataset?
> Its not that big an issue, but I'd need to be careful all the same.
>
> Regards
> Conor.
>
>