Volume group / volumes not activated at boot

Volume group / volumes not activated at boot

[David Rosenstrauch]

For several months now, my server has be been failing to activate all 
volume groups / volumes at boot.  My server has 3 PV's, 3 VG's, and 4 
LV's.  But for some reason only 3 of the 4 LV's are activated after boot.

I can subsequently activate the VG manually (vgchange -ay vg2) and then 
mount the LV.  But the fact that the LV never activates automatically at 
boot time means that I can't add it in the fstab to so that it mounts at 
boot.

The start of the problem seems to coincide with when my distro (Arch 
Linux) moved to using lvmetad for device discovery.  But the distro's 
LVM package maintainer has reviewed my logs and can't see any reason why 
the volume group is not getting activated.

I've posted a verbose LVM debug log that I obtained while booting my 
device into single user mode.  (See http://www.darose.net/lvm2.log) 
You'll notice a few odd things in the log:  e.g., vg2 and vg2/lvshare 
never get activated, /etc/lvm/backup/vg2 never gets read or written, etc.

Details of my environment are as follows:
OS:	Arch Linux
Kernel:	3.11.6
Architecture:	x86_64
device-mapper version:	2.02.103
LVM version:	2.02.103

Any help greatly appreciated!

Best,

DR

Re: Volume group / volumes not activated at boot

[Zdenek Kabelac]

Dne 23.10.2013 17:05, David Rosenstrauch napsal(a):
> For several months now, my server has be been failing to activate all volume
> groups / volumes at boot.  My server has 3 PV's, 3 VG's, and 4 LV's.  But for
> some reason only 3 of the 4 LV's are activated after boot.
>
> I can subsequently activate the VG manually (vgchange -ay vg2) and then mount
> the LV.  But the fact that the LV never activates automatically at boot time
> means that I can't add it in the fstab to so that it mounts at boot.
>
> The start of the problem seems to coincide with when my distro (Arch Linux)
> moved to using lvmetad for device discovery.  But the distro's LVM package
> maintainer has reviewed my logs and can't see any reason why the volume group
> is not getting activated.

IMHO in normal case distro should ensure that only devices needed for the
system are activated on the boot.

So if you need all your volumes from a VG active - just add somewhere in your
boot sequence    'vgchange -ay' if you need all LVs active.

There is also recently a support for 'autoactivated' LVs - but this needs 
lvmetad daemon running in your system.

Zdenek

Re: Volume group / volumes not activated at boot

[David Rosenstrauch]

On 10/24/2013 05:32 AM, Zdenek Kabelac wrote:
> IMHO in normal case distro should ensure that only devices needed for the
> system are activated on the boot.
>
> So if you need all your volumes from a VG active - just add somewhere in
> your
> boot sequence    'vgchange -ay' if you need all LVs active.
>
> There is also recently a support for 'autoactivated' LVs - but this
> needs lvmetad daemon running in your system.
>
> Zdenek

Thanks for the response.

Actually after some additional research last night, I was able to figure 
out what the problem is:

The single PV in vg2 is a full disk device (/dev/sdc), not a partition. 
However, when I first was initializing the drive to add in to LVM, I 
accidentally partitioned the drive first.  Realizing the mistake, I then 
deleted the partitions.  However the result was a drive with an empty 
partition table, instead of a drive with no partition table. So what 
must be happening is that when LVM scans the drive, it sees that it's 
partitioned, but sees no partitions, and then moves on, leaving the VG 
inactive.  When I later manually tell LVM to activate the group 
explicitly it works; it just can't do it automatically.

Wiping out the partition table (i.e., MBR) on the drive seems to fix the 
issue, and LVM can now see the VG at boot.

Thanks,

DR