Re: [linux-lvm] metadata problems while testing lvm2 git with dm_thin_pool

[Sebastian Riemer <sebastian.riemer@profitbricks.com>]

Hi Stefan,

I had a similar issue some time ago.

Which vgcreate commands did you use?

The last device in the list is used for the meta data. If you don't give
it a further device for the metadata then LVM puts the metadata onto the
same device like the data resulting in your issue.

Do it like this:

vgcreate thinvg /dev/sda /dev/sdb
lvcreate -L 10G -T thinvg/pool1
lvcreate -V 100G -T thinvg/pool1 -n disk1

The data is put on /dev/sda and the metadata is put on /dev/sdb. You can
only use the size of /dev/sda for the data. /dev/sdb shouldn't be bigger
than 16 GiB or your wasting disk space. You can also use a regular 16
GiB LV as PV and put it as metadata device into the VG.

Looks like this:
pvcreate /dev/sdb
vgcreate meta /dev/sdb
lvcreate -L 16G meta -n meta1
vgcreate thinvg /dev/sda /dev/mapper/meta-meta1
lvcreate -L 10G -T thinvg/pool1
lvcreate -V 100G -T thinvg/pool1 -n disk1

Cheers,
Sebastian


On 27.07.2012 14:29, Stefan Priebe - Profihost AG wrote:
> Hello list,
>
> i'm testing dm_thin_pool with lvm2 right now. And i'm always running
> into the situation that the metadata get's full.
>
> Kernel: 3.5-rc7
> lvm/dmeventd: up2date git version 186a2772
>
> I created my thin disk like this:
> lvcreate -L 10G -T thinvol/pool1 -V 100G --name disk1
>
> After some autoresizing lvs looks like this:
> # lvs
>   LV    VG      Attr     LSize   Pool  Origin Data%  Move Log Copy%
> Convert
>   disk1 thinvol Vwi-a-tz 100,00g pool1         22,95
>   pool1 thinvol twi-a-tz  33,77g               67,97
>
> # dmsetup table
> thinvol-pool1: 0 70811648 linear 253:4 0
> thinvol-disk1: 0 209715200 thin 253:4 1
> thinvol-pool1-tpool: 0 70811648 thin-pool 253:2 253:3 128 0 0
> thinvol-pool1_tdata: 0 20971520 linear 8:17 2048
> thinvol-pool1_tdata: 20971520 49840128 linear 8:17 20998144
> MYVOL-thin_pool2_tdata: 0 20971520 linear 8:129 2048
> MYVOL-thin_pool2_tdata: 20971520 31227904 linear 8:129 20998144
> thinvol-pool1_tmeta: 0 24576 linear 8:17 20973568
> MYVOL-thin_pool2_tmeta: 0 24576 linear 8:129 20973568
>
> Last log messages:
> lvm[2786]: Monitoring thin thinvol-pool1-tpool.
> lvm[2786]: Logical volume pool1 successfully resized
> lvm[2786]: Thin thinvol-pool1-tpool is now 100% full.
> lvm[2786]: Extending logical volume pool1 to 33,77 GiB
> lvm[2786]: Monitoring thin thinvol-pool1-tpool.
> lvm[2786]: Logical volume pool1 successfully resized
> lvm[2786]: Thin thinvol-pool1-tpool is now 84% full.
> lvm[2786]: dm_task_run failed, errno = 22, Invalid argument
> lvm[2786]: No longer monitoring thin thinvol-pool1-tpool.
> lvm[2786]: No longer monitoring thin thinvol-pool1-tpool.
> lvm[2786]: Thin metadata thinvol-pool1-tpool is now 99% full.
> lvm[2786]: Resize for thinvol/pool1 is not yet supported.
>
> Greets
> Stefan
>
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