[linux-lvm] metadata device too small
zkabelac at redhat.com
Mon Jan 13 14:49:27 UTC 2020
Dne 13. 01. 20 v 15:32 Gionatan Danti napsal(a):
> On 12/01/20 19:11, Zdenek Kabelac wrote:
>> With 16G there is 'problem' (not yet resolved known issue) with different
>> max size used by thin_repair (15.875G) & lvm2 (15.8125G) tools.
>> If you want to go with current max size supported by lvm2 - use the value
> Hi Zdenek,
> just for confirmation: so using a 16 GiB thin metadata volume *will* result in
> activation problems? For example, a
> lvcreate --thin system --name thinpool -L 100G --poolmetadatasize 16G
> will be affected by the problem you wrote above?
> Finally, does it means that lvmthin man page is wrong when stating that "Thin
> pool metadata LV sizes can be from 2MiB to 16GiB" (note the GiB suffix rather
> than GB)?
Well the size is 'almost' 16GiB - and when the size of thin-pools metadata is
always maintained by lvm2 - it's OK - the size is internally 'clamped'
correctly - the problem is when you use this size 'externally' - so you make
16GiB regular LV used for thin-repair - and then you swap-in such LV into
So to make it clear - when you 'lvcreate' thin-pool with 16GiB of metadata -
it will work - but then when you will try to fix such thin-pool - it will
fail. So it's always better to create thin-pool with -L15.812G then using 16G.
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