thin lvm and zeroing/chunk size


New Member
Jul 23, 2019
i have proxmox 6. I have add some hard disks and i have try to create a new thin lvm.
However when i create the thin lvm i have this warnings:
  Thin pool volume with chunk size 512,00 KiB can address at most 126,50 TiB of data.
  WARNING: Pool zeroing and 512,00 KiB large chunk size slows down thin provisioning.
  WARNING: Consider disabling zeroing (-Zn) or using smaller chunk size (<512,00 KiB).
  WARNING: Converting pve2/data2 to thin pool's data volume with metadata wiping.

What is the best to do? To disable zeroing or to change chunk size? And how?

I have read here:
the type PoolSize/ChunkSize * 64b = MetadataPoolSize

but it is not clear to me what to do?
Can someone help in order to have very stable and fast storage?
Thank you
the proxmox installer by default create Chunk 256,00k in version 5.X, and 64,00k in version 6.X
Seems that the debian 10 by default create 512,00 KiB
It is not something very critical but you can change the Chunk size with the -c option.
for example:
lvconvert --type thin-pool -c 64K  pve/data
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