[Vdo-devel] Questions on write policy, discard and thin provisioning

[Miroslav Suchý]

Dne 1.3.2018 v 16:33 Gionatan Danti napsal(a):
> 3) when using VDO for virtual machine storage the recommended ratio is 10:1 - ie advertise a 10 TB device with a real 1
> TB disk. Great. But what happen if the compression/deduplication ratio is below expectation, maybe way below the 10:1
> ratio? I expect the VDO to fill, with the upper layer filesystem ignoring the problem (ie: it see much "free space").
> With lvm thin provisining this is a serious problem which was thoroughly discussed in the mailing list. What about VDO?

The same as e.g. when you exhaust number of inodes. Despite the 'df' saying that you have free space, you will be unable
to write to disk and you will get IO error.

Miroslav