[Gluster-users] Reconstructing files from shards

[Gandalf Corvotempesta]

2018-04-23 9:34 GMT+02:00 Alessandro Briosi <ab1 at metalit.com>:
> Is it that really so?

yes, i've opened a bug asking developers to block removal of sharding
when volume has data on it or to write a huge warning message
saying that data loss will happen

> I thought that sharding was a extended attribute on the files created when
> sharding is enabled.
>
> Turning off sharding on the volume would not turn off sharding on the files,
> but on newly created files ...

No, because sharded file are reconstructed on-the-fly based on the
volume's sharding property.
If you disable sharding, gluster knows nothing about the previous
shard configuration, thus won't be able to read
all shards for each file. It will only returns the first shard,
resulting in data-loss or corruption.