On 2018/10/14 下午7:08, waxhead wrote:
> In case BTRFS fails to WRITE to a disk. What happens?

Normally it should return error when we flush disk.
And in that case, error will leads to transaction abort and the fs goes
RO to prevent further corruption.

> Does the bad area get mapped out somehow?

No.

> Does it try again until it
> succeed or until it "times out" or reach a threshold counter?

Unless it's done by block layer, btrfs doesn't try that.

> Does it eventually try to write to a different disk (in case of using
> the raid1/10 profile?)

No. That's not what RAID is designed to do.

It's only allowed to have any flush error if using "degraded" mount
option and the error is under tolerance.

Thanks,
Qu