On Mon, 29 Jul 2019 16:33:59 -0300 "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxxxxx> wrote: > Currently md/raid0 is not provided with any mechanism to validate if > an array member got removed or failed. The driver keeps sending BIOs > regardless of the state of array members. This leads to the following > situation: if a raid0 array member is removed and the array is mounted, > some user writing to this array won't realize that errors are happening > unless they check kernel log or perform one fsync per written file. > > In other words, no -EIO is returned and writes (except direct ones) appear > normal. Meaning the user might think the wrote data is correctly stored in > the array, but instead garbage was written given that raid0 does stripping > (and so, it requires all its members to be working in order to not corrupt > data). If that's correct, then this seems to be a critical weak point in cases when we have a RAID0 as a member device in RAID1/5/6/10 arrays. -- With respect, Roman