On 12/12/19 11:08 PM, Naohiro Aota wrote:
Supporting the RAID5/6 profile in HMZONED mode is not trivial. For example, non-full stripe writes will cause overwriting parity blocks. When we do a non-full stripe write, it writes to the parity block with the data at that moment. Then, another write to the stripes will try to overwrite the parity block with new parity value. However, sequential zones do not allow such parity overwriting. Furthermore, using RAID5/6 on SMR drives, which usually have a huge capacity, incur large overhead of rebuild. Such overhead can lead to higher to higher volume failure rate (e.g. additional drive failure during rebuild) because of the increased rebuild time. Thus, let's disable RAID5/6 profile in HMZONED mode for now. Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx> Signed-off-by: Naohiro Aota <naohiro.aota@xxxxxxx>
Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx> Thanks, Josef
