Jun Zeng

> This are the changes for feature of using QLC NVMe SSD to store bulk data. It mainly includes 3 points: 1. support configuring QLC NVMe tier with newly added...

> Please don't rebase and force-push once your work has begun to be reviewed, or if you really need to (such as for changing base branch), please don't fixup or...

Have add commits to support exist pool created from old software version which not support the QLC NVMe, and to be compatible with client rpc interface compiled from old software...

> > I think both pmem or md-on-ssd mode should be able to support QLC capacity tier. > > @NiuYawei please reconsider whether it is a valuable investment right now....