Hi all, I want to use bcache(ssd as cache and sas/sata as backend disk) to improve performance in ceph v12.2.x, and bluestore uses lvm as the default. When the bcache backend disk breakdown, I want to remove bcache device, so I remove the lvm on it firstly, but the OS is panic during removing. my questions are: 1. I want to know if it is necessary to use lvm? I got some considerations from http://lists.ceph.com/pipermail/ceph-users-ceph.com/2018-February/024388.html, but are there more? 2. If I do not use lvm, what harms are there in the future? for example the upgrade of ceph.
