> > I have about 100TB of mailboxes in Maildir format on NFS (NetApp FAS) > and works very well, for performance but also stability.
Hmmm, I would like to read something else. Eg that the design/elementary properties of distributed storage result into that all such systems are performing about the same. Maybe there should be more focus on ceph performance development instead of this cephadm? > The main problem of using Ceph or GlusterFS to store Maildir is the high > use of metadata that dovecot require for check new messages and others > activity. On my storage/NFS the main part of the traffic and I/O is > metadata traffic on small file (high file count workload). That is why I am using mdbox files of 4MB. I hope that should give me hardly any write amplification. I am also seperating between ssd and hdd pools by auto archiving email to the hdd pools > > And Ceph or GlusterFS are very inefficient with this kind of workload > (many metadata GETATTR/ACCESS/LOOKUP and high numer of small files). I am using rbd. After luminuous I had some issues with the cephfs and do not want to store operational stuff on it yet.
