Hi, According to [1] there are new parameters in place to have the MDS behave more stable. Quoting that blog post "One of the more recent issues weve discovered is that an MDS with a very large cache (64+GB) will hang during certain recovery events."
For all of us that are not (yet) running Nautilus I wonder what the best course of action is to prevent instable MDS during recovery situations. Artificially limit the "mds_cache_memory_limit" to say 32 GB? I wonder if the amount of clients is of influence in a MDS being overwhelmed by release messages. Of are a handfull of clients (with millions of CAPS) able to overload an MDS? Is there a way, other than unmounting cephfs on clients, to decrease the amount of CAPS the MDS has handed out, before an upgrade to a newer Ceph release is undertaken when running luminous / Mimic? I'm assuming you need to restart the MDS to make the "mds_cache_memory_limit" effective, is that correct? Gr. Stefan [1]: https://ceph.com/community/nautilus-cephfs/ -- | BIT BV https://www.bit.nl/ Kamer van Koophandel 09090351 | GPG: 0xD14839C6 +31 318 648 688 / i...@bit.nl _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
