On Sat, Mar 23, 2024 at 3:08 PM duluxoz <duluxoz@xxxxxxxxx> wrote: > > > On 23/03/2024 18:00, Alexander E. Patrakov wrote: > > Hi Dulux-Oz, > > > > CephFS is not designed to deal with mobile clients such as laptops > > that can lose connectivity at any time. And I am not talking about the > > inconveniences on the laptop itself, but about problems that your > > laptop would cause to other clients. The problems stem from the fact > > that MDSes give out "caps" to clients, which are, essentially, > > licenses to do local caching. If another client wants to access the > > same file, the MDS would need to contact the laptop and tell it to > > release the caps - which is no longer possible. Result: a health > > warning and delays/hangs on other clients. > > > > The proper solution here is to use NFSv3 (ideally with a userspace > > client instead of a kernel mount). NFSv3, because v4 has leases which > > bring the problem back. And this means that you cannot use cephadm to > > deploy this NFS server, as cephadm-deployed NFS-Ganesha is hard-coded > > to speak only NFSv4. > > > > SAMBA server with oplocks disabled, and, again, a userspace client > > could be another solution. > > > > If you decide to disregard this advice, here are some tips. > > > > With systemd, configuring autofs is as easy as adding > > "x-systemd.automount,x-systemd.idle-timeout=1min,noauto,nofail,_netdev" > > to your /etc/fstab line. This applies both to CephFS and NFS. > > > > For kernel-based NFSv3 mounts, consider adding "nolock". > > > > Another CephFS-specific mount option that somewhat helps with > > reconnects is "recover_session=clean". > > > > -- > > Alexander E. Patrakov > Hi Alex, and thanks for getting back to me so quickly (I really > appreciate it), > > So from what you said it looks like we've got the wrong solution. > Instead, (if I'm understanding things correctly) we may be better off > setting up a dedicated Samba server with the CephFS mounts, and then > using Samba to share those out - is that right? Almost right. Please set up a cluster of two SAMBA servers with CTDB, for high availability. -- Alexander E. Patrakov _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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