Hi Longguang, Basically, if *all* remote servers become inaccessible, you have two bad choices: 1) Wait for the remote servers to become accessible. This is Ceph's current behavior. This is also NFS' behavior in its default "hard mount" mode. 2) Throw away data and metadata, but keep running This is NFS' behavior if you have done a "soft mount." Neither one of these choices is really good. That's why Ceph's focus is on keeping the filesystem running even if a few nodes go down. We have talked about implementing "soft mount" semantics for Ceph, but I don't think it's been done yet (Sage, correct me if I'm wrong here?) Also, you could get soft mount semantics by using libceph to access the filesystem rather than the kernel client. Userspace programs usnig libceph can always be killed in mid-write or read. A lot of system administrators don't like soft mount semantics though. Think carefully if that's really what you want. cheers, Colin On Sun, Feb 13, 2011 at 5:21 PM, Longguang Yue <longguang_yue@xxxxxxxxxxxxxxxxxxx> wrote: > When client lose its connection with ceph, then ls /mnt/ceph, it will > hang all the time > Remount does not work. > Thanks > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
