On Aug 12, 2013, at 7:41 PM, Josh Durgin <josh.durgin@xxxxxxxxxxx> wrote: > On 08/12/2013 07:18 PM, PJ wrote: >> >> If the target rbd device only map on one virtual machine, format it as >> ext4 and mount to two places >> mount /dev/rbd0 /nfs --> for nfs server usage >> mount /dev/rbd0 /ftp --> for ftp server usage >> nfs and ftp servers run on the same virtual machine. Will file system >> (ext4) help to handle the simultaneous access from nfs and ftp? > > I doubt that'll work perfectly on a normal disk, although rbd should > behave the same in this case. Consider what happens when to be some > issues when the same files are modified at once by the ftp and nfs > servers. You could run ftp on an nfs client on a different machine > safely. > Modern Linux kernels will do a bind mount when a block device is mounted on 2 different directories. Think directory hard links. Simultaneous access will NOT corrupt ext4, but as Josh said modifying the same file at once by ftp and nfs isn't going produce good results. With file locking 2 nfs clients could coordinate using advisory locking. David Zafman Senior Developer http://www.inktank.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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