Thanks, everyone:-) I'm still not very clear. Do these cache "capabilities" only apply to metadata operations or both metadata and data? -----邮件原件----- 发件人: David Disseldorp [mailto:ddiss@xxxxxxx] 发送时间: 2017年4月19日 16:46 收件人: 许雪寒 抄送: ceph-users@xxxxxxxxxxxxxx 主题: Re: Does cephfs guarantee client cache consistency for file data? Hi, On Wed, 19 Apr 2017 08:19:50 +0000, 许雪寒 wrote: > I’m new to cephfs. I wonder whether cephfs guarantee client cache consistency for file content. For example, if client A read some data of file X, then client B modified the X’s content in the range that A read, will A be notified of the modification? Yes, clients are granted fine-grained cache "capabilities" by the MDS. These capabilities can be revoked to trigger a flush of cached content, prior to satisfying a request from a separate client. Jeff Layton did a nice write up on this: https://jtlayton.wordpress.com/2016/09/01/cephfs-and-the-nfsv4-change-attribute/ Cheers, David _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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