Hi Sheng, Sorry I misspoke in my previous email. The clients may all have the capability to read and write but none of them will be able to **cache** reads/writes or **buffer** writes. They rely on synchronous read/write with the OSDs for consistency/atomicity. On Fri, Jul 21, 2017 at 9:19 AM, sheng qiu <herbert1984106@xxxxxxxxx> wrote: > so when multiple write clients or a mix of read and write clients > accessing same file, the previous cached data of this file on all > clients will be revoked. Yes. > And the following multi-clients' write or mixed read and write > accessing to that file will become synchronous. Writes/reads are become synchronous, yes. > On Tue, Jul 18, 2017 at 9:41 AM, Patrick Donnelly <pdonnell@xxxxxxxxxx> wrote: >> On Tue, Jul 18, 2017 at 9:17 AM, sheng qiu <herbert1984106@xxxxxxxxx> wrote: >>> Hi Patrick, >>> >>> thanks for your quick response. >>> just one concern, if disable direct I/O, multiple clients access same >>> file via different mount point on different machines, will it cause >>> data inconsistency? >> >> No, but you'll still effectively have synchronous I/O because only one >> writer will have write capabilities from the MDS. >> >> -- >> Patrick Donnelly -- Patrick Donnelly -- 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
