Could be. Say it needs to get the appropriate locks before it can read the file. In that case, the latency will be a big factor.
Read the notes section in the 1.4 user's guide. It attempts to explain how the fs works. Lorenzo Milesi wrote: > I suppose rsync takes ages in reading all directory tree and directory > listing, as it has to dig it all! > This shouldn't be affected by drbd "writes", isn't it? Is it due to high > latency? > > thanks! > > > Il giorno lun, 08/12/2008 alle 17.15 -0800, Sunil Mushran ha scritto: > >> ocfs2 does not have a concept of "primary". While we do use >> lower node number as a tie breaker in the dlm, that in itself >> should not be affect the performance much. >> >> See what rsync is doing. >> >> Lorenzo Milesi wrote: >> >>> Thanks again. >>> >>> Another curiosity: as I told we have a rsync backup running on one node. >>> If that node is set "primary" (node number 0 in cluster.conf) that rsync >>> takes up to 4h for transferring very few files, while if I set it >>> "secondary" it takes 20m! >>> >>> >>> >>> Il giorno lun, 08/12/2008 alle 12.33 -0800, Sunil Mushran ha scritto: >>> >>> >>>> ocfs2's interconnect usage is latency sensitive. It does not use >>>> much bandwidth. While it has small packets, it has lots of them. >>>> It has been written with a low latency gige private interconnect >>>> in mind. >>>> >>>> In your setup you are using drbd which is replicating all block >>>> writes across the interconnect. That is bandwidth sensitive. >>>> >>>> The performance of the ocfs2 file system (all fses actually) is partly >>>> dependant on the underlying block device. If the block device is >>>> slow, the overall performance of the fs will be slow. >>>> >>>> Lorenzo Milesi wrote: >>>> >>>> >>>>> Il giorno mar, 02/12/2008 alle 12.11 -0800, Sunil Mushran ha scritto: >>>>> >>>>> >>>>> >>>>>> The interconnect is your bottleneck. >>>>>> >>>>>> >>>>>> >>>>> thanks for your answer. what could be the minimum bandwidth for letting >>>>> ocfs2 work fine? >>>>> >>>>> thanks >>>>> >>>>> >>>>> >>>>> >>>> >>>> >> _______________________________________________ Ocfs2-users mailing list [email protected] http://oss.oracle.com/mailman/listinfo/ocfs2-users
