On Mon, Aug 30, 2010 at 12:09 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote: > On Fri, Aug 27, 2010 at 06:08:25PM -0500, Peng Yu wrote: >> Hi, >> >> I use the following command to search for some directory. >> >> find -L some_dir -type d -name some_name >> >> If I'm on the machine that has some_dir locally, the run time is >> real 0m0.199s >> user 0m0.048s >> sys 0m0.140s >> >> If I'm on another machine that sees the same directory by NFS (NFS3). >> the run time is >> real 0m6.509s >> user 0m0.090s >> sys 0m1.380s >> >> There are 30 time speed difference. Is this normal? Is there any NFS >> parameter that I should tune to make the latter faster? > > How many directories are there in some_dir? What's the round trip time > (e.g. as reported by ping) to the server? If you repeate the find > immediately, is it faster? > > This can indeed by much slower if it requires revalidating the cached > attributes of each file. Please see below for the answers of you questions. $ find . -type d|wc 1491 1491 53372 Search the directory as a local directory $ time find . -name 'data.frame' -type d ./library/base/data.frame ./library/base/data.frame/data.frame real 0m0.044s user 0m0.012s sys 0m0.028s Search the directory as a NFS directory. The same command runs three 3 times in series. $ time find . -name 'data.frame' -type d ./library/base/data.frame ./library/base/data.frame/data.frame real 0m2.205s user 0m0.040s sys 0m0.430s $ time find . -name 'data.frame' -type d ./library/base/data.frame ./library/base/data.frame/data.frame real 0m1.203s user 0m0.060s sys 0m0.120s $ time find . -name 'data.frame' -type d ./library/base/data.frame ./library/base/data.frame/data.frame real 0m1.227s user 0m0.040s sys 0m0.200s Ping the NFS server gives me ttl=64 time=0.156 ms. Please let me know if there is more information needed. -- Regards, Peng -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
