Eugene, Thanks for all your response. I still wonder how the nfs writes go fine when their is enough free memory. We did some dd tests writing and reading 16GB file to NFS filesystem in 64K chunks. >From vmstat we see a lot of memory was freed during read operation, but not wirte. Could this be the reason? # time dd if=/dev/zero of=/zulu/staging/testfile bs=64k count=262144 262144+0 records in 262144+0 records out 17179869184 bytes (17 GB) copied, 846.982 seconds, 20.3 MB/s real 14m6.990s user 0m2.998s sys 9m21.523s # time dd if=/zulu/staging/testfile of=/dev/null bs=64k 262144+0 records in 262144+0 records out 17179869184 bytes (17 GB) copied, 779.67 seconds, 22.0 MB/s real 12m59.678s user 0m0.499s sys 2m9.118s ******* vmstat capture during dd read test ******** ******************************************************** procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------ r b swpd free buff cache si so bi bo in cs us sy id wa st 0 0 84 222292 156132 15151496 0 0 0 18 1028 192 0 0 100 0 0 0 0 84 222292 156136 15151496 0 0 0 42 1016 174 0 0 99 0 0 0 0 84 222292 156136 15151496 0 0 0 25 1025 178 2 0 98 0 0 0 1 84 14317360 156136 1088028 0 0 0 9 1032 180 0 40 52 8 0 0 1 84 14281060 156136 1124412 0 0 0 34 1438 276 0 6 46 48 0 1 1 84 14178340 156136 1227224 0 0 0 6 1931 427 2 18 36 44 0 0 1 84 14069272 156136 1336580 0 0 0 14 1868 456 1 24 36 39 0 0 1 84 13948188 156140 1457640 0 0 0 17 1918 430 0 20 37 43 0 0 1 84 13821468 156140 1584260 0 0 0 9 2054 451 2 20 36 42 0 0 1 84 13661860 156140 1743656 0 0 0 8 2228 524 0 27 35 37 0 Thanks. On Sat, Jan 2, 2010 at 5:58 PM, Eugene Vilensky <evilensky@xxxxxxxxx> wrote: > > Also what is the output of df for this particular volume? What about > > the storage aggregate? For NetApp you need some free space inside the > > volume, so that you are not stuck waiting for free space to be created > > from deleted files (it takes time for blocks to be freed after a DEL), > > and also plenty of free space at the aggregate level for new writes. > > And one last thing, make sure all best-practices are being followed > for the back-end storage that resides behind the V-series NetApp. > While the NetApp services the NFS, it is really the back end disks > that are being ultimately written to, so make sure whether it is > HDS/EMC/whatever, it is properly configured. Misconfigured storage is > unfortunately very easy to do. > > -- > redhat-list mailing list > unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > https://www.redhat.com/mailman/listinfo/redhat-list > -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
