Sage created an issue to track this: http://tracker.newdream.net/issues/1122 Based on the differences between the FUSE and kernel clients, it's probably just readahead settings. :) -Greg On Tue, May 31, 2011 at 3:01 AM, Fyodor Ustinov <ufm@xxxxxx> wrote: > On 05/31/2011 01:50 AM, Fyodor Ustinov wrote: >> >> Hi! >> >> Fresh 0.28.2 cluster. >> >> Why reading two times slower than the writing by dd, but rados show >> different. >> (Second question - why rados bench crash on read test?) >> >> >> root@gate0:/mnt# dd if=/dev/zero of=aaa bs=1024000 count=10000 >> 10000+0 records in >> 10000+0 records out >> 10240000000 bytes (10 GB) copied, 64.5598 s, 159 MB/s >> >> root@gate0:/mnt# dd if=aaa of=/dev/null bs=1024000 >> 10000+0 records in >> 10000+0 records out >> 10240000000 bytes (10 GB) copied, 122.513 s, 83.6 MB/s >> root@gate0:/mnt# > > Additional. fuse vs kernel mount > > fuse: > > root@gate0:/mnt# dd if=/dev/zero of=bbb bs=1024000 count=10000 > conv=fdatasync > 10000+0 records in > 10000+0 records out > 10240000000 bytes (10 GB) copied, 75.7654 s, 135 MB/s > > root@gate0:/mnt# dd if=bbb of=/dev/null bs=1024000 > 10000+0 records in > 10000+0 records out > 10240000000 bytes (10 GB) copied, 101.613 s, 101 MB/s > > > kernel: > > root@gate0:/mnt# rm bbb > root@gate0:/mnt# dd if=/dev/zero of=bbb bs=1024000 count=10000 > conv=fdatasync > 10000+0 records in > 10000+0 records out > 10240000000 bytes (10 GB) copied, 73.143 s, 140 MB/s > > root@gate0:/mnt# dd if=bbb of=/dev/null bs=1024000 > 10000+0 records in > 10000+0 records out > 10240000000 bytes (10 GB) copied, 150.84 s, 67.9 MB/s > root@gate0:/mnt# > > What? Ok. reboot. After reboot: > > root@gate0:/mnt# rm bbb > root@gate0:/mnt# dd if=/dev/zero of=bbb bs=1024000 count=10000 > conv=fdatasync > 10000+0 records in > 10000+0 records out > 10240000000 bytes (10 GB) copied, 68.9618 s, 148 MB/s > > root@gate0:/mnt# dd if=bbb of=/dev/null bs=1024000 > 10000+0 records in > 10000+0 records out > 10240000000 bytes (10 GB) copied, 165.564 s, 61.8 MB/s > root@gate0:/mnt# > > > Hmm... unmount kernel and mount fuse... > > root@gate0:/mnt# cd > root@gate0:~# umount /mnt > root@gate0:~# cfuse -m 10.5.51.230:/ /mnt > ** WARNING: Ceph is still under development. Any feedback can be directed > ** > ** at ceph-devel@xxxxxxxxxxxxxxx or http://ceph.newdream.net/. > ** > cfuse[1102]: starting ceph client > cfuse[1102]: starting fuse > root@gate0:~# cd /mnt/ > root@gate0:/mnt# dd if=bbb of=/dev/null bs=1024000 > 10000+0 records in > 10000+0 records out > 10240000000 bytes (10 GB) copied, 93.076 s, 110 MB/s > root@gate0:/mnt# > > > What the hell? > > > > WBR, > Fyodor. > > -- > 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 > -- 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
