Seem that's is ok too on debian jessie (with an extra boost with rbd_cache true) Maybe is it related to old glibc on debian wheezy ? debian jessie: rbd_cache=false : iops=202985 : %Cpu(s): 21,9 us, 9,5 sy, 0,0 ni, 66,1 id, 0,0 wa, 0,0 hi, 2,6 si, 0,0 st debian jessie: rbd_cache=true : iops=215290 : %Cpu(s): 27,9 us, 10,8 sy, 0,0 ni, 58,8 id, 0,0 wa, 0,0 hi, 2,6 si, 0,0 st ubuntu vivid : rbd_cache=false : iops=201089 %Cpu(s): 21,3 us, 12,8 sy, 0,0 ni, 61,8 id, 0,0 wa, 0,0 hi, 4,1 si, 0,0 st ubuntu vivid : rbd_cache=true : iops=197549 %Cpu(s): 27,2 us, 15,3 sy, 0,0 ni, 53,2 id, 0,0 wa, 0,0 hi, 4,2 si, 0,0 st debian wheezy : rbd_cache=false: iops=161272 %Cpu(s): 28.4 us, 15.4 sy, 0.0 ni, 52.8 id, 0.0 wa, 0.0 hi, 3.4 si, 0.0 st debian wheezy : rbd_cache=true : iops=135893 %Cpu(s): 30.0 us, 15.5 sy, 0.0 ni, 51.5 id, 0.0 wa, 0.0 hi, 3.0 si, 0.0 st jessie perf report ------------------ + 9,18% 3,75% fio libc-2.19.so [.] malloc + 6,76% 5,70% fio libc-2.19.so [.] _int_malloc + 5,83% 5,64% fio libc-2.19.so [.] _int_free + 5,11% 0,15% fio libpthread-2.19.so [.] __libc_recv + 4,81% 4,81% swapper [kernel.kallsyms] [k] intel_idle + 3,72% 0,37% fio libpthread-2.19.so [.] pthread_cond_broadcast@@GLIBC_2.3.2 + 3,41% 0,04% fio libpthread-2.19.so [.] 0x000000000000efad + 3,31% 0,54% fio libpthread-2.19.so [.] pthread_cond_wait@@GLIBC_2.3.2 + 3,19% 0,09% fio libpthread-2.19.so [.] __lll_unlock_wake + 2,52% 0,00% fio librados.so.2.0.0 [.] ceph::buffer::create_aligned(unsigned int, unsigned int) + 2,09% 0,08% fio libc-2.19.so [.] __posix_memalign + 2,04% 0,26% fio libpthread-2.19.so [.] __lll_lock_wait + 2,02% 0,13% fio libc-2.19.so [.] _mid_memalign + 1,95% 1,91% fio libc-2.19.so [.] __memcpy_sse2_unaligned + 1,88% 0,08% fio libc-2.19.so [.] _int_memalign + 1,88% 0,00% fio libc-2.19.so [.] __clone + 1,88% 0,00% fio libpthread-2.19.so [.] start_thread + 1,88% 0,12% fio fio [.] thread_main + 1,37% 1,37% swapper [kernel.kallsyms] [k] native_write_msr_safe + 1,29% 0,05% fio libc-2.19.so [.] __lll_unlock_wake_private + 1,24% 1,24% fio libpthread-2.19.so [.] pthread_mutex_trylock + 1,24% 0,29% fio libc-2.19.so [.] __lll_lock_wait_private + 1,19% 0,21% fio librbd.so.1.0.0 [.] std::_List_base<ceph::buffer::ptr, std::allocator<ceph::buffer::ptr> >::_M_clear() + 1,19% 1,19% fio libc-2.19.so [.] free + 1,18% 1,18% fio libc-2.19.so [.] malloc_consolidate + 1,14% 1,14% fio [kernel.kallsyms] [k] get_futex_key_refs.isra.13 + 1,10% 1,10% fio [kernel.kallsyms] [k] __schedule + 1,00% 0,28% fio librados.so.2.0.0 [.] ceph::buffer::list::append(char const*, unsigned int) + 0,96% 0,00% fio librbd.so.1.0.0 [.] 0x000000000005b2e7 + 0,96% 0,96% fio [kernel.kallsyms] [k] _raw_spin_lock + 0,92% 0,21% fio librados.so.2.0.0 [.] ceph::buffer::list::append(ceph::buffer::ptr const&, unsigned int, unsigned int) + 0,91% 0,00% fio librados.so.2.0.0 [.] 0x000000000006e6c0 + 0,90% 0,90% swapper [kernel.kallsyms] [k] __switch_to + 0,89% 0,01% fio librbd.so.1.0.0 [.] 0x00000000000ce1f1 + 0,89% 0,89% swapper [kernel.kallsyms] [k] cpu_startup_entry + 0,87% 0,01% fio librados.so.2.0.0 [.] 0x00000000002e3ff1 + 0,86% 0,00% fio libc-2.19.so [.] 0x00000000000dd50d + 0,85% 0,85% fio [kernel.kallsyms] [k] try_to_wake_up + 0,83% 0,83% swapper [kernel.kallsyms] [k] __schedule + 0,82% 0,82% fio [kernel.kallsyms] [k] copy_user_enhanced_fast_string + 0,81% 0,00% fio librados.so.2.0.0 [.] 0x0000000000137abc + 0,80% 0,80% swapper [kernel.kallsyms] [k] menu_select + 0,75% 0,75% fio [kernel.kallsyms] [k] _raw_spin_lock_bh + 0,75% 0,75% fio [kernel.kallsyms] [k] futex_wake + 0,75% 0,75% fio libpthread-2.19.so [.] __pthread_mutex_unlock_usercnt + 0,73% 0,73% fio [kernel.kallsyms] [k] __switch_to + 0,70% 0,70% fio libstdc++.so.6.0.20 [.] std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::string const&) + 0,70% 0,36% fio librados.so.2.0.0 [.] ceph::buffer::list::iterator::copy(unsigned int, char*) + 0,70% 0,23% fio fio [.] get_io_u + 0,67% 0,67% fio [kernel.kallsyms] [k] finish_task_switch + 0,67% 0,32% fio libpthread-2.19.so [.] pthread_rwlock_unlock + 0,67% 0,00% fio librados.so.2.0.0 [.] 0x00000000000cea98 + 0,64% 0,00% fio librados.so.2.0.0 [.] 0x00000000002e3f87 + 0,63% 0,63% fio [kernel.kallsyms] [k] futex_wait_setup + 0,62% 0,62% swapper [kernel.kallsyms] [k] enqueue_task_fair -- 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