Hello, we are currently investigating possiblities and performance limits of the Btrfs filesystem. Now it seems we are getting pretty poor performance for the writes and I would like to ask, if our results makes sense and if it is a result of some well known performance bottleneck.
Our setup: Server: CPU: dual socket: E5-2630 v2 RAM: 32 GB ram OS: Ubuntu server 14.10 Kernel: 3.19.0-031900rc2-generic btrfs tools: Btrfs v3.14.1 2x LSI 9300 HBAs - SAS3 12/Gbs 8x SSD Ultrastar SSD1600MM 400GB SAS3 12/Gbs Both HBAs see all 8 disks and we have set up multipathing using multipath command and device mapper. Then we using this command to create the filesystem: mkfs.btrfs -f -d raid10 /dev/mapper/prm-0 /dev/mapper/prm-1 /dev/mapper/prm-2 /dev/mapper/prm-3 /dev/mapper/prm-4 /dev/mapper/prm-5 /dev/mapper/prm-6 /dev/mapper/prm-7 We run performance test using following command: fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=test1 --filename=test1 --bs=4k --iodepth=32 --size=12G --numjobs=24 --readwrite=randwrite The results for the random read are more or less comparable with the performance of EXT4 filesystem, we get approximately 300 000 IOPs for random read. For random write however, we are getting only about 15 000 IOPs, which is much lower than for ESX4 (~200 000 IOPs for RAID10). Regards, Premek -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
