Hi, I am currently trying to test the read performance of a glusterfs file system and understand its speed characteristics. This glusterfs file system is made of 4 machines with identical hardware and OS/software configuration. This filesystem is mounted onto 4 clients again with identical hardware and OS/software configuration. The gluster volume has the following configuration. ~~~ $ sudo gluster volume info gvd2_cache_128MB Volume Name: gvd2_cache_128MB Type: Distribute Volume ID: ee88b666-3130-44c5-b055-d19c42cf7b5b Status: Started Number of Bricks: 4 Transport-type: tcp Bricks: Brick1: eridani:/mnt/raid6/glusterfs_distributed_export_cache_128MB Brick2: sargas:/mnt/raid6/glusterfs_distributed_export_cache_128MB Brick3: toliman:/mnt/raid6/glusterfs_distributed_export_cache_128MB Brick4: alphard:/mnt/raid6/glusterfs_distributed_export_cache_128MB Options Reconfigured: performance.cache-size: 128MB ~~~ I have selected 3 files from each of four machines, and all 12 files have the same file size, as. ~~~ eridani /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_6 eridani /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_29 eridani /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_7 sargas /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_31 sargas /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_27 sargas /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_5 toliman /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_12 toliman /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_16 toliman /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_32 alphard /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_25 alphard /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_23 alphard /mnt/raid6/glusterfs_distributed_export_cache_128MB/benchmark/sync/ddfile_22 ~~~ Then I run `dd` in client machines, and I got the following read speed. ~~~ ddfile_5 55.3 MB/s ddfile_16 63.2 MB/s ddfile_12 76.0 MB/s ddfile_16 61.8 MB/s ddfile_27 55.4 MB/s ddfile_23 63.2 MB/s ddfile_32 76.0 MB/s ddfile_12 61.9 MB/s ddfile_31 55.4 MB/s ddfile_25 63.2 MB/s ddfile_16 76.1 MB/s ddfile_27 61.9 MB/s ddfile_12 56.2 MB/s ddfile_12 63.3 MB/s ddfile_22 76.1 MB/s ddfile_31 61.9 MB/s ddfile_16 56.2 MB/s ddfile_22 63.4 MB/s ddfile_25 76.1 MB/s ddfile_5 61.9 MB/s ddfile_22 56.2 MB/s ddfile_27 63.4 MB/s ddfile_27 76.1 MB/s ddfile_22 62.0 MB/s ddfile_25 56.2 MB/s ddfile_32 63.4 MB/s ddfile_5 76.1 MB/s ddfile_23 62.0 MB/s ddfile_32 56.2 MB/s ddfile_31 63.5 MB/s ddfile_23 76.2 MB/s ddfile_25 62.0 MB/s ddfile_23 56.3 MB/s ddfile_5 63.6 MB/s ddfile_31 76.2 MB/s ddfile_32 62.1 MB/s ddfile_7 57.7 MB/s ddfile_29 63.8 MB/s ddfile_29 77.3 MB/s ddfile_7 63.9 MB/s ddfile_29 58.1 MB/s ddfile_7 64.0 MB/s ddfile_7 77.4 MB/s ddfile_29 64.0 MB/s ddfile_6 59.3 MB/s ddfile_6 65.0 MB/s ddfile_6 79.1 MB/s ddfile_6 67.4 MB/s ~~~ I found that files from machine `eridani` have the fastest read speed in all 4 client machines, and roughly the read speed is ordered with the ordered bricks in the server machines. Do you know whether the order of bricks affects the read speed of the files in the volume? Best regards, Jin