Hello. In my Ceph instalation I am uses a ssd drive for journal with direct access to a block device. At an osd is started a see in log file string: ... 1 journal _open /dev/sda1 fd 22: 19327352832 bytes, block size 4096 bytes, directio = 1, aio = 1 ... How I can change size of block from 4k to 512k, because my SSD show better perfomance witch large blocks: * With 4K (sdr6 - source, sda8 - target) dd if=/mnt/from/random of=/mnt/sda8/random bs=4k oflag=direct,dsync iostat show me the statistic: iostat -cdm 1 /dev/sda /dev/sdr Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 16198.00 0.00 126.54 0 126 sdr 126.00 15.75 0.00 15 0 * With 512K (sdr6 - source, sda8 - target) Sync: sync Clear cache: echo 1 > /proc/sys/vm/drop_caches Clear cache LSI controller: megacli -AdpCacheFlush -a0 dd if=/mnt/from/random of=/mnt/sda8/random bs=512k oflag=direct,dsync iostat show me the statistic: iostat -cdm 1 /dev/sda /dev/sdr Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 3021.00 0.01 318.00 0 318 sdr 2410.00 301.25 0.00 301 0 I think my cluster have a bottle neck in journal block size. How I can increase the size of block for journal? -- Best regards, Mike.
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