On Tue, Nov 15, 2011 at 5:16 PM, Tomas Vondra <tv@xxxxxxxx> wrote: > Dne 14.11.2011 22:58, Cody Caughlan napsal(a): >> I ran bonnie++ on a slave node, doing active streaming replication but >> otherwise idle: >> http://batch-files-test.s3.amazonaws.com/sql03.prod.html >> >> bonnie++ on the master node: >> http://batch-files-test.s3.amazonaws.com/sql01.prod.html >> >> If I am reading this right, this is my first time using it, the >> numbers dont look too good. > > I've done some benchmarks on my own (m1.xlarge instance), and the > results are these (http://pastebin.com/T1LXHru0): > > single drive > ------------ > dd writes: 62 MB/s > dd reads: 110 MB/s > bonnie seq. writes: 55 MB/s > bonnie seq. rewrite: 33 MB/s > bonnie seq. reads: 91 MB/s > bonnie seeks: 370/s > > raid 0 (4 devices) > ----------------------------- > dd writes: 220 MB/s > dd reads: 380 MB/s > bonnie seq. writes: 130 MB/s > bonnie seq. rewrite: 114 MB/s > bonnie seq. reads: 280 MB/s > bonnie seeks: 570/s > > raid 10 (4 devices) > ----------------------------- > dd writes: 90 MB/s > dd reads: 200 MB/s > bonnie seq. writes: 49 MB/s > bonnie seq. rewrite: 56 MB/s > bonnie seq. reads: 160 MB/s > bonnie seeks: 590/s > Interesting. I spun up a new m1.xlarge and did the same RAID10 config (4 drives) except with a chunk size of 512K (instead of 256K) and the machine was completely idle. Bonnie: http://batch-files-test.s3.amazonaws.com/idle-512k-chunk.html Which has similar-ish performance as yours, except for worse seeks but a bit better seq. reads. The other bonnies I sent over were NOT on idle systems. This one is the master, which receives a heavy stream of writes and some reads http://batch-files-test.s3.amazonaws.com/sql01.prod.html And this is the slave, which is all writes and no reads: http://batch-files-test.s3.amazonaws.com/sql03.prod.html How did you build your RAID array? Maybe I have a fundamental flaw / misconfiguration. I am doing it via: $ yes | mdadm --create /dev/md0 --level=10 -c256 --raid-devices=4 /dev/xvdb /dev/xvdc /dev/xvdd /dev/xvde $ pvcreate /dev/md0 $ vgcreate lvm-raid10 /dev/md0 $ lvcreate -l 215021 lvm-raid10 -n lvm0 $ blockdev --setra 65536 /dev/lvm-raid10/lvm0 $ mkfs.xfs -f /dev/lvm-raid10/lvm0 $ mkdir -p /data && mount -t xfs -o noatime /dev/lvm-raid10/lvm0 /data -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
