Is a block size of 4096 a good idea both for the filesystem and postgresql? The analysis here: http://www.fuzzy.cz/en/articles/benchmark-results-hdd-read-write-pgbench/ appears to suggest that at least for database block sizes of 4096 read/write performance is much higher than for smaller block sizes. Rory On 09/03/12, Rory Campbell-Lange (rory@xxxxxxxxxxxxxxxxxx) wrote: > ...An ancillary question is whether a 4096 block size is a good idea. > I suppose we will be using XFS which I understand has a default block > size of 4096 bytes. > > RAID 10 > -------------------------------------- > Read sequential > > BS MB/s IOPs > 512 0129.26 264730.80 > 1024 0229.75 235273.40 > 4096 0363.14 092965.50 > 16384 0475.02 030401.50 > 65536 0472.79 007564.65 > 131072 0428.15 003425.20 > -------------------------------------- > Write sequential > > BS MB/s IOPs > 512 0036.08 073908.00 > 1024 0065.61 067192.60 > 4096 0170.15 043560.40 > 16384 0219.80 014067.57 > 65536 0240.05 003840.91 > 131072 0243.96 001951.74 > -------------------------------------- > Random read > > BS MB/s IOPs > 512 0001.50 003077.20 > 1024 0002.91 002981.40 > 4096 0011.59 002968.30 > 16384 0044.50 002848.28 > 65536 0156.96 002511.41 > 131072 0170.65 001365.25 > -------------------------------------- > Random write > > BS MB/s IOPs > 512 0000.53 001103.60 > 1024 0001.15 001179.20 > 4096 0004.43 001135.30 > 16384 0017.61 001127.56 > 65536 0061.39 000982.39 > 131072 0079.27 000634.16 > -------------------------------------- -- Rory Campbell-Lange rory@xxxxxxxxxxxxxxxxxx Campbell-Lange Workshop www.campbell-lange.net 0207 6311 555 3 Tottenham Street London W1T 2AF Registered in England No. 04551928 -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
