>> First the database was on a partition where compression was enabled, I >> changed it to an uncompressed one to see if it makes a difference thinking >> maybe the cpu couldn't handle the load. > It made little difference in my case. > > My regular gmirror partition seems faster: > dd bs=8k count=25600 if=/dev/zero of=./test > 25600+0 records in > 25600+0 records out > 209715200 bytes transferred in 1.513112 secs (138598612 bytes/sec) > > the zfs compressed partition also goes faster: > dd bs=8k count=25600 if=/dev/zero of=./test > 25600+0 records in > 25600+0 records out > 209715200 bytes transferred in 0.979065 secs (214199479 bytes/sec) > but this one didn't really go that fast in my test (maybe 10%)
Please can you run iozone and look for low random write performance with small blocks? (4k) http://www.slashroot.in/linux-file-system-read-write-performance-test Also please can you CC to the list with your replies to my on-list emails? Graeme Bell -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
