Hello, Has anyone some experience using defragmentation tools on Linux against tablespaces ? we are facing fragmentation problems with postgres instances having a few TB of data. ( RAID 5 ) I/O througput decreased from 300MB/s to 160. - We first moved some schemas to separate servers. After that we still have 150'000 tables in 1.5 TB - Now we are in the process of vacuuming FULL historical tables which are not written anymore. This seems to improve the I/O considerably Our remaining issue is that the free space fragmentíon is still suboptimal so that fragmention will probably start again soon. Would it make sense to use a tool like e4defrag (http://www.linux.org/threads/online-defragmentation.4121/) in order to defrag the free space ? And how safe is it to use such a tool against a running postgres instance? many thanks, Marc Mamin
