Hi, I'm lost. Please give me a hint. I'm currently fighting with myself of whether to use 8k blocks (pg's native) or 64k Blocks (more data) as stripe set size. ...of course to get maximum performance. I want to setup a stripe set over 4 disks on a Solaris Sparc box with a stripe block size in question. I found these arguments pro and contra either decision: 8k: + Postgres native (on Sparc Solaris) block size. + considdering random access to memory mapped pages this will distribute access over all phys. disks + read and write of near blocks are not agglomerated (read for example a 32k block) so this is as equal as good, even better because a block distance of not 4 makes two disks read/write - but exactly this may be bad, since this is one disk access that could have been used by another query. - Wal-files get written sequencially and in chunks of 8*8k which causes all 4 disks to work (be not avl. for other queries) a sequencial scan should be equal on boht block sizes (given that a table is bigger than 64k) 64k: - not a native access. Maybe up to 8 requests on the same 64k block cause 8 accesses (this should apply to 8k as well) + writing a random 8k block seems to just write one 8k block ? not read a 64 and then... + 64k are more data whilst being 'the same work' as 8k + a wal-segment can be written on just one disk whilst the others remain free for queries. - the distribution of data is not that fine grained What are you usually configuring? Here: Ultrasparc, Sol9, Metadisk, Several SCSI-disks, ufs Thanks
