Craig Ringer wrote: > Bruce Momjian wrote: > > postgresqlgeneral.domain.thewild_codata@xxxxxxxxxxxxxxx wrote: > >> Hi all ! > >> > >> Reading through the list of settings returned by "SHOW ALL", I noticed > >> the "block_size" variable, which defaults to 8192. > >> > >> Running on Windows Server, my data directory is on an NTFS partition. > >> Running CHKDSK on this partition tells me that there are "4096 bytes in > >> each allocation unit." > >> > >> Are these allocation units the same as the "block_size", or does this > >> only have to do with disk geometry ? > >> If they are the same, is it important that they match ? > > > > It is not necessary they match. It just means that Postgres extends > > files in 8k chunks while your file system extends them in 4k chunks. > > ... though it's a really good idea that the Pg block size be a multiple > of the file system block size. Since most file systems use blocks of 4k > or some other 2^x power less than that, Pg's 8k block size is basically > always going to be fine. > > New hard disks are moving to 4k physical blocks, so you won't have any > issues on new 4k block disks either. Yes, it would be suboptimial if our block size was smaller than the file system block size. -- Bruce Momjian <bruce@xxxxxxxxxx> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
