[GENERAL] Block_Size on NTFS
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 ? Thanks for your help ! Regards, -- Arnaud Lesauvage -- Sent via pgsql-general mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Block_Size on NTFS
Bruce Momjian - [email protected] a écrit : [email protected] wrote: 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. Thanks for your answer Bruce. So I guess it is good practice to have postgresql's "block_size" set to an exact multiplie of the filesystem's block_size, right ? Regards -- Arnaud Lesauvage -- Sent via pgsql-general mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Block_Size on NTFS
[email protected] wrote: > Bruce Momjian - [email protected] a > ?crit : > > [email protected] wrote: > >> 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. > > Thanks for your answer Bruce. > So I guess it is good practice to have postgresql's "block_size" set to > an exact multiplie of the filesystem's block_size, right ? Yes. -- Bruce Momjian 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 ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
