Finding Unix OS Block Size

Block Size for different Operating Systems
512 bytes - Solaris, AIX, Windows NT/2000,
Linux, Irix, DG/UX OpenVMS, NetWare, UnixWare, DYNIX/ptx
1024 bytes - HP-UX, Tru64 Unix
2048 bytes - SCO Unix, Reliant Unix
4096 bytes - MVS, MPE/ix


The following commands give the block size

select max(lebsz) from sys.x$kccle;
(Note: The log block size is the unit for the setting of the log_checkpoint_interval, _log_io_size and max_dump_file_size parameters)

$ fstyp -v /dev/dsk/c1d0s6  | grep devbsize
$ df /opt/oracle
/opt/oracle        (/dev/dsk/c1d0s6   ):42448742 blocks  6413020 files

DO NOT USE THE FOLLOWING :
df -g  grep 'block size'

(Note: the available & used free blocks given by the command df -g are based on the OS block size -see list above ; also use the first 2 methods to find- not the BLOCK SIZE value returned by df -g )