How to know OS Block size in Unix..?

Hi,

How to know OS Block size in Unix..?

What is the command..?

The log file block size is same as the os block size so try following

select distinct lebsz from x$kccle;

df -kg

df -kg is not a valid command , at least on AIX system

Another alternative did not work either

SQL> select distinct lebsz from x$kccle;
select distinct lebsz from x$kccle
*
ERROR at line 1:
ORA-00942: table or view does not exist


Any corrections?

Did u try with sys user, It works here oracle 9i Rls 2

$sqlplus '/as sysdba'
SQL> select distinct lebsz from x$kccle;

LEBSZ
----------
512

SQL>

Yep,

It worked if connected as SYS. Thanks!

AIX df -P

I suspect that df -P does not give you real OS block size. In below example df -P gives you count of 512 bytes blocks , but df -k gives you output in 1024 bytes blocks on the same system.
So , what is OS block size in this case?


% df -P
Filesystem 512-blocks Used Available Capacity Mounted on
/dev/hd4 262144 43224 218920 17% /
/dev/hd2 4194304 3789888 404416 91% /usr

% df -k
Filesystem 1024-blocks Free %Used Iused %Iused Mounted on
/dev/hd4 131072 109460 17% 2321 4% /
/dev/hd2 2097152 202208 91% 32232 7% /usr
/dev/hd9var 655360 483808 27% 911 1% /var
/dev/hd3 1179648 1116664 6% 295 1% /tmp

df -P shows space in 512k block size which is OS block size.

Below is an abstract from man pages for du command:


The block count includes indirect blocks of each file. Block count is calculated in 512-byte units independent of the cluster size used by the system .
Specifying the -k flag calculates the block count in 1024-byte units

Another words du command can not be used to determine OS block size.

My mistake df -P was not the right command. 'du' shows the total disk usage for file system or directory. Its much simpler than we thought.Just create a directory and see the size of empty directory created which is nothing but OS bloxk size.

$mkdir tempdir
$ls -l