看过类似的文章，多数是讲的文件系统的blocksize，不知道这是否和oracle block size有啥关系，我试着发现，即使是文件系统blocks
看过类似的文章，多数是讲的文件系统的blocksize，不知道这是否和oracle block size有啥关系，我试着发现，，即使是文件系统blocksize，oracle blocksize 也可以比这个filesystem block size 小的。
sql> select * from v$version;
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oracle database 10g enterprise edition release 10.2.0.4.0 - prod
pl/sql release 10.2.0.4.0 - production
core    10.2.0.4.0      production
tns for linux: version 10.2.0.4.0 - production
nlsrtl version 10.2.0.4.0 - production
sql> create tablespace test datafile '/install/test_tbs1.ora' size 2m blocksize 2k;
tablespace created.
[root@rhel4a ~]# tune2fs -l /dev/sdc1|grep -i block
block count:              1048233
reserved block count:    52411
free blocks:              828704
first block:              0
block size:              4096
reserved gdt blocks:      255
blocks per group:        32768
inode blocks per group:  512
reserved blocks uid:      0 (user root)
reserved blocks gid:      0 (group root)
journal backup:          inode blocks
[root@rhel4a ~]# mount -l
/dev/sda2 on / type ext3 (rw) [/]
none on /proc type proc (rw)
none on /sys type sysfs (rw)
none on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw) [/boot]
none on /dev/shm type tmpfs (rw)
/dev/sdb1 on /oracle10g type ext3 (rw) []
/dev/sdc1 on /install type ext3 (rw) []
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
configfs on /config type configfs (rw)
ocfs2_dlmfs on /dlm type ocfs2_dlmfs (rw)
/dev/sdd1 on /oracle10g/oradata/orcl type ocfs2 (rw,_netdev,datavolume,heartbeat=local) [oradatafiles]
oracleasmfs on /dev/oracleasm type oracleasmfs (rw)
[root@rhel4a ~]# stat -f /install
  file: /install
    id: 0        namelen: 255    type: ext2/ext3
blocks: total: 1031769    free: 828190    available: 775779    size: 4096
inodes: total: 524288    free: 521290   
[root@rhel4a ~]# dumpe2fs /dev/sdc1|grep 'block size'
dumpe2fs 1.35 (28-feb-2004)
block size:              4096
从这里是不是可以说oracle block size 和 filesystem blocksize没什么直接的关系呢？
linux: file block size is selected at the time of high-level formatting。
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the log block size is platform. specific, and can be found out using the following query: (size in bytes)
select max(lebsz) from x$kccle
most platforms have log block size of 512, but hpux has 1k, and tru64 has blocksize of 2k if my memory serves me well.
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oracle给出的查找os block size的方法：
to find the os block size in windows.
kindly run the below sql statement
select lebsz from x$kccle;
which gives the os block size.
in unix:
goto the directory $oracle_home/bin/ and run the command dbfsize. (is available on unix only)
example: $oracle_home/bin/dbfsize
you can find your log block size in bytes with the following query (connected as sys or internal):
select distinct lebsz from x$kccle;
this is the unit in which you should set the log_checkpoint_interval parameter (otherwise known as the operating system block size). some sample sizes are:
o/s log block size
======= ==============
solaris 512 bytes
hp-ux 1024 bytes
nt 512 bytes
openvms 512 bytes
digital unix 1024 bytes
to get it from the operating system, try grep dev_bsize /usr/include/sys/param.h
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