Re: DB_BLOCK_SIZE set to the highest value

Dino Hsu <dino1_at_ms1.hinet.net> wrote in message news:<ol4ugt0p70871ckuuab2qsjq5ep41rs487_at_4ax.com>...
> On Fri, 25 May 2001 09:35:50 -0400, Mike Jay <mikejay_at_mitre.org>
> wrote:
>
> >
> >Using the "df -g" command (no quotes) on the local system to check
> >for the optimal value, my system has 8192 block size so that's what
> >I use for the DB_BLOCK_SIZE in my initTHESID.ora pfile.
> >
>
> It doesn't work on my Linux Red Hat 7.1.
>
> [root_at_localhost /root] df -g
> df: invlid option -- g
> Try `df --help' for more information
>
> [root_at_localhost /root] df --help
> Usage: df [OPTION]... [FILE]...
> Show information about the filesystem on which each FILE resides,
> or all filesystems by default.
>
> -a, --all include filesystems having 0 blocks
> --block-size=SIZE use SIZE-byte blocks
> -h, --human-readable print sizes in human readable format (e.g., 1K
> 234M 2G)
> -H, --si likewise, but use powers of 1000 not 1024
> -i, --inodes list inode information instead of block usage
> -k, --kilobytes like --block-size=1024
> -l, --local limit listing to local filesystems
> -m, --megabytes like --block-size=1048576
> --no-sync do not invoke sync before getting usage info
> (default)
> -P, --portability use the POSIX output format
> --sync invoke sync before getting usage info
> -t, --type=TYPE limit listing to filesystems of type TYPE
> -T, --print-type print filesystem type
> -x, --exclude-type=TYPE limit listing to filesystems not of type
> TYPE
> -v (ignored)
> --help display this help and exit
> --version output version information and exit
>
> Report bugs to <bug-fileutils_at_gnu.org>.
>
> Dino

Equivalent to df -g on most UNIXes, you can use this Perl one-liner to find that Linux is 4k, the only UNIX if you call it UNIX that I know is not 8k:

perl -e '@a=stat("."); print $a[11]'

which is a convenient way to get "st_blksize A hint as to the "best" unit size for I/O operations" (from Solaris 2.6, which is SVR4; I can't find a BSD system to get the man page at this moment). Note that when Oracle says file system block size, it really means I/O size.

Yong Huang
yong321_at_yahoo.com Received on Sun May 27 2001 - 23:46:09 CDT