dealing with mke2fs -T option

[Theodore Tso]

On Sun, May 27, 2007 at 10:30:18PM -0400, Bryan Kadzban wrote:
> The -T option exists to tweak the number of entries available in the
> inode table, based on the size of the filesystem.

The -T option tweaks more than just the number of inodes in the inode
table, actually.  It can control other things as well, including the
blocksize and what features are enabled.  Check out the mke2fs.conf
man page, on moderately recent versions of e2fsprogs.  You can
customize what different filesystem types mean, so if you want to make
some new filesysstem type which is especially useful in your
environment (i.e., "oracle_tablespace") you can do so.  If you think
it might be generally useful, let me know and I might include it in
the default /etc/mke2fs.conf file. 

> If there's a variant of -T that takes an explicit size-per-created-inode
> value, then I'd try that, with 32Mb as the size-per-created-inode.  (Or
> possibly 16Mb, to give yourself some wiggle room.)  OTOH, the
> "largefile4" option is probably fairly close to what you want, too: it
> leaves some space available if you create some smaller files, and
> (AFAIK) having 8 times as many inodes available doesn't waste much disk
> space.

Youc an specify the the inode-ratio explicitly using the -i flag to
mke2fs, or if you know exactly how many inodes you want, you can
specify the exact number of inodes in the inode table using the -N
option.  It's all in the mke2fs man page....

							- Ted