Ext3 users - May 2005 - mke2fs options for very large filesystems

>Yes, if you are creating larger files.  By default e2fsck assumes the
average
>file size is 8kB and allocates a corresponding number of inodes there.  If,
>for example, you are storing lots of larger files there (digital photos,
MP3s,
>etc) that are in the MB range you can use "-t largefile" or
"-t largefile4"
>to specify an average file size of 1MB or 4MB respectively.  You can also
>use -i or -N (see man page) to override the default bytes-per-inode value.
Wouldn't -T largefile already be making choices about the default 
bytes-per-inode?

How could I make my own determination about what values are most 
appropriate for -i and -N? My filesystems are generally several 
hundreds of gigabytes, filled with files that average about one 
megabyte in size.
-- 

Maurice Volaski, mvolaski at aecom.yu.edu
Computing Support, Rose F. Kennedy Center
Albert Einstein College of Medicine of Yeshiva University

On Thu, May 19, 2005 at 01:40:34PM -0400, Maurice Volaski
wrote:
> Wouldn't -T largefile already be making choices about the default 
> bytes-per-inode?
> 
> How could I make my own determination about what values are most 
> appropriate for -i and -N? My filesystems are generally several 
> hundreds of gigabytes, filled with files that average about one 
> megabyte in size.
Well, "mke2s -i 1048576" will create an inode for every megabyte
(1,048,576 byte) of space on the filesystem.  However, once you create
a filesystem, it's not possible to increase the number of inodes in
that filesystem afterwards.  Also, symbolic links also take up inodes,
as do block and character devices.  So in general you want to
overallocate inodes somewhat.  For example, if you specify "mke2fs -i
524288" then you will be creating twice as many inodes, since you are
asking mke2fs to create an inode for every 512k of space.

						- Ted