linux-ext4 - Re: mkfs.ext4: high default -i value undocumented

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Date:	Tue, 03 Mar 2009 17:19:31 -0600
From:	Eric Sandeen <sandeen@...hat.com>
To:	Jan Engelhardt <jengelh@...ozas.de>
CC:	linux-ext4@...r.kernel.org, kzak@...hat.com
Subject: Re: mkfs.ext4: high default -i value undocumented

Jan Engelhardt wrote:
> Hi,
> 
> 
> Creating an ext4 filesystem on a 4 GB image file (to be loop-mounted 
> later) gives me 256K inodes. Choosing -i 4096 instead gives 1M, which 
> would mean the default for -i is 16384. 

That's right, look in /etc/mke2fs.conf:

[defaults]
        base_features =
sparse_super,filetype,resize_inode,dir_index,ext_attr
        blocksize = 4096
        inode_size = 256
        inode_ratio = 16384

> Besides me finding 16384 a 
> little unreasonable (XFS offers 2M inodes by default), 

XFS is a totally different beast, because it dynamically allocates
inodes.  It doesn't really offer *anything* by default.

Which part of a 16384-data-bytes-to-inode-count ratio do you find
unreasonable?  Do you find it unreasonably high, or unreasonably low?

> the big 
> point is that the mke2fs manpage (belonging to util-linux, hence Cc) 

not so much:
$ rpm -qf /usr/share/man/man8/mke2fs.8.gz
e2fsprogs-1.41.3-2.fc10.x86_64

> does not mention this 16384 default.
> Hope this can be addressed.

You could send a patch :)

-Eric
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