2004-06-08 21:12:09

by Timothy Miller

[permalink] [raw]
Subject: Increasing number of inodes after format?

I was involved in a discussion a while back where it was explained that
ext2/3 allocate a certain maximum number of inodes at format time, and
you cannot increase that number later.

It was also mentioned that one or more of the journaling file systems
(XFS, JFS, Reiser, etc.) either dynamically allocated inodes or could
increase the maximum later if the pre-allocated set got used up.

Could someone please repeat for me which filesystems have dynamic
maximum inode counts?

Thanks.


2004-06-09 00:33:07

by Nathan Scott

[permalink] [raw]
Subject: Re: Increasing number of inodes after format?

On Tue, Jun 08, 2004 at 05:27:11PM -0400, Timothy Miller wrote:
> I was involved in a discussion a while back where it was explained that
> ext2/3 allocate a certain maximum number of inodes at format time, and
> you cannot increase that number later.
>
> It was also mentioned that one or more of the journaling file systems
> (XFS, JFS, Reiser, etc.) either dynamically allocated inodes or could
> increase the maximum later if the pre-allocated set got used up.
>
> Could someone please repeat for me which filesystems have dynamic
> maximum inode counts?

XFS does dynamic inode allocation, there is no preallocated set.
Steve also recently implemented dynamic space reclaim for ondisk
inode clusters too, once they're no longer used. XFS puts a cap
on the amount of space that can be used for inodes at mkfs time
(25% iirc), and this can be adjusted later via "xfs_growfs -m".

I don't know enough about the other filesystems to answer for them
though.

cheers.

--
Nathan

2004-06-09 09:42:31

by Jan Kara

[permalink] [raw]
Subject: Re: Increasing number of inodes after format?

> I was involved in a discussion a while back where it was explained that
> ext2/3 allocate a certain maximum number of inodes at format time, and
> you cannot increase that number later.
>
> It was also mentioned that one or more of the journaling file systems
> (XFS, JFS, Reiser, etc.) either dynamically allocated inodes or could
> increase the maximum later if the pre-allocated set got used up.
>
> Could someone please repeat for me which filesystems have dynamic
> maximum inode counts?
ReiserFS also does not have any particular limit on the number of inodes
(because it actually does not have any ;).

Honza
--
Jan Kara <[email protected]>
SuSE CR Labs

2004-06-09 10:07:09

by Christoph Hellwig

[permalink] [raw]
Subject: Re: Increasing number of inodes after format?

On Wed, Jun 09, 2004 at 11:42:18AM +0200, Jan Kara wrote:
> ReiserFS also does not have any particular limit on the number of inodes
> (because it actually does not have any ;).

they're just called stat_data in reiserfs.

2004-06-09 16:09:01

by Hans Reiser

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Subject: Re: Increasing number of inodes after format?

Christoph Hellwig wrote:

>On Wed, Jun 09, 2004 at 11:42:18AM +0200, Jan Kara wrote:
>
>
>> ReiserFS also does not have any particular limit on the number of inodes
>>(because it actually does not have any ;).
>>
>>
>
>they're just called stat_data in reiserfs.
>-
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>
>
>
and there is no limit on them, but there is an objectid limit which is
32 bits in V3 and 64 bits in V4.

2004-06-09 23:58:25

by Dave Kleikamp

[permalink] [raw]
Subject: Re: Increasing number of inodes after format?

On Tue, 2004-06-08 at 16:27, Timothy Miller wrote:
> I was involved in a discussion a while back where it was explained that
> ext2/3 allocate a certain maximum number of inodes at format time, and
> you cannot increase that number later.
>
> It was also mentioned that one or more of the journaling file systems
> (XFS, JFS, Reiser, etc.) either dynamically allocated inodes or could
> increase the maximum later if the pre-allocated set got used up.
>
> Could someone please repeat for me which filesystems have dynamic
> maximum inode counts?

JFS dynamically allocates inodes as needed. An inode extent (consisting
of 32 inodes) will also be freed if all of its inodes are freed.
--
David Kleikamp
IBM Linux Technology Center