[Ocfs2-users] debugfs.ocfs2 and Feature Incompat

[Stefan Priebe - allied internet ag]

Hi!

Thanks for your answer but i'm still a little bit confused.

I'm running ocfs2 tools git HEAD (middle of may) on each machine with a 
2.6.32.12 kernel. Also the disk was formatted using:
mkfs.ocfs2 --fs-feature-level=max-features -L ocfs2disk -N 10 -T mail -v 
/dev/sdb

So i thought that i can now use features like unwritten, inline-data and 
indexed-dirs.

Stefan

Sunil Mushran schrieb:
> On 06/01/2010 04:06 AM, Stefan Priebe - allied internet ag wrote:
> 
> <snip>
>>           Feature Compat: 3 backup-super strict-journal-super
>>           Feature Incompat: 8016 sparse extended-slotmap inline-data
>> metaecc xattr indexed-dirs refcount
>>           Tunefs Incomplete: 0
>>           Feature RO compat: 1 unwritten
>>
> <snip>
> 
>> But why is inline-data, indexed-dirs and so on incompatible?
> 
> incompat means that a version of the fs not aware of this feature
> should not mount the fs. And that fsck should abort. Users encountering
> this error need to mount the fs with a newer version of the fs. Or, use
> tunefs.ocfs2 to disable that feature.
> 
> Similarly, ro compat features means that a version of the fs not aware
> of the feature can mount fs in read-only mode only.
> 
> As to which feature is incompat/ro/compat is a function of the disk format
> change involved. Changes that do not negatively affect the functioning when
> mounted with an older version are "compat". Changes that will corrupt the
> fs if mounted with an older version are "incompat". "ro compat" are changes
> that will work as long as the older fs does not write to it.