Re: XATTRs in NFS?

[Ric Wheeler <rwheeler@redhat.com>]

On 10/27/2013 08:44 PM, Myklebust, Trond wrote:
> On Oct 27, 2013, at 8:27 PM, Christoph Anton Mitterer <calestyo@scientia.net> wrote:
>
>> On Mon, 2013-10-28 at 00:17 +0000, Myklebust, Trond wrote:
>>> ...and if the checksums are any good, then all you need to do to
>>> substitute a database is to realise that a good data checksum is
>>> invariant under renames.
>> Don't quite see what you mean...
>>
>> Sure the checksums stay the same, but consider you have many millions of
>> files, and you moved them around and thus the paths in the DB are
>> incorrect... verifying the files will become very much a pain in the
>> a**, especially when multiple files don't verify anymore.
>>
>> Or what if you have many small similar files, where errors could lead to
>> a checksum that was a correct one for another file,... when the paths
>> are no longer valid you cannot know if this was a correct file or not.
> If you have lots of small files, and you really do need to associate them uniquely with the checksum, then try something like:
>
> 	ln <filename> /path/to/database/<SHA512 identifier>.<inode number>
>
> Hard links and inode numbers are also generally invariant under 'mv'.
>
> Trond--
>

Then you end up with large directories and an extra name per inode that needs to 
be stored and extra lookups for each file when you do a whole file system crawl.

Certainly not as easy as adding and xattrs with that information :)

Ric