[Dovecot] Single instance storage - testing please

[Timo Sirainen]

On 27.8.2010, at 2.24, Michael Orlitzky wrote:

>>> Have a utility that updates all (or a subset) of them.
>> 
>> That won't be necessary. Once the hash changes, the new files are
>> created with new hash function and it doesn't matter if the old hash
>> is broken because you can't generate new files with it anymore
>> anyway.
>> 
> 
> Won't files hashed with the old function begin to dupe though?

You mean new hash would become a duplicate of the old? Well ..

1) It's highly unlikely to happen, especially because with the new hash function there again shouldn't be a way to create any specific hash.

2) As long as byte-by-byte comparison is always done, collisions don't matter much anyway (if you can reliably reproduce them, that could lead to some kind of DoS by filling the filesystem, but again once hash function is changed this couldn't be done anymore).

3) The filename can be made different, making the collision impossible. Either because of different hash length or by manually adding some specific character there.