>> 1 Use case table.
>>
>> i. we decided on an implementation constraint to store both file
layouts
>> as attributes of objects in a redirection layer in the client. These
>> layouts would be obtained from the MDS cluster, see (iv)
>>
>> ii. We decided that locks would be taken in a hierarchical manner -
>> the flash cache would run a LDLM and locks would be taken there.
>>
>> iii. Correctness would be handled automatically through the
>> hierarchy.
>>
>
>
>
>> However, to avoid a lot of reading "write only locks" used
>> when entire pages are written are probably desirable (i.e. the caching
>> infrastructure on the flash OST''s is different from a Lustre
client).
>>
>>
>
>
If a client writes a full page, the page should not first be read by the
flash cache. Almost too obvious perhaps.
- Peter -
