[Pvfs2-developers] server crash on startup with millions of files

[Phil Carns]

> Can we conclude this discussion?  In summary:
> 
> * The current comparison function causes bad IO patterns for iterate  on 
> the dspace db.  We can change it but the disk format will change  in new 
> releases.
> 
>     - If we change it, either we check a version number and provide the  
> right comparison function, or we perform migration to the new storage  
> format.
> 
>     - If we don't change it, we can still improve performance by  
> iterating from the last entry to the first, but we can't use  
> DB_MULTIPLE_KEY, which also improves performance for big filesystems.

I don't really have a preference either way.

> * If we change PVFS_ds_position from uint32_t to uint64_t, we can use  
> the handle as the position, and avoid opening the dspace db with the  
> RECNO flag, which is killing our performance on writes.

I think this sounds good too.  We would be happy to help test any 
combination of the options you list.

-Phil