Re: wip-librbd-caching

[Martin Mailand <martin@tuxadero.com>]

Am 12.04.2012 21:45, schrieb Sage Weil:
> The config options you'll want to look at are client_oc_* (in case you
> didn't see that already :).  "oc" is short for objectcacher, and it isn't
> only used for client (libcephfs), so it might be worth renaming these
> options before people start using them.

Hi,

I changed the values and the performance is still very good and the 
memory footprint is much smaller.

OPTION(client_oc_size, OPT_INT, 1024*1024* 50)    // MB * n
OPTION(client_oc_max_dirty, OPT_INT, 1024*1024* 25)    // MB * n  (dirty 
OR tx.. bigish)
OPTION(client_oc_target_dirty, OPT_INT, 1024*1024* 8) // target dirty 
(keep this smallish)
// note: the max amount of "in flight" dirty data is roughly (max - target)

But I am not quite sure about the meaning of the values.
client_oc_size Max size of the cache?
client_oc_max_dirty max dirty value before the writeback starts?
client_oc_target_dirty ???


-martin