Re: Samba speed

[Theodore Tso <tytso@MIT.EDU>]

On Tue, Dec 09, 2008 at 05:25:29PM +1100, ronnie sahlberg wrote:
> 
> Its not as simple as "the redirector does it every 128k".   the
> redirector does this but it varies from run to run and from client to
> client.
> It is very common to see this happening in 60-64kb strides   and other
> strides as well.
> 
> It is probably some interaction with how large the actual i/o that the
> application did internally to the cache and some other thing.
> but anyway, it varies a lot. it is not always 128k.

Is there a maximum stride size used by the redirector?  i.e., will it
use something bigger than 128k?  In any case, increasing the ext3
reservation window size should still be helpful.  It's OK if we
increase it to 32 blocks (128k, on a 4k block filesystem), and the
stride size is smaller than that.  But if it is often bigger than
128k, then then it would probably be better if samba used the
EXT3_IOC_SETRSVSZ ioctl to dynamically set the reservation size as
appropriate.

						- Ted