>Number:         2978
>Category:       kern
>Synopsis:       NFS files' st_blksize == 512, which is probably too small.
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Sat Nov 30 11:35:00 1996
>Last-Modified:
>Originator:     Chris G. Demetriou
>Organization:
Kernel Hackers 'r' Us
>Release:        NetBSD-current, November 30, 1996
>Environment:
System: NetBSD bunnahabhain.pdl.cs.cmu.edu 1.2B NetBSD 1.2B (GENERIC) #271: Sat Nov 30 11:00:17 EST 1996 cgd@bunnahabhain.pdl.cs.cmu.edu:/usr/src/sys/arch/alpha/compile/GENERIC alpha


>Description:
	stat(2) says that the st_blksize field of struct stat is the
	"optimal file sys I/O ops blocksize."

	For NFS files (and directories), st_blksize is always set to
	512.  It's not at all clear that this is the "optimal" file
	system I/O block size.  A more plausible value is the maximum
	read or write RPC size (pick one, they're both currently the
	same in our code).

>How-To-Repeat:
	stat() NFS files, note that their st_blksize is 512, and remember
	everything you've ever learned about the fact that doing small
	I/Os is bad.

>Fix:
	Pick a better value (one is proposed above), and use that instead
	of hard-coding 512.
>Audit-Trail:
>Unformatted: