svn commit: r222319 - head/sbin/newfs

[Kirk McKusick]

Author: mckusick
Date: Thu May 26 18:22:49 2011
New Revision: 222319
URL: http://svn.freebsd.org/changeset/base/222319

Log:
  Raise the default blocksize for UFS/FFS filesystems from
  16K to 32K and the default fragment size from 2K to 4K.
  
  The rational is that most disks are now running with 4K
  sectors.  While they can (slowly) simulate 512-byte sectors
  by doing a read-modify-write, it is desirable to avoid this
  functionality.  By raising the minimum filesystem allocation
  to 4K, the filesystem will never trigger the small sector
  emulation.
  
  Also, the growth of disk sizes has lead us to double the
  default block size about every ten years.  The rise from 8K
  to 16K blocks was done in 2001.  So, by the 10-year metric,
  the time has come for 32K blocks.
  
  Discussed at: May 2011 BSDCan Developer Summit
  Reference: http://wiki.freebsd.org/201105DevSummit/FileSystems

Modified:
  head/sbin/newfs/newfs.h

Modified: head/sbin/newfs/newfs.h
==============================================================================
--- head/sbin/newfs/newfs.h	Thu May 26 17:38:00 2011	(r222318)
+++ head/sbin/newfs/newfs.h	Thu May 26 18:22:49 2011	(r222319)
@@ -47,8 +47,8 @@
  *	sectorsize <= DESFRAGSIZE <= DESBLKSIZE
  *	DESBLKSIZE / DESFRAGSIZE <= 8
  */
-#define	DFL_FRAGSIZE	2048
-#define	DFL_BLKSIZE	16384
+#define	DFL_FRAGSIZE	4096
+#define	DFL_BLKSIZE	32768
 
 /*
  * Cylinder groups may have up to MAXBLKSPERCG blocks. The actual